commit 8b7252dad411fa111d7ed96cf7db6e68832fd168
Author: Jean-Michel Tremblay <jeanmi.tremblay@gmail.com>
Date:   Wed Jun 17 21:40:12 2026 -0400

    Initial commit: HSA receipt tracker
    
    Go app for capturing and archiving HSA-eligible receipts: OIDC/PKCE auth
    against Authelia, SQLite storage with dual-write (filesystem + DB blob),
    mobile-first upload, and DB export.
    
    Adds AI receipt classification: a config.json catalog of people and
    categories (seeded into the DB on startup), a prompt builder that derives
    name-order/initial variants from the data (with same-surname ambiguity
    handling), and an Anthropic tool-use client behind POST /classify. Tests
    run against a mock endpoint; a live integration test is env-gated to the
    cheapest model.
    
    Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..f16ebe9
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,41 @@
+# Copy to .env and fill in. .env is gitignored.
+# Local-dev values shown; for production use the https URLs.
+
+# OIDC issuer (Authelia)
+ISSUER_URL=https://auth.maisym.com
+
+# OIDC client — must match the client registered in Authelia
+OIDC_CLIENT_ID=hsa-tracker
+OIDC_CLIENT_SECRET=<plaintext from secret.sh — the one you saved>
+
+# Where Authelia redirects back. Must be registered in the client's redirect_uris.
+# Local dev:
+REDIRECT_URL=http://localhost:8080/callback
+# Production would be: https://hsa.maisym.com/callback
+
+# Group that gates access (403 if the user isn't in it)
+REQUIRED_GROUP=hsa-users
+
+# Any random string; used to derive the session-cookie encryption key.
+# Generate one with: openssl rand -base64 32
+SESSION_SECRET=
+
+# Listen address
+LISTEN_ADDR=:8080
+
+# Storage (defaults shown; relative paths are resolved from the app's working dir).
+# For the LXC deployment use absolute paths under /var/lib/hsa.
+DB_PATH=./data/hsa.db
+STORAGE_DIR=./data/receipts
+
+# Max upload size in megabytes (reject larger). Camera photos can be ~10MB.
+MAX_UPLOAD_MB=32
+
+# People + categories catalog (seeded into the DB on startup).
+CONFIG_PATH=./config.json
+
+# Receipt auto-classification (Anthropic). Leave CLAUDE_API_KEY empty to disable.
+# Tests never need this: they use a mock endpoint (or the cheapest model when
+# HSA_CLASSIFY_IT=1 is set explicitly).
+CLAUDE_API_KEY=
+CLASSIFY_MODEL=claude-opus-4-8
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a5d03de
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,21 @@
+# Compiled binary (root only; not the cmd/hsa/ package dir)
+/hsa
+
+# Env files (keep the example)
+*.env
+.env
+!.env.example
+
+# Local data: SQLite DB + uploaded receipt files
+data/
+*.db
+*.db-shm
+*.db-wal
+
+# Generated output from the call_claude.sh prototype
+response.json
+
+# Go build/test artifacts
+*.test
+*.out
+coverage.*
diff --git a/call_claude.sh b/call_claude.sh
new file mode 100644
index 0000000..f162fbc
--- /dev/null
+++ b/call_claude.sh
@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+IMG=/home/jm/Downloads/receipt.jpeg
+B64=$(base64 -w0 "$IMG")
+
+OUT=response.json
+
+curl -s https://api.anthropic.com/v1/messages \
+  -H "x-api-key: $CLAUDE_API_KEY" \
+  -H "anthropic-version: 2023-06-01" \
+  -H "content-type: application/json" \
+  -o "$OUT" \
+  -d @- <<EOF
+{
+  "model": "claude-opus-4-8",
+  "max_tokens": 1024,
+  "messages": [
+    {
+      "role": "user",
+      "content": [
+        {
+          "type": "image",
+          "source": { "type": "base64", "media_type": "image/jpeg", "data": "$B64" }
+        },
+        {
+          "type": "text",
+          "text": "Analyze this receipt and return ONLY a JSON object, no prose, with these fields:\n- \"person\": one of exactly \"jean-michel tremblay\", \"lynna nguyen\", or \"could not fetch\" if the name is absent or matches neither. The first and last name may appear in any order (e.g. \"Tremblay Jean-Michel\" or \"Nguyen, Lynna\"), possibly with a middle initial or accents; match on the name regardless of order or formatting.\n- \"category\": one of exactly \"pharmacy\", \"dental\", \"medical\", or \"other\".\n- \"date\": the receipt date as YYYY-MM-DD, or \"could not fetch\". Today is 2026-06-12, and the receipt date is usually within the last year or two of that (it may be a backfilled older receipt). The year is the last component; if it is only two digits, expand it to a year near the present (20YY within about 2 years of today), never far in the past or future. This is a US receipt, so read ambiguous numeric dates as MM-DD-YY.\n- \"amount\": the total as a plain number string (e.g. \"42.50\"), or \"could not fetch\"."
+        }
+      ]
+    }
+  ]
+}
+EOF
+
+echo "Raw response saved to $OUT"
+jq -r '.content[0].text' "$OUT"
+
+# Cost — Opus 4.8: $5/M input, $25/M output
+jq -r '
+  .usage as $u
+  | ($u.input_tokens // 0) as $in
+  | ($u.output_tokens // 0) as $out
+  | ($in * 5 / 1000000) as $cin
+  | ($out * 25 / 1000000) as $cout
+  | "\n--- usage ---\ninput:  \($in) tok  $\($cin * 10000 | round / 10000)\noutput: \($out) tok  $\($cout * 10000 | round / 10000)\ntotal:  $\(($cin + $cout) * 10000 | round / 10000)"
+' "$OUT"
diff --git a/cmd/hsa/main.go b/cmd/hsa/main.go
new file mode 100644
index 0000000..de60ee7
--- /dev/null
+++ b/cmd/hsa/main.go
@@ -0,0 +1,63 @@
+package main
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+
+	"maisym.com/hsa/internal/classify"
+	"maisym.com/hsa/internal/config"
+	"maisym.com/hsa/internal/storage"
+	"maisym.com/hsa/internal/web"
+)
+
+func main() {
+	// Best-effort local dev convenience: load .env if present.
+	if err := config.LoadDotEnv(".env"); err != nil {
+		log.Fatalf("loading .env: %v", err)
+	}
+
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("config: %v", err)
+	}
+
+	if err := os.MkdirAll(filepath.Dir(cfg.DBPath), 0o700); err != nil {
+		log.Fatalf("create db dir: %v", err)
+	}
+	store, err := storage.Open(cfg.DBPath)
+	if err != nil {
+		log.Fatalf("open store: %v", err)
+	}
+	defer store.Close()
+
+	// Load the people/categories catalog and seed it into the DB (insert-if-absent).
+	catalog, err := config.LoadCatalog(cfg.ConfigPath)
+	if err != nil {
+		log.Fatalf("config catalog: %v", err)
+	}
+	if err := store.Seed(catalog.CategoryNames(), catalog.PersonLabels()); err != nil {
+		log.Fatalf("seed catalog: %v", err)
+	}
+
+	// Receipt auto-classification is best-effort: only enabled when an API key is set.
+	var classifier *classify.Classifier
+	if cfg.ClassifyAPIKey != "" {
+		classifier = classify.New(cfg.ClassifyAPIKey, cfg.ClassifyModel, catalog.Persons, catalog.Categories)
+		log.Printf("receipt classification enabled (model %s)", cfg.ClassifyModel)
+	} else {
+		log.Printf("receipt classification disabled (CLAUDE_API_KEY not set)")
+	}
+
+	srv, err := web.NewServer(context.Background(), cfg, store, classifier)
+	if err != nil {
+		log.Fatalf("server init: %v", err)
+	}
+
+	log.Printf("HSA listening on %s (issuer %s)", cfg.ListenAddr, cfg.IssuerURL)
+	if err := http.ListenAndServe(cfg.ListenAddr, srv.Routes()); err != nil {
+		log.Fatalf("listen: %v", err)
+	}
+}
diff --git a/config.json b/config.json
new file mode 100644
index 0000000..91fe0ad
--- /dev/null
+++ b/config.json
@@ -0,0 +1,31 @@
+{
+  "persons": [
+    { "last": "Tremblay", "first": "Jean-Michel", "middle": "" },
+    { "last": "Nguyen",   "first": "Lynna",       "middle": "" },
+    { "last": "Tremblay", "first": "Jude",        "middle": "" },
+    { "last": "Tremblay", "first": "Alex",        "middle": "" },
+    { "last": "Tremblay", "first": "Evan",        "middle": "" }
+  ],
+  "categories": [
+    {
+      "name": "Medical",
+      "examples": ["doctor", "clinic", "hospital", "urgent care", "lab work", "copay", "physician"]
+    },
+    {
+      "name": "Dental",
+      "examples": ["dentist", "orthodontist", "cleaning", "filling", "crown", "braces"]
+    },
+    {
+      "name": "Vision",
+      "examples": ["optometrist", "eye exam", "glasses", "contact lenses", "frames"]
+    },
+    {
+      "name": "Pharmacy",
+      "examples": ["CVS", "Walgreens", "Rite Aid", "Rockville Pharmacy", "prescription", "Rx", "pharmacy copay"]
+    },
+    {
+      "name": "Other",
+      "examples": ["anything HSA-eligible that does not fit the buckets above"]
+    }
+  ]
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..70e6bb4
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,22 @@
+module maisym.com/hsa
+
+go 1.26.4
+
+require (
+	github.com/coreos/go-oidc/v3 v3.18.0
+	golang.org/x/oauth2 v0.36.0
+)
+
+require (
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/go-jose/go-jose/v4 v4.1.4 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	golang.org/x/sys v0.42.0 // indirect
+	modernc.org/libc v1.72.3 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+	modernc.org/sqlite v1.52.0 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..ad19f6d
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,27 @@
+github.com/coreos/go-oidc/v3 v3.18.0 h1:V9orjXynvu5wiC9SemFTWnG4F45v403aIcjWo0d41+A=
+github.com/coreos/go-oidc/v3 v3.18.0/go.mod h1:DYCf24+ncYi+XkIH97GY1+dqoRlbaSI26KVTCI9SrY4=
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/go-jose/go-jose/v4 v4.1.4 h1:moDMcTHmvE6Groj34emNPLs/qtYXRVcd6S7NHbHz3kA=
+github.com/go-jose/go-jose/v4 v4.1.4/go.mod h1:x4oUasVrzR7071A4TnHLGSPpNOm2a21K9Kf04k1rs08=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/ncruces/go-strftime v1.0.0 h1:HMFp8mLCTPp341M/ZnA4qaf7ZlsbTc+miZjCLOFAw7w=
+github.com/ncruces/go-strftime v1.0.0/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
+github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
+golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
+golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
+golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+modernc.org/libc v1.72.3 h1:ZnDF4tXn4NBXFutMMQC4vtbTFSXhhKzR73fv0beZEAU=
+modernc.org/libc v1.72.3/go.mod h1:dn0dZNnnn1clLyvRxLxYExxiKRZIRENOfqQ8XEeg4Qs=
+modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
+modernc.org/mathutil v1.7.1/go.mod h1:4p5IwJITfppl0G4sUEDtCr4DthTaT47/N3aT6MhfgJg=
+modernc.org/memory v1.11.0 h1:o4QC8aMQzmcwCK3t3Ux/ZHmwFPzE6hf2Y5LbkRs+hbI=
+modernc.org/memory v1.11.0/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
+modernc.org/sqlite v1.52.0 h1:p4dhYh2tXZCiyaqHwRVJDjIGKWyXayiQpThxgDzJaxo=
+modernc.org/sqlite v1.52.0/go.mod h1:tcNzv5p84E0skkmJn038y+hWJbLQXQqEnQfeh5r2JLM=
diff --git a/internal/auth/auth.go b/internal/auth/auth.go
new file mode 100644
index 0000000..8832b06
--- /dev/null
+++ b/internal/auth/auth.go
@@ -0,0 +1 @@
+package auth
diff --git a/internal/auth/authorize.go b/internal/auth/authorize.go
new file mode 100644
index 0000000..ff68682
--- /dev/null
+++ b/internal/auth/authorize.go
@@ -0,0 +1,14 @@
+package auth
+
+import "golang.org/x/oauth2"
+
+// AuthorizeURL builds the Authelia authorization redirect URL with PKCE and state.
+// challenge must be the pre-computed S256 value from ChallengeS256(verifier).
+// Extra options (e.g. the OIDC nonce) may be passed via opts.
+func AuthorizeURL(cfg *oauth2.Config, state, challenge string, opts ...oauth2.AuthCodeOption) string {
+	args := append([]oauth2.AuthCodeOption{
+		oauth2.SetAuthURLParam("code_challenge", challenge),
+		oauth2.SetAuthURLParam("code_challenge_method", "S256"),
+	}, opts...)
+	return cfg.AuthCodeURL(state, args...)
+}
diff --git a/internal/auth/authorize_test.go b/internal/auth/authorize_test.go
new file mode 100644
index 0000000..064bc7c
--- /dev/null
+++ b/internal/auth/authorize_test.go
@@ -0,0 +1,52 @@
+package auth
+
+import (
+	"net/url"
+	"strings"
+	"testing"
+
+	"golang.org/x/oauth2"
+)
+
+func TestAuthorizeURL(t *testing.T) {
+	cfg := &oauth2.Config{
+		ClientID:    "hsa-tracker",
+		RedirectURL: "https://hsa.maisym.com/callback",
+		Scopes:      []string{"openid", "profile", "email", "groups"},
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  "https://auth.maisym.com/api/oidc/authorization",
+			TokenURL: "https://auth.maisym.com/api/oidc/token",
+		},
+	}
+
+	state := "test-state-value"
+	verifier := "test-verifier-value"
+	challenge := ChallengeS256(verifier)
+
+	rawURL := AuthorizeURL(cfg, state, challenge)
+
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		t.Fatalf("AuthorizeURL returned invalid URL: %v", err)
+	}
+	q := u.Query()
+
+	if q.Get("state") != state {
+		t.Errorf("state = %q, want %q", q.Get("state"), state)
+	}
+	if q.Get("code_challenge") != challenge {
+		t.Errorf("code_challenge = %q, want %q", q.Get("code_challenge"), challenge)
+	}
+	if q.Get("code_challenge_method") != "S256" {
+		t.Errorf("code_challenge_method = %q, want S256", q.Get("code_challenge_method"))
+	}
+	if q.Get("response_type") != "code" {
+		t.Errorf("response_type = %q, want code", q.Get("response_type"))
+	}
+	scopes := q.Get("scope")
+	for _, s := range []string{"openid", "profile", "email", "groups"} {
+		if !strings.Contains(scopes, s) {
+			t.Errorf("scope %q missing from %q", s, scopes)
+		}
+	}
+}
diff --git a/internal/auth/authz.go b/internal/auth/authz.go
new file mode 100644
index 0000000..03dab8c
--- /dev/null
+++ b/internal/auth/authz.go
@@ -0,0 +1,11 @@
+package auth
+
+// IsAuthorized returns true if required is present in groups (exact, case-sensitive match).
+func IsAuthorized(groups []string, required string) bool {
+	for _, g := range groups {
+		if g == required {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/auth/authz_test.go b/internal/auth/authz_test.go
new file mode 100644
index 0000000..6119b96
--- /dev/null
+++ b/internal/auth/authz_test.go
@@ -0,0 +1,28 @@
+package auth
+
+import "testing"
+
+func TestIsAuthorized(t *testing.T) {
+	cases := []struct {
+		name     string
+		groups   []string
+		required string
+		want     bool
+	}{
+		{"in group", []string{"hsa-users"}, "hsa-users", true},
+		{"in group among others", []string{"admins", "hsa-users", "devs"}, "hsa-users", true},
+		{"empty groups", []string{}, "hsa-users", false},
+		{"nil groups", nil, "hsa-users", false},
+		{"other group only", []string{"admins"}, "hsa-users", false},
+		{"wrong case", []string{"HSA-USERS"}, "hsa-users", false},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := IsAuthorized(tc.groups, tc.required)
+			if got != tc.want {
+				t.Errorf("IsAuthorized(%v, %q) = %v, want %v", tc.groups, tc.required, got, tc.want)
+			}
+		})
+	}
+}
diff --git a/internal/auth/loginstate.go b/internal/auth/loginstate.go
new file mode 100644
index 0000000..08f6fae
--- /dev/null
+++ b/internal/auth/loginstate.go
@@ -0,0 +1,23 @@
+package auth
+
+// LoginState is the per-login data we stash in a short-lived encrypted cookie
+// during /login, to validate the response at /callback.
+type LoginState struct {
+	State    string // CSRF token echoed back in the callback
+	Verifier string // PKCE code verifier
+	Nonce    string // OIDC nonce echoed back in the ID token
+}
+
+// EncodeLoginState encrypts the login state into a cookie value.
+func EncodeLoginState(ls LoginState, key [32]byte) (string, error) {
+	return seal(key, ls)
+}
+
+// DecodeLoginState decrypts a cookie value produced by EncodeLoginState.
+func DecodeLoginState(encoded string, key [32]byte) (LoginState, error) {
+	var ls LoginState
+	if err := open(key, encoded, &ls); err != nil {
+		return LoginState{}, err
+	}
+	return ls, nil
+}
diff --git a/internal/auth/pkce.go b/internal/auth/pkce.go
new file mode 100644
index 0000000..b781c9d
--- /dev/null
+++ b/internal/auth/pkce.go
@@ -0,0 +1,24 @@
+package auth
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+)
+
+// GenerateVerifier returns a cryptographically random PKCE verifier (RFC 7636).
+// Length is 64 URL-safe characters, within the required [43, 128] range.
+func GenerateVerifier() (string, error) {
+	b := make([]byte, 48)
+	if _, err := rand.Read(b); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(b), nil
+}
+
+// ChallengeS256 returns the S256 PKCE challenge for the given verifier.
+// challenge = BASE64URL(SHA256(ASCII(verifier)))
+func ChallengeS256(verifier string) string {
+	h := sha256.Sum256([]byte(verifier))
+	return base64.RawURLEncoding.EncodeToString(h[:])
+}
diff --git a/internal/auth/pkce_test.go b/internal/auth/pkce_test.go
new file mode 100644
index 0000000..3d08652
--- /dev/null
+++ b/internal/auth/pkce_test.go
@@ -0,0 +1,54 @@
+package auth
+
+import (
+	"strings"
+	"testing"
+)
+
+// RFC 7636 Appendix B known vector.
+// verifier = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
+// expected challenge (S256) = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM"
+const (
+	rfcVerifier  = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
+	rfcChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM"
+)
+
+func TestChallengeS256_RFCVector(t *testing.T) {
+	got := ChallengeS256(rfcVerifier)
+	if got != rfcChallenge {
+		t.Errorf("ChallengeS256(%q) = %q, want %q", rfcVerifier, got, rfcChallenge)
+	}
+}
+
+func TestGenerateVerifier_Length(t *testing.T) {
+	v, err := GenerateVerifier()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(v) < 43 || len(v) > 128 {
+		t.Errorf("verifier length %d outside [43,128]", len(v))
+	}
+}
+
+func TestGenerateVerifier_URLSafe(t *testing.T) {
+	for range 20 {
+		v, err := GenerateVerifier()
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, c := range v {
+			if !strings.ContainsRune("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~", c) {
+				t.Errorf("verifier %q contains non-URL-safe char %q", v, c)
+				break
+			}
+		}
+	}
+}
+
+func TestGenerateVerifier_Unique(t *testing.T) {
+	a, _ := GenerateVerifier()
+	b, _ := GenerateVerifier()
+	if a == b {
+		t.Error("two calls returned the same verifier")
+	}
+}
diff --git a/internal/auth/session.go b/internal/auth/session.go
new file mode 100644
index 0000000..f2dc713
--- /dev/null
+++ b/internal/auth/session.go
@@ -0,0 +1,89 @@
+package auth
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/gob"
+	"fmt"
+	"io"
+	"time"
+)
+
+// Session holds the claims we care about after a successful OIDC login.
+type Session struct {
+	Subject  string    // email or sub claim
+	Groups   []string  // groups claim from Authelia
+	IssuedAt time.Time // when we issued this session cookie
+}
+
+// seal gob-encodes v and AES-256-GCM encrypts it into a base64url string.
+func seal(key [32]byte, v any) (string, error) {
+	var buf bytes.Buffer
+	if err := gob.NewEncoder(&buf).Encode(v); err != nil {
+		return "", fmt.Errorf("seal gob: %w", err)
+	}
+
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+	// nonce || ciphertext+tag
+	ciphertext := gcm.Seal(nonce, nonce, buf.Bytes(), nil)
+	return base64.RawURLEncoding.EncodeToString(ciphertext), nil
+}
+
+// open decrypts and gob-decodes a value produced by seal into v.
+// Returns an error if the value was tampered with or sealed with a different key.
+func open(key [32]byte, encoded string, v any) error {
+	data, err := base64.RawURLEncoding.DecodeString(encoded)
+	if err != nil {
+		return fmt.Errorf("open base64: %w", err)
+	}
+
+	block, err := aes.NewCipher(key[:])
+	if err != nil {
+		return err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return err
+	}
+	if len(data) < gcm.NonceSize() {
+		return fmt.Errorf("sealed value too short")
+	}
+	nonce, ciphertext := data[:gcm.NonceSize()], data[gcm.NonceSize():]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return fmt.Errorf("open decrypt: %w", err)
+	}
+
+	if err := gob.NewDecoder(bytes.NewReader(plaintext)).Decode(v); err != nil {
+		return fmt.Errorf("open gob: %w", err)
+	}
+	return nil
+}
+
+// EncodeSession serialises and encrypts a Session into a cookie value.
+func EncodeSession(s Session, key [32]byte) (string, error) {
+	return seal(key, s)
+}
+
+// DecodeSession decrypts and deserialises a cookie value produced by EncodeSession.
+func DecodeSession(encoded string, key [32]byte) (Session, error) {
+	var s Session
+	if err := open(key, encoded, &s); err != nil {
+		return Session{}, err
+	}
+	return s, nil
+}
diff --git a/internal/auth/session_test.go b/internal/auth/session_test.go
new file mode 100644
index 0000000..9eb54e8
--- /dev/null
+++ b/internal/auth/session_test.go
@@ -0,0 +1,77 @@
+package auth
+
+import (
+	"testing"
+	"time"
+)
+
+func testKey() [32]byte {
+	var k [32]byte
+	copy(k[:], "test-key-32-bytes-exactly-padded")
+	return k
+}
+
+func TestSessionRoundTrip(t *testing.T) {
+	key := testKey()
+	sess := Session{
+		Subject:  "jeanmi@example.com",
+		Groups:   []string{"hsa-users", "admins"},
+		IssuedAt: time.Now().UTC().Truncate(time.Second),
+	}
+
+	encoded, err := EncodeSession(sess, key)
+	if err != nil {
+		t.Fatalf("encode: %v", err)
+	}
+
+	got, err := DecodeSession(encoded, key)
+	if err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+
+	if got.Subject != sess.Subject {
+		t.Errorf("subject: got %q want %q", got.Subject, sess.Subject)
+	}
+	if len(got.Groups) != len(sess.Groups) || got.Groups[0] != sess.Groups[0] {
+		t.Errorf("groups: got %v want %v", got.Groups, sess.Groups)
+	}
+	if !got.IssuedAt.Equal(sess.IssuedAt) {
+		t.Errorf("issuedAt: got %v want %v", got.IssuedAt, sess.IssuedAt)
+	}
+}
+
+func TestSessionTamperedRejected(t *testing.T) {
+	key := testKey()
+	sess := Session{Subject: "someone", Groups: []string{"hsa-users"}, IssuedAt: time.Now()}
+
+	encoded, err := EncodeSession(sess, key)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Flip a byte near the end of the ciphertext.
+	b := []byte(encoded)
+	b[len(b)-4] ^= 0xFF
+	tampered := string(b)
+
+	if _, err := DecodeSession(tampered, key); err == nil {
+		t.Error("expected error for tampered cookie, got nil")
+	}
+}
+
+func TestSessionWrongKeyRejected(t *testing.T) {
+	key := testKey()
+	sess := Session{Subject: "someone", Groups: []string{"hsa-users"}, IssuedAt: time.Now()}
+
+	encoded, err := EncodeSession(sess, key)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var otherKey [32]byte
+	copy(otherKey[:], "different-key-32-bytes-padded!!!")
+
+	if _, err := DecodeSession(encoded, otherKey); err == nil {
+		t.Error("expected error for wrong key, got nil")
+	}
+}
diff --git a/internal/auth/state.go b/internal/auth/state.go
new file mode 100644
index 0000000..0e15b31
--- /dev/null
+++ b/internal/auth/state.go
@@ -0,0 +1,16 @@
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+)
+
+// GenerateState returns a cryptographically random, URL-safe state value
+// for use as a CSRF token in the OIDC authorization flow.
+func GenerateState() (string, error) {
+	b := make([]byte, 32)
+	if _, err := rand.Read(b); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(b), nil
+}
diff --git a/internal/auth/state_test.go b/internal/auth/state_test.go
new file mode 100644
index 0000000..8c16241
--- /dev/null
+++ b/internal/auth/state_test.go
@@ -0,0 +1,22 @@
+package auth
+
+import "testing"
+
+func TestGenerateState_Length(t *testing.T) {
+	s, err := GenerateState()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// 32 random bytes → 43 base64url chars (no padding)
+	if len(s) < 32 {
+		t.Errorf("state too short: %d chars", len(s))
+	}
+}
+
+func TestGenerateState_Unique(t *testing.T) {
+	a, _ := GenerateState()
+	b, _ := GenerateState()
+	if a == b {
+		t.Error("two calls returned the same state")
+	}
+}
diff --git a/internal/classify/classify.go b/internal/classify/classify.go
new file mode 100644
index 0000000..478bec3
--- /dev/null
+++ b/internal/classify/classify.go
@@ -0,0 +1,310 @@
+// Package classify calls the Anthropic API to read an HSA receipt image and
+// suggest its patient, category, date, and amount. It builds the prompt from the
+// configured people and categories (see prompt.go) and forces a structured answer
+// via tool-use so the result is always valid JSON. The HTTP endpoint is injectable
+// so tests can run against a mock (or the cheapest model) instead of paying for Opus.
+package classify
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"maisym.com/hsa/internal/config"
+)
+
+// DefaultEndpoint is the live Anthropic messages API.
+const DefaultEndpoint = "https://api.anthropic.com/v1/messages"
+
+// Suggestion is the classifier's reading of a receipt. The normalized fields are
+// nil when the model could not determine them; Category falls back to the last
+// (most general) configured category rather than nil, since it is a closed set.
+// Raw* hold the literal text the model saw, for auditing misreads.
+type Suggestion struct {
+	Person   *string `json:"person"`   // canonical person label, or nil
+	Category string  `json:"category"` // one of the configured category names
+	Date     *string `json:"date"`     // YYYY-MM-DD, or nil
+	Amount   *string `json:"amount"`   // plain number string e.g. "42.50", or nil
+
+	RawName   string `json:"raw_name"`
+	RawDate   string `json:"raw_date"`
+	RawAmount string `json:"raw_amount"`
+}
+
+// Classifier holds everything needed to classify a receipt.
+type Classifier struct {
+	APIKey     string
+	Model      string
+	Endpoint   string
+	HTTP       *http.Client
+	Persons    []config.Person
+	Categories []config.Category
+}
+
+// New builds a Classifier for the live API. Persons and categories come from the
+// catalog; pass an empty model to use a sensible default.
+func New(apiKey, model string, persons []config.Person, categories []config.Category) *Classifier {
+	if model == "" {
+		model = "claude-opus-4-8"
+	}
+	return &Classifier{
+		APIKey:     apiKey,
+		Model:      model,
+		Endpoint:   DefaultEndpoint,
+		HTTP:       &http.Client{Timeout: 60 * time.Second},
+		Persons:    persons,
+		Categories: categories,
+	}
+}
+
+const toolName = "record_receipt"
+
+// --- request / response shapes ---
+
+type apiRequest struct {
+	Model       string       `json:"model"`
+	MaxTokens   int          `json:"max_tokens"`
+	Temperature float64      `json:"temperature"`
+	System      string       `json:"system"`
+	Tools       []apiTool    `json:"tools"`
+	ToolChoice  apiToolPick  `json:"tool_choice"`
+	Messages    []apiMessage `json:"messages"`
+}
+
+type apiTool struct {
+	Name        string         `json:"name"`
+	Description string         `json:"description"`
+	InputSchema map[string]any `json:"input_schema"`
+}
+
+type apiToolPick struct {
+	Type string `json:"type"`
+	Name string `json:"name"`
+}
+
+type apiMessage struct {
+	Role    string     `json:"role"`
+	Content []apiBlock `json:"content"`
+}
+
+type apiBlock struct {
+	Type   string     `json:"type"`
+	Text   string     `json:"text,omitempty"`
+	Source *apiSource `json:"source,omitempty"`
+}
+
+type apiSource struct {
+	Type      string `json:"type"`
+	MediaType string `json:"media_type"`
+	Data      string `json:"data"`
+}
+
+type apiResponse struct {
+	Content []struct {
+		Type  string          `json:"type"`
+		Name  string          `json:"name"`
+		Input json.RawMessage `json:"input"`
+	} `json:"content"`
+	Error *struct {
+		Type    string `json:"type"`
+		Message string `json:"message"`
+	} `json:"error"`
+}
+
+type toolInput struct {
+	Person    *string `json:"person"`
+	Category  *string `json:"category"`
+	Date      *string `json:"date"`
+	Amount    *string `json:"amount"`
+	RawName   string  `json:"raw_name"`
+	RawDate   string  `json:"raw_date"`
+	RawAmount string  `json:"raw_amount"`
+}
+
+// Classify sends the receipt to the model and returns its normalized reading.
+// today is used so the date heuristics ("closest to today, never future") are
+// testable; pass time.Now().
+func (c *Classifier) Classify(ctx context.Context, today time.Time, image []byte, mimeType string) (Suggestion, error) {
+	system := BuildSystemPrompt(c.Persons, c.Categories, today.Format("2006-01-02"))
+
+	imgBlock := apiBlock{
+		Type:   "image",
+		Source: &apiSource{Type: "base64", MediaType: mimeType, Data: base64.StdEncoding.EncodeToString(image)},
+	}
+	if mimeType == "application/pdf" {
+		imgBlock.Type = "document"
+	}
+
+	reqBody := apiRequest{
+		Model:       c.Model,
+		MaxTokens:   1024,
+		Temperature: 0,
+		System:      system,
+		Tools:       []apiTool{{Name: toolName, Description: "Record the extracted receipt fields.", InputSchema: c.inputSchema()}},
+		ToolChoice:  apiToolPick{Type: "tool", Name: toolName},
+		Messages: []apiMessage{{
+			Role: "user",
+			Content: []apiBlock{
+				imgBlock,
+				{Type: "text", Text: "Read this receipt and call record_receipt."},
+			},
+		}},
+	}
+
+	payload, err := json.Marshal(reqBody)
+	if err != nil {
+		return Suggestion{}, fmt.Errorf("marshal request: %w", err)
+	}
+
+	endpoint := c.Endpoint
+	if endpoint == "" {
+		endpoint = DefaultEndpoint
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(payload))
+	if err != nil {
+		return Suggestion{}, fmt.Errorf("build request: %w", err)
+	}
+	req.Header.Set("x-api-key", c.APIKey)
+	req.Header.Set("anthropic-version", "2023-06-01")
+	req.Header.Set("content-type", "application/json")
+
+	httpClient := c.HTTP
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return Suggestion{}, fmt.Errorf("call anthropic: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return Suggestion{}, fmt.Errorf("read response: %w", err)
+	}
+
+	var ar apiResponse
+	if err := json.Unmarshal(body, &ar); err != nil {
+		return Suggestion{}, fmt.Errorf("parse response (status %d): %w", resp.StatusCode, err)
+	}
+	if ar.Error != nil {
+		return Suggestion{}, fmt.Errorf("anthropic error: %s: %s", ar.Error.Type, ar.Error.Message)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return Suggestion{}, fmt.Errorf("anthropic status %d: %s", resp.StatusCode, string(body))
+	}
+
+	for _, blk := range ar.Content {
+		if blk.Type == "tool_use" && blk.Name == toolName {
+			var in toolInput
+			if err := json.Unmarshal(blk.Input, &in); err != nil {
+				return Suggestion{}, fmt.Errorf("parse tool input: %w", err)
+			}
+			return c.normalize(in), nil
+		}
+	}
+	return Suggestion{}, fmt.Errorf("no %s tool_use in response", toolName)
+}
+
+// inputSchema is the JSON Schema the model must fill. Enums constrain person and
+// category to the configured sets; null is allowed where a field may be unknown.
+func (c *Classifier) inputSchema() map[string]any {
+	personEnum := append(allowedLabelsAny(c.Persons), nil)
+	catEnum := make([]any, 0, len(c.Categories))
+	for _, cat := range c.Categories {
+		catEnum = append(catEnum, cat.Name)
+	}
+	return map[string]any{
+		"type": "object",
+		"properties": map[string]any{
+			"person":     map[string]any{"type": []string{"string", "null"}, "enum": personEnum, "description": "Exact patient name, or null if absent/ambiguous."},
+			"category":   map[string]any{"type": "string", "enum": catEnum, "description": "Best-fit category name."},
+			"date":       map[string]any{"type": []string{"string", "null"}, "description": "Service date as YYYY-MM-DD, or null."},
+			"amount":     map[string]any{"type": []string{"string", "null"}, "description": "Total paid as a plain number, or null."},
+			"raw_name":   map[string]any{"type": "string", "description": "Literal name text read, or empty string."},
+			"raw_date":   map[string]any{"type": "string", "description": "Literal date text read, or empty string."},
+			"raw_amount": map[string]any{"type": "string", "description": "Literal amount text read, or empty string."},
+		},
+		"required": []string{"person", "category", "date", "amount", "raw_name", "raw_date", "raw_amount"},
+	}
+}
+
+// allowedLabels here returns []any for the schema enum (string labels).
+func allowedLabelsAny(persons []config.Person) []any {
+	labels := allowedLabels(persons)
+	out := make([]any, len(labels))
+	for i, l := range labels {
+		out[i] = l
+	}
+	return out
+}
+
+// normalize validates and cleans the raw tool output into a Suggestion. It guards
+// against the model returning a non-canonical person or category despite the enum.
+func (c *Classifier) normalize(in toolInput) Suggestion {
+	s := Suggestion{
+		RawName:   strings.TrimSpace(in.RawName),
+		RawDate:   strings.TrimSpace(in.RawDate),
+		RawAmount: strings.TrimSpace(in.RawAmount),
+	}
+
+	// Person: keep only if it matches a canonical label exactly.
+	if in.Person != nil {
+		if p := strings.TrimSpace(*in.Person); p != "" && !isNullish(p) {
+			for _, want := range c.Persons {
+				if strings.EqualFold(p, want.Label()) {
+					label := want.Label()
+					s.Person = &label
+					break
+				}
+			}
+		}
+	}
+
+	// Category: must be a configured name; otherwise fall back to the last
+	// (most general) category.
+	s.Category = c.fallbackCategory()
+	if in.Category != nil {
+		got := strings.TrimSpace(*in.Category)
+		for _, cat := range c.Categories {
+			if strings.EqualFold(got, cat.Name) {
+				s.Category = cat.Name
+				break
+			}
+		}
+	}
+
+	if in.Date != nil {
+		if d := strings.TrimSpace(*in.Date); d != "" && !isNullish(d) {
+			s.Date = &d
+		}
+	}
+	if in.Amount != nil {
+		if a := strings.TrimSpace(*in.Amount); a != "" && !isNullish(a) {
+			s.Amount = &a
+		}
+	}
+	return s
+}
+
+func (c *Classifier) fallbackCategory() string {
+	if len(c.Categories) == 0 {
+		return ""
+	}
+	return c.Categories[len(c.Categories)-1].Name
+}
+
+// isNullish catches stringified nulls the model may emit despite the schema.
+func isNullish(s string) bool {
+	switch strings.ToLower(s) {
+	case "null", "none", "n/a", "na", "could not fetch", "unknown":
+		return true
+	}
+	return false
+}
diff --git a/internal/classify/classify_test.go b/internal/classify/classify_test.go
new file mode 100644
index 0000000..2c89bdf
--- /dev/null
+++ b/internal/classify/classify_test.go
@@ -0,0 +1,156 @@
+package classify
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"maisym.com/hsa/internal/config"
+)
+
+func testCatalog() ([]config.Person, []config.Category) {
+	persons := []config.Person{
+		{First: "Jean-Michel", Last: "Tremblay"},
+		{First: "Lynna", Last: "Nguyen"},
+		{First: "Jude", Last: "Tremblay"},
+	}
+	categories := []config.Category{
+		{Name: "Medical", Examples: []string{"clinic"}},
+		{Name: "Pharmacy", Examples: []string{"CVS"}},
+		{Name: "Other"},
+	}
+	return persons, categories
+}
+
+// mockServer returns an httptest server that replies with a tool_use block whose
+// input is the given map, and the Classifier pointed at it.
+func mockServer(t *testing.T, input map[string]any) (*Classifier, *httptest.Server) {
+	t.Helper()
+	persons, categories := testCatalog()
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Sanity: the request must force our tool.
+		body, _ := io.ReadAll(r.Body)
+		if !strings.Contains(string(body), toolName) {
+			t.Errorf("request missing tool %q: %s", toolName, body)
+		}
+		resp := map[string]any{
+			"content": []map[string]any{
+				{"type": "tool_use", "name": toolName, "input": input},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(resp)
+	}))
+	t.Cleanup(srv.Close)
+
+	c := New("test-key", "claude-haiku-4-5-20251001", persons, categories)
+	c.Endpoint = srv.URL
+	c.HTTP = srv.Client()
+	return c, srv
+}
+
+func TestClassifyHappyPath(t *testing.T) {
+	c, _ := mockServer(t, map[string]any{
+		"person":     "Lynna Nguyen",
+		"category":   "Pharmacy",
+		"date":       "2025-11-03",
+		"amount":     "42.50",
+		"raw_name":   "Nguyen, Lynna",
+		"raw_date":   "11/03/25",
+		"raw_amount": "$42.50",
+	})
+
+	got, err := c.Classify(context.Background(), time.Now(), []byte("img"), "image/jpeg")
+	if err != nil {
+		t.Fatalf("Classify: %v", err)
+	}
+	if got.Person == nil || *got.Person != "Lynna Nguyen" {
+		t.Errorf("person = %v, want Lynna Nguyen", got.Person)
+	}
+	if got.Category != "Pharmacy" {
+		t.Errorf("category = %q, want Pharmacy", got.Category)
+	}
+	if got.Date == nil || *got.Date != "2025-11-03" {
+		t.Errorf("date = %v, want 2025-11-03", got.Date)
+	}
+	if got.Amount == nil || *got.Amount != "42.50" {
+		t.Errorf("amount = %v, want 42.50", got.Amount)
+	}
+	if got.RawName != "Nguyen, Lynna" {
+		t.Errorf("raw_name = %q", got.RawName)
+	}
+}
+
+func TestClassifyNullsAndFallback(t *testing.T) {
+	c, _ := mockServer(t, map[string]any{
+		"person":     nil,
+		"category":   "definitely-not-a-real-category",
+		"date":       nil,
+		"amount":     "null", // stringified null
+		"raw_name":   "",
+		"raw_date":   "",
+		"raw_amount": "",
+	})
+
+	got, err := c.Classify(context.Background(), time.Now(), []byte("img"), "image/jpeg")
+	if err != nil {
+		t.Fatalf("Classify: %v", err)
+	}
+	if got.Person != nil {
+		t.Errorf("person = %v, want nil", *got.Person)
+	}
+	if got.Date != nil {
+		t.Errorf("date = %v, want nil", *got.Date)
+	}
+	if got.Amount != nil {
+		t.Errorf("amount = %v, want nil (stringified null)", *got.Amount)
+	}
+	if got.Category != "Other" { // fallback to most general
+		t.Errorf("category = %q, want Other fallback", got.Category)
+	}
+}
+
+func TestClassifyRejectsNonCanonicalPerson(t *testing.T) {
+	c, _ := mockServer(t, map[string]any{
+		"person":   "Dr. Emily Smith", // a provider, not a configured patient
+		"category": "Medical",
+	})
+	got, err := c.Classify(context.Background(), time.Now(), []byte("img"), "image/jpeg")
+	if err != nil {
+		t.Fatalf("Classify: %v", err)
+	}
+	if got.Person != nil {
+		t.Errorf("person = %v, want nil (non-canonical)", *got.Person)
+	}
+}
+
+// TestClassifyIntegration hits the real API with the cheapest model. Skipped unless
+// HSA_CLASSIFY_IT=1 and CLAUDE_API_KEY are set, so normal test runs cost nothing.
+func TestClassifyIntegration(t *testing.T) {
+	if os.Getenv("HSA_CLASSIFY_IT") != "1" {
+		t.Skip("set HSA_CLASSIFY_IT=1 (and CLAUDE_API_KEY) to run the live integration test")
+	}
+	key := os.Getenv("CLAUDE_API_KEY")
+	if key == "" {
+		t.Skip("CLAUDE_API_KEY not set")
+	}
+	persons, categories := testCatalog()
+	c := New(key, "claude-haiku-4-5-20251001", persons, categories)
+
+	img, err := os.ReadFile(os.Getenv("HSA_CLASSIFY_IMG"))
+	if err != nil {
+		t.Skipf("set HSA_CLASSIFY_IMG to a receipt image: %v", err)
+	}
+	got, err := c.Classify(context.Background(), time.Now(), img, "image/jpeg")
+	if err != nil {
+		t.Fatalf("Classify: %v", err)
+	}
+	t.Logf("suggestion: %+v", got)
+}
diff --git a/internal/classify/prompt.go b/internal/classify/prompt.go
new file mode 100644
index 0000000..5565e2d
--- /dev/null
+++ b/internal/classify/prompt.go
@@ -0,0 +1,192 @@
+package classify
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"maisym.com/hsa/internal/config"
+)
+
+// NameVariants returns example renderings of one person's name as it might appear
+// on a receipt, derived from the structured (first/middle/last) data rather than
+// hand-written. `all` is the full people list, used to suppress initial-based
+// variants that would be ambiguous: with several people sharing a surname (e.g.
+// the Tremblays), "J. Tremblay" could be Jean-Michel or Jude, so neither gets it,
+// while "A. Tremblay" (unique to Alex) is kept.
+func NameVariants(p config.Person, all []config.Person) []string {
+	first := strings.TrimSpace(p.First)
+	last := strings.TrimSpace(p.Last)
+	mid := strings.TrimSpace(p.Middle)
+
+	var out []string
+	add := func(s string) {
+		s = strings.Join(strings.Fields(s), " ") // collapse whitespace
+		if s == "" {
+			return
+		}
+		for _, e := range out {
+			if e == s {
+				return
+			}
+		}
+		out = append(out, s)
+	}
+
+	// Order and punctuation variants are always unambiguous (full first name present).
+	add(first + " " + last)
+	add(last + " " + first)
+	add(last + ", " + first)
+	if mid != "" {
+		mi := initial(mid)
+		add(first + " " + mi + ". " + last)
+		add(last + ", " + first + " " + mi + ".")
+	}
+
+	// Compound first names ("Jean-Michel") yield specific multi-letter initials
+	// ("J-M", "J.M.") that are far less likely to collide — keep them if unique.
+	if parts := firstParts(first); len(parts) > 1 {
+		comp := compoundInitial(parts, "-") // J-M
+		compDot := compoundInitial(parts, ".") + "."
+		if uniqueCompound(p, all) {
+			add(comp + " " + last)
+			add(compDot + " " + last)
+		}
+	}
+
+	// A single first-initial ("J.") is only safe when no one else shares the
+	// surname with the same initial.
+	if fi := initial(first); fi != "" && uniqueSingleInitial(p, all) {
+		add(fi + ". " + last)
+		add(last + ", " + fi + ".")
+	}
+
+	return out
+}
+
+func initial(s string) string {
+	for _, r := range strings.TrimSpace(s) {
+		return strings.ToUpper(string(r))
+	}
+	return ""
+}
+
+// firstParts splits a first name on spaces and hyphens ("Jean-Michel" -> Jean, Michel).
+func firstParts(first string) []string {
+	return strings.FieldsFunc(first, func(r rune) bool { return r == '-' || r == ' ' })
+}
+
+// compoundInitial joins the initial of each part with sep: ["Jean","Michel"] -> "J-M" / "J.M".
+func compoundInitial(parts []string, sep string) string {
+	var b strings.Builder
+	for i, p := range parts {
+		if i > 0 {
+			b.WriteString(sep)
+		}
+		b.WriteString(initial(p))
+	}
+	return b.String()
+}
+
+// sameSurname reports whether q is a different person sharing p's surname.
+func sameSurname(p, q config.Person) bool {
+	return !strings.EqualFold(strings.TrimSpace(p.First), strings.TrimSpace(q.First)) &&
+		strings.EqualFold(strings.TrimSpace(p.Last), strings.TrimSpace(q.Last))
+}
+
+// uniqueSingleInitial reports whether p's first initial is unique among people
+// sharing p's surname.
+func uniqueSingleInitial(p config.Person, all []config.Person) bool {
+	fi := initial(p.First)
+	for _, q := range all {
+		if sameSurname(p, q) && initial(q.First) == fi {
+			return false
+		}
+	}
+	return true
+}
+
+// uniqueCompound reports whether p's compound first-initial is unique among people
+// sharing p's surname.
+func uniqueCompound(p config.Person, all []config.Person) bool {
+	pc := compoundInitial(firstParts(p.First), "-")
+	for _, q := range all {
+		if sameSurname(p, q) && compoundInitial(firstParts(q.First), "-") == pc {
+			return false
+		}
+	}
+	return true
+}
+
+// BuildSystemPrompt assembles the full instruction text for the classifier from the
+// catalog and today's date (YYYY-MM-DD). The catalog's canonical labels are the only
+// allowed outputs; variants and examples are presented as illustrations, never as
+// data to extract.
+func BuildSystemPrompt(persons []config.Person, categories []config.Category, today string) string {
+	var b strings.Builder
+
+	b.WriteString("You extract data from a US health-care receipt for HSA reimbursement. ")
+	b.WriteString("Call the record_receipt tool exactly once with your best reading. ")
+	b.WriteString("Never invent values; when a field is genuinely unreadable or absent, pass null for it.\n\n")
+
+	// People.
+	b.WriteString("PATIENT — who the receipt is FOR. Output one of these EXACT names, or null:\n")
+	for _, p := range persons {
+		variants := NameVariants(p, persons)
+		// Drop the canonical form itself from the "also appears as" list.
+		var also []string
+		for _, v := range variants {
+			if v != p.Label() {
+				also = append(also, v)
+			}
+		}
+		if len(also) > 0 {
+			fmt.Fprintf(&b, "  - %q (may also appear as: %s)\n", p.Label(), strings.Join(also, "; "))
+		} else {
+			fmt.Fprintf(&b, "  - %q\n", p.Label())
+		}
+	}
+	b.WriteString("Rules for the patient:\n")
+	b.WriteString("  - The variants above are formatting illustrations of the SAME person, not separate people.\n")
+	b.WriteString("  - Match on first AND last name together, in any order, with or without a comma, accents, or a middle name/initial.\n")
+	b.WriteString("  - A lone surname, or an initial that fits more than one person above (e.g. \"J. Tremblay\" could be Jean-Michel or Jude), is AMBIGUOUS — output null.\n")
+	b.WriteString("  - IGNORE everyone who is not the patient: doctors, dentists, pharmacists, nurses, providers, billing/account reps, the store manager, the cashier. Titles like Dr., MD, DDS, RPh, NP mark a provider, not a patient. A clinic, pharmacy, or business name is not a patient.\n\n")
+
+	// Categories.
+	b.WriteString("CATEGORY — output exactly one of these names (default to the most general bucket if unsure, never invent one):\n")
+	for _, c := range categories {
+		if len(c.Examples) > 0 {
+			fmt.Fprintf(&b, "  - %q: %s\n", c.Name, strings.Join(c.Examples, ", "))
+		} else {
+			fmt.Fprintf(&b, "  - %q\n", c.Name)
+		}
+	}
+	b.WriteString("\n")
+
+	// Date.
+	fmt.Fprintf(&b, "DATE — the date of SERVICE or purchase as YYYY-MM-DD, or null. Today is %s.\n", today)
+	b.WriteString("  - Receipts are contemporary: almost always within the last year or two, occasionally an older backfilled receipt, but NEVER in the future.\n")
+	b.WriteString("  - If several dates appear (service, print, due, date of birth), use the service/transaction date — not a print/due date or DOB.\n")
+	b.WriteString("  - Formats are usually numeric MM-DD-YY or MM-DD-YYYY (US order), sometimes a written month (\"Jun 5, 2025\"), and ISO YYYY-MM-DD when the first part is a 4-digit year. YY-MM-DD also occurs but is rare.\n")
+	b.WriteString("  - Expand a 2-digit year to 20YY. When a date is ambiguous, pick the interpretation CLOSEST to today without going into the future.\n\n")
+
+	// Amount.
+	b.WriteString("AMOUNT — the total the patient actually PAID (grand total / amount due / amount paid / patient responsibility) as a plain number string like \"42.50\", or null.\n")
+	b.WriteString("  - Strip currency symbols and thousands separators. Do not return a subtotal, list price, insurance-covered portion, or a single line item when a final total exists.\n\n")
+
+	// Raw echoes.
+	b.WriteString("RAW — also pass back the literal text you read for the name, date, and amount (raw_name, raw_date, raw_amount), exactly as printed, for auditing. Use \"\" if nothing was found.\n")
+	b.WriteString("If the image holds more than one receipt, read the primary (largest/topmost) one.\n")
+
+	return b.String()
+}
+
+// allowedLabels returns the canonical labels of a lookup, sorted for stable output.
+func allowedLabels(persons []config.Person) []string {
+	out := make([]string, 0, len(persons))
+	for _, p := range persons {
+		out = append(out, p.Label())
+	}
+	sort.Strings(out)
+	return out
+}
diff --git a/internal/classify/prompt_test.go b/internal/classify/prompt_test.go
new file mode 100644
index 0000000..04e0f30
--- /dev/null
+++ b/internal/classify/prompt_test.go
@@ -0,0 +1,90 @@
+package classify
+
+import (
+	"strings"
+	"testing"
+
+	"maisym.com/hsa/internal/config"
+)
+
+func contains(list []string, want string) bool {
+	for _, s := range list {
+		if s == want {
+			return true
+		}
+	}
+	return false
+}
+
+// The Tremblay family: Jean-Michel and Jude share the initial "J", so neither may
+// get a bare "J. Tremblay" variant; Alex ("A") and Evan ("E") are unique and may.
+func TestNameVariantsAmbiguousInitial(t *testing.T) {
+	all := []config.Person{
+		{First: "Jean-Michel", Last: "Tremblay"},
+		{First: "Jude", Last: "Tremblay"},
+		{First: "Alex", Last: "Tremblay"},
+		{First: "Evan", Last: "Tremblay"},
+		{First: "Lynna", Last: "Nguyen"},
+	}
+
+	jm := NameVariants(all[0], all)
+	if contains(jm, "J. Tremblay") || contains(jm, "Tremblay, J.") {
+		t.Errorf("Jean-Michel must not get an ambiguous single-initial variant: %v", jm)
+	}
+	// Compound initials are unique to Jean-Michel and should appear.
+	if !contains(jm, "J-M Tremblay") {
+		t.Errorf("Jean-Michel should get compound initial variant J-M Tremblay: %v", jm)
+	}
+
+	jude := NameVariants(all[1], all)
+	if contains(jude, "J. Tremblay") {
+		t.Errorf("Jude must not get an ambiguous single-initial variant: %v", jude)
+	}
+
+	alex := NameVariants(all[2], all)
+	if !contains(alex, "A. Tremblay") {
+		t.Errorf("Alex (unique initial) should get A. Tremblay: %v", alex)
+	}
+
+	// Lynna's surname is unique, so a single initial is fine.
+	lynna := NameVariants(all[4], all)
+	if !contains(lynna, "L. Nguyen") {
+		t.Errorf("Lynna (unique surname) should get L. Nguyen: %v", lynna)
+	}
+
+	// Order/comma variants are always present and unambiguous.
+	for _, want := range []string{"Jean-Michel Tremblay", "Tremblay Jean-Michel", "Tremblay, Jean-Michel"} {
+		if !contains(jm, want) {
+			t.Errorf("expected variant %q in %v", want, jm)
+		}
+	}
+}
+
+func TestBuildSystemPrompt(t *testing.T) {
+	persons := []config.Person{
+		{First: "Jean-Michel", Last: "Tremblay"},
+		{First: "Lynna", Last: "Nguyen"},
+	}
+	categories := []config.Category{
+		{Name: "Pharmacy", Examples: []string{"CVS", "Rx"}},
+		{Name: "Other"},
+	}
+	p := BuildSystemPrompt(persons, categories, "2026-06-17")
+
+	for _, want := range []string{
+		"Jean-Michel Tremblay", // canonical label
+		"Lynna Nguyen",
+		"Pharmacy",
+		"CVS",                // example injected
+		"2026-06-17",         // today
+		"AMBIGUOUS",          // the ambiguity rule
+		"IGNORE everyone",    // ignore-other-people rule
+		"null",               // unknown handling
+		"raw_name",           // raw echo
+		"CLOSEST to today",   // date tie-breaker
+	} {
+		if !strings.Contains(p, want) {
+			t.Errorf("system prompt missing %q", want)
+		}
+	}
+}
diff --git a/internal/config/catalog.go b/internal/config/catalog.go
new file mode 100644
index 0000000..30109fe
--- /dev/null
+++ b/internal/config/catalog.go
@@ -0,0 +1,92 @@
+package config
+
+// This file loads the editable, non-secret lists from config.json (path set by
+// CONFIG_PATH) into Go structs: the people a receipt can belong to, and the
+// categories it can fall into. It is separate from config.go, which only reads
+// environment variables (secrets, ports, paths). On startup these lists are
+// seeded into the database; the per-category "examples" are used to build the
+// receipt-classification prompt and deliberately do NOT live in the DB, so they
+// can be tuned without a schema change.
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// Catalog is the parsed content of config.json.
+type Catalog struct {
+	Persons    []Person   `json:"persons"`
+	Categories []Category `json:"categories"`
+}
+
+// Person is one possible "Who" for a receipt, stored structurally (last/first/
+// middle) so the classifier can derive the many ways a name may appear on a
+// receipt — different order, a comma, or initials.
+type Person struct {
+	Last   string `json:"last"`
+	First  string `json:"first"`
+	Middle string `json:"middle"`
+}
+
+// Category is one classification bucket plus authored examples (store names,
+// typical line items) that help the classifier decide. Examples are semantic and
+// cannot be derived from the name, so they are authored here by hand.
+type Category struct {
+	Name     string   `json:"name"`
+	Examples []string `json:"examples"`
+}
+
+// Label is the canonical display name ("First Last"), used both as the DB label
+// and as the exact string the classifier must emit. The middle name is carried
+// only to disambiguate; it is not part of the canonical label.
+func (p Person) Label() string {
+	return strings.TrimSpace(strings.TrimSpace(p.First) + " " + strings.TrimSpace(p.Last))
+}
+
+// LoadCatalog reads and validates config.json at path. A missing file is an error:
+// the app needs people and categories to function.
+func LoadCatalog(path string) (Catalog, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return Catalog{}, fmt.Errorf("read config file %q: %w", path, err)
+	}
+	defer f.Close()
+
+	var c Catalog
+	dec := json.NewDecoder(f)
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(&c); err != nil {
+		return Catalog{}, fmt.Errorf("parse config file %q: %w", path, err)
+	}
+	for i, p := range c.Persons {
+		if strings.TrimSpace(p.First) == "" || strings.TrimSpace(p.Last) == "" {
+			return Catalog{}, fmt.Errorf("person %d: first and last are required", i)
+		}
+	}
+	for i, cat := range c.Categories {
+		if strings.TrimSpace(cat.Name) == "" {
+			return Catalog{}, fmt.Errorf("category %d: name is required", i)
+		}
+	}
+	return c, nil
+}
+
+// CategoryNames returns the category labels in config order.
+func (c Catalog) CategoryNames() []string {
+	out := make([]string, 0, len(c.Categories))
+	for _, cat := range c.Categories {
+		out = append(out, cat.Name)
+	}
+	return out
+}
+
+// PersonLabels returns the canonical person labels in config order.
+func (c Catalog) PersonLabels() []string {
+	out := make([]string, 0, len(c.Persons))
+	for _, p := range c.Persons {
+		out = append(out, p.Label())
+	}
+	return out
+}
diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..83d9ebe
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,122 @@
+package config
+
+import (
+	"bufio"
+	"crypto/sha256"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// Config holds all runtime configuration, loaded from environment variables.
+type Config struct {
+	IssuerURL     string   // OIDC issuer, e.g. https://auth.maisym.com
+	ClientID      string   // OIDC client_id
+	ClientSecret  string   // OIDC client secret (plaintext)
+	RedirectURL   string   // e.g. http://localhost:8080/callback
+	RequiredGroup string   // group that gates access, e.g. hsa-users
+	SessionKey    [32]byte // AES-256 key derived from SESSION_SECRET
+	ListenAddr    string   // e.g. :8080
+	SecureCookies bool     // true when serving over https
+
+	DBPath         string // SQLite file path
+	StorageDir     string // directory for receipt files on disk
+	MaxUploadBytes int64  // reject uploads larger than this
+
+	ConfigPath     string // path to config.json (people + categories)
+	ClassifyAPIKey string // Anthropic API key; empty disables auto-classification
+	ClassifyModel  string // model id for classification
+}
+
+// Load reads configuration from the environment, validating required values.
+func Load() (Config, error) {
+	var c Config
+	var missing []string
+
+	get := func(key string) string {
+		v := strings.TrimSpace(os.Getenv(key))
+		if v == "" {
+			missing = append(missing, key)
+		}
+		return v
+	}
+
+	c.IssuerURL = get("ISSUER_URL")
+	c.ClientID = get("OIDC_CLIENT_ID")
+	c.ClientSecret = get("OIDC_CLIENT_SECRET")
+	c.RedirectURL = get("REDIRECT_URL")
+	c.RequiredGroup = get("REQUIRED_GROUP")
+	sessionSecret := get("SESSION_SECRET")
+
+	if len(missing) > 0 {
+		return Config{}, fmt.Errorf("missing required env vars: %s", strings.Join(missing, ", "))
+	}
+
+	// Derive a fixed 32-byte AES key from whatever secret string was provided.
+	c.SessionKey = sha256.Sum256([]byte(sessionSecret))
+
+	c.ListenAddr = strings.TrimSpace(os.Getenv("LISTEN_ADDR"))
+	if c.ListenAddr == "" {
+		c.ListenAddr = ":8080"
+	}
+
+	c.SecureCookies = strings.HasPrefix(c.RedirectURL, "https://")
+
+	c.DBPath = envOr("DB_PATH", "./data/hsa.db")
+	c.StorageDir = envOr("STORAGE_DIR", "./data/receipts")
+
+	maxMB := 32
+	if v := strings.TrimSpace(os.Getenv("MAX_UPLOAD_MB")); v != "" {
+		if n, err := strconv.Atoi(v); err == nil && n > 0 {
+			maxMB = n
+		}
+	}
+	c.MaxUploadBytes = int64(maxMB) * 1024 * 1024
+
+	// Domain config + classification (all optional; classification is best-effort).
+	c.ConfigPath = envOr("CONFIG_PATH", "./config.json")
+	c.ClassifyAPIKey = strings.TrimSpace(os.Getenv("CLAUDE_API_KEY"))
+	c.ClassifyModel = envOr("CLASSIFY_MODEL", "claude-opus-4-8")
+
+	return c, nil
+}
+
+func envOr(key, def string) string {
+	if v := strings.TrimSpace(os.Getenv(key)); v != "" {
+		return v
+	}
+	return def
+}
+
+// LoadDotEnv is a best-effort loader that reads KEY=VALUE lines from path into
+// the process environment if the file exists. Existing env vars are not overwritten.
+// Intended for local development convenience only.
+func LoadDotEnv(path string) error {
+	f, err := os.Open(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		key, val, ok := strings.Cut(line, "=")
+		if !ok {
+			continue
+		}
+		key = strings.TrimSpace(key)
+		val = strings.Trim(strings.TrimSpace(val), `"'`)
+		if _, exists := os.LookupEnv(key); !exists {
+			os.Setenv(key, val)
+		}
+	}
+	return scanner.Err()
+}
diff --git a/internal/receipt/receipt.go b/internal/receipt/receipt.go
new file mode 100644
index 0000000..f9f3023
--- /dev/null
+++ b/internal/receipt/receipt.go
@@ -0,0 +1,75 @@
+// Package receipt holds the receipt domain model and pure validation logic.
+package receipt
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// Receipt is a stored receipt record. Category and Who are referenced by id into
+// the categories/people lookup tables (PersonID is nil when "Who" is unset).
+type Receipt struct {
+	ID               string
+	UploadedBy       string
+	UploadedAt       time.Time
+	ReceiptDate      time.Time
+	AmountCents      int64
+	CategoryID       int64
+	PersonID         *int64
+	FilePath         string
+	ImageData        []byte
+	FileSizeBytes    int64
+	OriginalFilename string
+	MimeType         string
+	DeletedAt        *time.Time
+}
+
+// ParseAmountCents parses a positive dollar amount into integer cents without
+// using floating point. Accepts an optional leading "$", surrounding spaces, and
+// thousands separators. Rejects empty, non-numeric, more than two decimal places,
+// zero, and negative values.
+func ParseAmountCents(s string) (int64, error) {
+	s = strings.TrimSpace(s)
+	s = strings.TrimPrefix(s, "$")
+	s = strings.ReplaceAll(s, ",", "")
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return 0, fmt.Errorf("empty amount")
+	}
+	if strings.HasPrefix(s, "-") {
+		return 0, fmt.Errorf("amount must be positive")
+	}
+
+	whole, frac, hasDot := strings.Cut(s, ".")
+	if hasDot && strings.Contains(frac, ".") {
+		return 0, fmt.Errorf("invalid amount %q", s)
+	}
+	if whole == "" && frac == "" {
+		return 0, fmt.Errorf("invalid amount %q", s)
+	}
+
+	// Normalise the fractional part to exactly two digits.
+	switch len(frac) {
+	case 0:
+		frac = "00"
+	case 1:
+		frac = frac + "0"
+	case 2:
+		// ok
+	default:
+		return 0, fmt.Errorf("amount has more than two decimal places: %q", s)
+	}
+
+	var cents int64
+	for _, r := range whole + frac {
+		if r < '0' || r > '9' {
+			return 0, fmt.Errorf("invalid amount %q", s)
+		}
+		cents = cents*10 + int64(r-'0')
+	}
+	if cents <= 0 {
+		return 0, fmt.Errorf("amount must be greater than zero")
+	}
+	return cents, nil
+}
diff --git a/internal/receipt/receipt_test.go b/internal/receipt/receipt_test.go
new file mode 100644
index 0000000..5f3b296
--- /dev/null
+++ b/internal/receipt/receipt_test.go
@@ -0,0 +1,37 @@
+package receipt
+
+import "testing"
+
+func TestParseAmountCents(t *testing.T) {
+	ok := []struct {
+		in   string
+		want int64
+	}{
+		{"12.34", 1234},
+		{"0.99", 99},
+		{"100", 10000},
+		{"12.3", 1230},
+		{"12", 1200},
+		{"1234.00", 123400},
+		{"$12.34", 1234},
+		{" 12.34 ", 1234},
+		{"1,234.56", 123456},
+	}
+	for _, tc := range ok {
+		got, err := ParseAmountCents(tc.in)
+		if err != nil {
+			t.Errorf("ParseAmountCents(%q) unexpected error: %v", tc.in, err)
+			continue
+		}
+		if got != tc.want {
+			t.Errorf("ParseAmountCents(%q) = %d, want %d", tc.in, got, tc.want)
+		}
+	}
+
+	bad := []string{"", "abc", "12.345", "-5.00", "0", "0.00", "12.3.4", "."}
+	for _, in := range bad {
+		if _, err := ParseAmountCents(in); err == nil {
+			t.Errorf("ParseAmountCents(%q) expected error, got nil", in)
+		}
+	}
+}
diff --git a/internal/storage/lookup.go b/internal/storage/lookup.go
new file mode 100644
index 0000000..27256b1
--- /dev/null
+++ b/internal/storage/lookup.go
@@ -0,0 +1,70 @@
+package storage
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ListCategories returns all categories ordered by label.
+func (s *Store) ListCategories() ([]Lookup, error) { return s.listLookup("categories") }
+
+// ListPeople returns all people ("Who") ordered by label.
+func (s *Store) ListPeople() ([]Lookup, error) { return s.listLookup("people") }
+
+// AddCategory inserts a new category label and returns its id.
+func (s *Store) AddCategory(label string) (int64, error) { return s.addLookup("categories", label) }
+
+// AddPerson inserts a new person label and returns its id.
+func (s *Store) AddPerson(label string) (int64, error) { return s.addLookup("people", label) }
+
+// RenameCategory updates a category's label (the change propagates to every
+// receipt referencing it, since receipts hold the id, not the text).
+func (s *Store) RenameCategory(id int64, label string) error {
+	return s.renameLookup("categories", id, label)
+}
+
+// RenamePerson updates a person's label.
+func (s *Store) RenamePerson(id int64, label string) error {
+	return s.renameLookup("people", id, label)
+}
+
+func (s *Store) listLookup(table string) ([]Lookup, error) {
+	rows, err := s.db.Query(`SELECT id, label FROM ` + table + ` ORDER BY label COLLATE NOCASE`)
+	if err != nil {
+		return nil, fmt.Errorf("list %s: %w", table, err)
+	}
+	defer rows.Close()
+
+	var out []Lookup
+	for rows.Next() {
+		var l Lookup
+		if err := rows.Scan(&l.ID, &l.Label); err != nil {
+			return nil, fmt.Errorf("scan %s: %w", table, err)
+		}
+		out = append(out, l)
+	}
+	return out, rows.Err()
+}
+
+func (s *Store) addLookup(table, label string) (int64, error) {
+	label = strings.TrimSpace(label)
+	if label == "" {
+		return 0, fmt.Errorf("label cannot be empty")
+	}
+	res, err := s.db.Exec(`INSERT INTO `+table+`(label) VALUES (?)`, label)
+	if err != nil {
+		return 0, fmt.Errorf("add %s: %w", table, err)
+	}
+	return res.LastInsertId()
+}
+
+func (s *Store) renameLookup(table string, id int64, label string) error {
+	label = strings.TrimSpace(label)
+	if label == "" {
+		return fmt.Errorf("label cannot be empty")
+	}
+	if _, err := s.db.Exec(`UPDATE `+table+` SET label = ? WHERE id = ?`, label, id); err != nil {
+		return fmt.Errorf("rename %s: %w", table, err)
+	}
+	return nil
+}
diff --git a/internal/storage/snapshot.go b/internal/storage/snapshot.go
new file mode 100644
index 0000000..d6b4d0c
--- /dev/null
+++ b/internal/storage/snapshot.go
@@ -0,0 +1,41 @@
+package storage
+
+import (
+	"database/sql"
+	"fmt"
+	"strings"
+)
+
+// SnapshotTo writes a consistent point-in-time copy of the database to destPath
+// using SQLite's VACUUM INTO (never touching/locking the live file). When
+// includeBlobs is false, the image_data blobs are stripped from the copy,
+// leaving only metadata — which is ~99% smaller.
+//
+// destPath must not already exist (VACUUM INTO requires this).
+func (s *Store) SnapshotTo(destPath string, includeBlobs bool) error {
+	if _, err := s.db.Exec(`VACUUM INTO '` + escapeSQLiteString(destPath) + `'`); err != nil {
+		return fmt.Errorf("vacuum into snapshot: %w", err)
+	}
+	if includeBlobs {
+		return nil
+	}
+
+	// Strip blobs from the copy only. image_data is NOT NULL, so use an empty blob.
+	snap, err := sql.Open("sqlite", destPath)
+	if err != nil {
+		return fmt.Errorf("open snapshot: %w", err)
+	}
+	defer snap.Close()
+	if _, err := snap.Exec(`UPDATE receipts SET image_data = X''`); err != nil {
+		return fmt.Errorf("strip blobs: %w", err)
+	}
+	if _, err := snap.Exec(`VACUUM`); err != nil {
+		return fmt.Errorf("vacuum stripped snapshot: %w", err)
+	}
+	return nil
+}
+
+// escapeSQLiteString escapes a string for use inside single quotes in SQL.
+func escapeSQLiteString(s string) string {
+	return strings.ReplaceAll(s, "'", "''")
+}
diff --git a/internal/storage/snapshot_test.go b/internal/storage/snapshot_test.go
new file mode 100644
index 0000000..fb3f55c
--- /dev/null
+++ b/internal/storage/snapshot_test.go
@@ -0,0 +1,71 @@
+package storage
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestSnapshotWithBlobs(t *testing.T) {
+	s := newTestStore(t)
+	r := sampleReceipt(firstCategoryID(t, s))
+	if err := s.Insert(r); err != nil {
+		t.Fatal(err)
+	}
+
+	dest := filepath.Join(t.TempDir(), "snap.db")
+	if err := s.SnapshotTo(dest, true); err != nil {
+		t.Fatalf("SnapshotTo: %v", err)
+	}
+
+	snap, err := Open(dest)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer snap.Close()
+
+	got, err := snap.Get(r.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got.ImageData) != string(r.ImageData) {
+		t.Errorf("blob not preserved: got %q", got.ImageData)
+	}
+}
+
+func TestSnapshotWithoutBlobs(t *testing.T) {
+	s := newTestStore(t)
+	r := sampleReceipt(firstCategoryID(t, s))
+	if err := s.Insert(r); err != nil {
+		t.Fatal(err)
+	}
+
+	dest := filepath.Join(t.TempDir(), "snap-noblob.db")
+	if err := s.SnapshotTo(dest, false); err != nil {
+		t.Fatalf("SnapshotTo: %v", err)
+	}
+
+	snap, err := Open(dest)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer snap.Close()
+
+	// Metadata row survives, but the blob is stripped.
+	n, err := snap.CountActive()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 1 {
+		t.Errorf("CountActive = %d, want 1 (metadata should survive)", n)
+	}
+	got, err := snap.Get(r.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got.ImageData) != 0 {
+		t.Errorf("blob not stripped: got %d bytes", len(got.ImageData))
+	}
+	if got.AmountCents != r.AmountCents {
+		t.Errorf("metadata lost: amount = %d, want %d", got.AmountCents, r.AmountCents)
+	}
+}
diff --git a/internal/storage/storage.go b/internal/storage/storage.go
new file mode 100644
index 0000000..a52bd88
--- /dev/null
+++ b/internal/storage/storage.go
@@ -0,0 +1,179 @@
+// Package storage is the SQLite persistence layer for receipts.
+package storage
+
+import (
+	"database/sql"
+	"fmt"
+	"strings"
+	"time"
+
+	_ "modernc.org/sqlite"
+
+	"maisym.com/hsa/internal/receipt"
+)
+
+// Store wraps the SQLite database.
+type Store struct {
+	db *sql.DB
+}
+
+// Lookup is an editable label referenced by receipts via foreign key.
+type Lookup struct {
+	ID    int64
+	Label string
+}
+
+// seedCategories are inserted on first open. They can be renamed (and more added)
+// from the manage portal; receipts reference them by id, so renames propagate.
+var seedCategories = []string{"Medical", "Dental", "Vision", "Pharmacy", "Other"}
+
+const schema = `
+CREATE TABLE IF NOT EXISTS categories (
+    id    INTEGER PRIMARY KEY AUTOINCREMENT,
+    label TEXT NOT NULL UNIQUE
+);
+CREATE TABLE IF NOT EXISTS people (
+    id    INTEGER PRIMARY KEY AUTOINCREMENT,
+    label TEXT NOT NULL UNIQUE
+);
+CREATE TABLE IF NOT EXISTS receipts (
+    id                TEXT PRIMARY KEY,
+    uploaded_by       TEXT NOT NULL,
+    uploaded_at       TEXT NOT NULL,
+    receipt_date      TEXT NOT NULL,
+    amount_cents      INTEGER NOT NULL,
+    category_id       INTEGER NOT NULL REFERENCES categories(id),
+    person_id         INTEGER REFERENCES people(id),
+    file_path         TEXT NOT NULL,
+    image_data        BLOB NOT NULL,
+    file_size_bytes   INTEGER NOT NULL,
+    original_filename TEXT NOT NULL,
+    mime_type         TEXT NOT NULL,
+    deleted_at        TEXT
+);
+CREATE INDEX IF NOT EXISTS idx_receipts_active ON receipts(deleted_at);
+`
+
+// Open opens (creating if needed) the SQLite database at path, applies the schema,
+// and seeds the category list on first creation.
+func Open(path string) (*Store, error) {
+	db, err := sql.Open("sqlite", path)
+	if err != nil {
+		return nil, fmt.Errorf("open sqlite: %w", err)
+	}
+	if _, err := db.Exec(`PRAGMA journal_mode=WAL; PRAGMA foreign_keys=ON; PRAGMA busy_timeout=5000;`); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("set pragmas: %w", err)
+	}
+	if _, err := db.Exec(schema); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("apply schema: %w", err)
+	}
+	for _, label := range seedCategories {
+		if _, err := db.Exec(`INSERT OR IGNORE INTO categories(label) VALUES (?)`, label); err != nil {
+			db.Close()
+			return nil, fmt.Errorf("seed categories: %w", err)
+		}
+	}
+	return &Store{db: db}, nil
+}
+
+func (s *Store) Close() error { return s.db.Close() }
+
+// Seed inserts the given category and person labels if they are not already
+// present (INSERT OR IGNORE), so renames made in the manage portal are preserved
+// across restarts. Called on startup from the config catalog.
+func (s *Store) Seed(categories, people []string) error {
+	insert := func(table string, labels []string) error {
+		for _, label := range labels {
+			label = strings.TrimSpace(label)
+			if label == "" {
+				continue
+			}
+			if _, err := s.db.Exec(`INSERT OR IGNORE INTO `+table+`(label) VALUES (?)`, label); err != nil {
+				return fmt.Errorf("seed %s: %w", table, err)
+			}
+		}
+		return nil
+	}
+	if err := insert("categories", categories); err != nil {
+		return err
+	}
+	return insert("people", people)
+}
+
+const rfc3339 = time.RFC3339
+
+// Insert stores a receipt (metadata + image blob) in a single statement.
+func (s *Store) Insert(r receipt.Receipt) error {
+	var personID any
+	if r.PersonID != nil {
+		personID = *r.PersonID
+	}
+	_, err := s.db.Exec(
+		`INSERT INTO receipts
+		   (id, uploaded_by, uploaded_at, receipt_date, amount_cents, category_id, person_id,
+		    file_path, image_data, file_size_bytes, original_filename, mime_type)
+		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+		r.ID, r.UploadedBy, r.UploadedAt.UTC().Format(rfc3339),
+		r.ReceiptDate.UTC().Format(rfc3339), r.AmountCents, r.CategoryID, personID,
+		r.FilePath, r.ImageData, r.FileSizeBytes, r.OriginalFilename, r.MimeType,
+	)
+	if err != nil {
+		return fmt.Errorf("insert receipt: %w", err)
+	}
+	return nil
+}
+
+// Get returns the receipt with the given id (including soft-deleted rows).
+func (s *Store) Get(id string) (receipt.Receipt, error) {
+	row := s.db.QueryRow(
+		`SELECT id, uploaded_by, uploaded_at, receipt_date, amount_cents, category_id, person_id,
+		        file_path, image_data, file_size_bytes, original_filename, mime_type, deleted_at
+		 FROM receipts WHERE id = ?`, id)
+
+	var r receipt.Receipt
+	var uploadedAt, receiptDate string
+	var personID sql.NullInt64
+	var deletedAt sql.NullString
+	if err := row.Scan(
+		&r.ID, &r.UploadedBy, &uploadedAt, &receiptDate, &r.AmountCents, &r.CategoryID, &personID,
+		&r.FilePath, &r.ImageData, &r.FileSizeBytes, &r.OriginalFilename, &r.MimeType, &deletedAt,
+	); err != nil {
+		return receipt.Receipt{}, fmt.Errorf("get receipt: %w", err)
+	}
+	r.UploadedAt, _ = time.Parse(rfc3339, uploadedAt)
+	r.ReceiptDate, _ = time.Parse(rfc3339, receiptDate)
+	if personID.Valid {
+		r.PersonID = &personID.Int64
+	}
+	if deletedAt.Valid {
+		if t, err := time.Parse(rfc3339, deletedAt.String); err == nil {
+			r.DeletedAt = &t
+		}
+	}
+	return r, nil
+}
+
+// SoftDelete marks a receipt deleted without removing the row or its blob.
+func (s *Store) SoftDelete(id string) error {
+	_, err := s.db.Exec(
+		`UPDATE receipts SET deleted_at = ? WHERE id = ? AND deleted_at IS NULL`,
+		time.Now().UTC().Format(rfc3339), id)
+	if err != nil {
+		return fmt.Errorf("soft delete: %w", err)
+	}
+	return nil
+}
+
+// CountActive returns the number of non-deleted receipts.
+func (s *Store) CountActive() (int, error) {
+	var n int
+	if err := s.db.QueryRow(`SELECT COUNT(*) FROM receipts WHERE deleted_at IS NULL`).Scan(&n); err != nil {
+		return 0, fmt.Errorf("count active: %w", err)
+	}
+	return n, nil
+}
+
+// DB exposes the underlying handle for the export snapshot.
+func (s *Store) DB() *sql.DB { return s.db }
diff --git a/internal/storage/storage_test.go b/internal/storage/storage_test.go
new file mode 100644
index 0000000..62f2e4e
--- /dev/null
+++ b/internal/storage/storage_test.go
@@ -0,0 +1,175 @@
+package storage
+
+import (
+	"path/filepath"
+	"testing"
+	"time"
+
+	"maisym.com/hsa/internal/receipt"
+)
+
+func newTestStore(t *testing.T) *Store {
+	t.Helper()
+	dbPath := filepath.Join(t.TempDir(), "test.db")
+	s, err := Open(dbPath)
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+	t.Cleanup(func() { s.Close() })
+	return s
+}
+
+func sampleReceipt(categoryID int64) receipt.Receipt {
+	return receipt.Receipt{
+		ID:               "11111111-1111-1111-1111-111111111111",
+		UploadedBy:       "jm@example.com",
+		UploadedAt:       time.Now().UTC().Truncate(time.Second),
+		ReceiptDate:      time.Date(2026, 6, 1, 0, 0, 0, 0, time.UTC),
+		AmountCents:      1234,
+		CategoryID:       categoryID,
+		FilePath:         "ab/abcd.jpg",
+		ImageData:        []byte("fake-image-bytes"),
+		FileSizeBytes:    16,
+		OriginalFilename: "receipt.jpg",
+		MimeType:         "image/jpeg",
+	}
+}
+
+// firstCategoryID returns the id of a seeded category for use in tests.
+func firstCategoryID(t *testing.T, s *Store) int64 {
+	t.Helper()
+	cats, err := s.ListCategories()
+	if err != nil || len(cats) == 0 {
+		t.Fatalf("ListCategories: %v (len %d)", err, len(cats))
+	}
+	return cats[0].ID
+}
+
+func TestInsertAndCount(t *testing.T) {
+	s := newTestStore(t)
+	if err := s.Insert(sampleReceipt(firstCategoryID(t, s))); err != nil {
+		t.Fatalf("Insert: %v", err)
+	}
+
+	n, err := s.CountActive()
+	if err != nil {
+		t.Fatalf("CountActive: %v", err)
+	}
+	if n != 1 {
+		t.Errorf("CountActive = %d, want 1", n)
+	}
+}
+
+func TestInsertPreservesBlobAndFields(t *testing.T) {
+	s := newTestStore(t)
+	r := sampleReceipt(firstCategoryID(t, s))
+	if err := s.Insert(r); err != nil {
+		t.Fatalf("Insert: %v", err)
+	}
+
+	got, err := s.Get(r.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if got.AmountCents != r.AmountCents {
+		t.Errorf("AmountCents = %d, want %d", got.AmountCents, r.AmountCents)
+	}
+	if string(got.ImageData) != string(r.ImageData) {
+		t.Errorf("ImageData = %q, want %q", got.ImageData, r.ImageData)
+	}
+	if got.CategoryID != r.CategoryID || got.OriginalFilename != r.OriginalFilename {
+		t.Errorf("field mismatch: %+v", got)
+	}
+}
+
+func TestInsertWithPerson(t *testing.T) {
+	s := newTestStore(t)
+	pid, err := s.AddPerson("John")
+	if err != nil {
+		t.Fatal(err)
+	}
+	r := sampleReceipt(firstCategoryID(t, s))
+	r.PersonID = &pid
+	if err := s.Insert(r); err != nil {
+		t.Fatalf("Insert: %v", err)
+	}
+	got, err := s.Get(r.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.PersonID == nil || *got.PersonID != pid {
+		t.Errorf("PersonID = %v, want %d", got.PersonID, pid)
+	}
+}
+
+func TestInsertRejectsUnknownCategoryFK(t *testing.T) {
+	s := newTestStore(t)
+	r := sampleReceipt(99999) // no such category
+	if err := s.Insert(r); err == nil {
+		t.Error("expected FK violation for unknown category_id, got nil")
+	}
+}
+
+func TestRenameCategoryPropagatesViaID(t *testing.T) {
+	s := newTestStore(t)
+	cid := firstCategoryID(t, s)
+	r := sampleReceipt(cid)
+	if err := s.Insert(r); err != nil {
+		t.Fatal(err)
+	}
+	if err := s.RenameCategory(cid, "Medical (fixed)"); err != nil {
+		t.Fatal(err)
+	}
+	// The receipt still points at the same id; the label change is automatic.
+	got, _ := s.Get(r.ID)
+	if got.CategoryID != cid {
+		t.Errorf("CategoryID changed after rename: %d", got.CategoryID)
+	}
+	cats, _ := s.ListCategories()
+	var found bool
+	for _, c := range cats {
+		if c.ID == cid && c.Label == "Medical (fixed)" {
+			found = true
+		}
+	}
+	if !found {
+		t.Errorf("rename not reflected in ListCategories: %+v", cats)
+	}
+}
+
+func TestSoftDeleteHidesFromCount(t *testing.T) {
+	s := newTestStore(t)
+	r := sampleReceipt(firstCategoryID(t, s))
+	if err := s.Insert(r); err != nil {
+		t.Fatalf("Insert: %v", err)
+	}
+	if err := s.SoftDelete(r.ID); err != nil {
+		t.Fatalf("SoftDelete: %v", err)
+	}
+
+	n, err := s.CountActive()
+	if err != nil {
+		t.Fatalf("CountActive: %v", err)
+	}
+	if n != 0 {
+		t.Errorf("CountActive after soft delete = %d, want 0", n)
+	}
+}
+
+func TestSeededCategories(t *testing.T) {
+	s := newTestStore(t)
+	cats, err := s.ListCategories()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(cats) != 5 {
+		t.Errorf("seeded categories = %d, want 5", len(cats))
+	}
+	people, err := s.ListPeople()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(people) != 0 {
+		t.Errorf("people should start empty, got %d", len(people))
+	}
+}
diff --git a/internal/web/export.go b/internal/web/export.go
new file mode 100644
index 0000000..b617087
--- /dev/null
+++ b/internal/web/export.go
@@ -0,0 +1,54 @@
+package web
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+func (s *Server) handleExportPage(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := exportPage.ExecuteTemplate(w, "base", nil); err != nil {
+		s.serverError(w, "render export page", err)
+	}
+}
+
+func (s *Server) handleExportDB(w http.ResponseWriter, r *http.Request) {
+	includeBlobs := r.URL.Query().Get("blobs") != "false" // default: include
+
+	// Snapshot to a fresh temp path (VACUUM INTO requires the file not exist).
+	tmpDir, err := os.MkdirTemp("", "hsa-export-")
+	if err != nil {
+		s.serverError(w, "export tempdir", err)
+		return
+	}
+	defer os.RemoveAll(tmpDir)
+	snapPath := filepath.Join(tmpDir, "snapshot.db")
+
+	if err := s.store.SnapshotTo(snapPath, includeBlobs); err != nil {
+		s.serverError(w, "export snapshot", err)
+		return
+	}
+
+	f, err := os.Open(snapPath)
+	if err != nil {
+		s.serverError(w, "open snapshot", err)
+		return
+	}
+	defer f.Close()
+
+	suffix := ""
+	if !includeBlobs {
+		suffix = "-metadata"
+	}
+	filename := fmt.Sprintf("hsa-export-%s%s.db", time.Now().Format(dateLayout), suffix)
+
+	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%q", filename))
+	if fi, err := f.Stat(); err == nil {
+		w.Header().Set("Content-Length", fmt.Sprintf("%d", fi.Size()))
+	}
+	http.ServeContent(w, r, filename, time.Now(), f)
+}
diff --git a/internal/web/manage.go b/internal/web/manage.go
new file mode 100644
index 0000000..e0ddedd
--- /dev/null
+++ b/internal/web/manage.go
@@ -0,0 +1,85 @@
+package web
+
+import (
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"maisym.com/hsa/internal/storage"
+)
+
+type manageView struct {
+	Categories []storage.Lookup
+	People     []storage.Lookup
+	Error      string
+}
+
+func (s *Server) handleManage(w http.ResponseWriter, r *http.Request) {
+	cats, people, err := s.lookups()
+	if err != nil {
+		s.serverError(w, "load lookups", err)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_ = managePage.ExecuteTemplate(w, "base", manageView{
+		Categories: cats,
+		People:     people,
+		Error:      r.URL.Query().Get("error"),
+	})
+}
+
+func (s *Server) handleAddCategory(w http.ResponseWriter, r *http.Request) {
+	s.addLookup(w, r, s.store.AddCategory)
+}
+
+func (s *Server) handleAddPerson(w http.ResponseWriter, r *http.Request) {
+	s.addLookup(w, r, s.store.AddPerson)
+}
+
+func (s *Server) handleRenameCategory(w http.ResponseWriter, r *http.Request) {
+	s.renameLookup(w, r, s.store.RenameCategory)
+}
+
+func (s *Server) handleRenamePerson(w http.ResponseWriter, r *http.Request) {
+	s.renameLookup(w, r, s.store.RenamePerson)
+}
+
+func (s *Server) addLookup(w http.ResponseWriter, r *http.Request, add func(string) (int64, error)) {
+	label := strings.TrimSpace(r.FormValue("label"))
+	if label == "" {
+		redirectManage(w, r, "Label cannot be empty.")
+		return
+	}
+	if _, err := add(label); err != nil {
+		redirectManage(w, r, "Could not add — maybe that label already exists.")
+		return
+	}
+	redirectManage(w, r, "")
+}
+
+func (s *Server) renameLookup(w http.ResponseWriter, r *http.Request, rename func(int64, string) error) {
+	id, err := strconv.ParseInt(strings.TrimSpace(r.FormValue("id")), 10, 64)
+	if err != nil {
+		redirectManage(w, r, "Invalid id.")
+		return
+	}
+	label := strings.TrimSpace(r.FormValue("label"))
+	if label == "" {
+		redirectManage(w, r, "Label cannot be empty.")
+		return
+	}
+	if err := rename(id, label); err != nil {
+		redirectManage(w, r, "Could not rename — maybe that label already exists.")
+		return
+	}
+	redirectManage(w, r, "")
+}
+
+func redirectManage(w http.ResponseWriter, r *http.Request, errMsg string) {
+	target := "/manage"
+	if errMsg != "" {
+		target += "?error=" + url.QueryEscape(errMsg)
+	}
+	http.Redirect(w, r, target, http.StatusSeeOther)
+}
diff --git a/internal/web/manage_test.go b/internal/web/manage_test.go
new file mode 100644
index 0000000..8f7ff53
--- /dev/null
+++ b/internal/web/manage_test.go
@@ -0,0 +1,110 @@
+package web
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+func postForm(t *testing.T, s *Server, path string, form url.Values) *httptest.ResponseRecorder {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodPost, path, strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+	return rec
+}
+
+func TestManage_AddAndRenamePerson(t *testing.T) {
+	s := testServerWithStore(t)
+
+	// Add "johnn" (with the typo).
+	rec := postForm(t, s, "/manage/people", url.Values{"label": {"johnn"}})
+	if rec.Code != http.StatusSeeOther {
+		t.Fatalf("add person status = %d, want 303", rec.Code)
+	}
+	people, _ := s.store.ListPeople()
+	if len(people) != 1 || people[0].Label != "johnn" {
+		t.Fatalf("after add: %+v", people)
+	}
+	id := people[0].ID
+
+	// Rename to fix the typo — same id.
+	rec = postForm(t, s, "/manage/people/rename",
+		url.Values{"id": {strconv.FormatInt(id, 10)}, "label": {"John"}})
+	if rec.Code != http.StatusSeeOther {
+		t.Fatalf("rename status = %d, want 303", rec.Code)
+	}
+	people, _ = s.store.ListPeople()
+	if len(people) != 1 || people[0].ID != id || people[0].Label != "John" {
+		t.Errorf("after rename: %+v (id should be unchanged)", people)
+	}
+}
+
+func TestManage_AddCategory(t *testing.T) {
+	s := testServerWithStore(t)
+	postForm(t, s, "/manage/categories", url.Values{"label": {"Chiropractic"}})
+	cats, _ := s.store.ListCategories()
+	if len(cats) != 6 { // 5 seeded + 1
+		t.Errorf("categories = %d, want 6", len(cats))
+	}
+}
+
+func TestManage_EmptyLabelRejected(t *testing.T) {
+	s := testServerWithStore(t)
+	rec := postForm(t, s, "/manage/people", url.Values{"label": {"   "}})
+	loc := rec.Header().Get("Location")
+	if !strings.Contains(loc, "error=") {
+		t.Errorf("expected error redirect, got %q", loc)
+	}
+	people, _ := s.store.ListPeople()
+	if len(people) != 0 {
+		t.Errorf("empty label should not create a person, got %d", len(people))
+	}
+}
+
+func TestManage_PageListsCategories(t *testing.T) {
+	s := testServerWithStore(t)
+	req := httptest.NewRequest(http.MethodGet, "/manage", nil)
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+	body := rec.Body.String()
+	for _, want := range []string{"Medical", "Categories", "Who"} {
+		if !strings.Contains(body, want) {
+			t.Errorf("manage page missing %q", want)
+		}
+	}
+}
+
+func TestUpload_WithWho_StoresPersonID(t *testing.T) {
+	s := testServerWithStore(t)
+	pid, err := s.store.AddPerson("John")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	body, ct := multipartUpload(t,
+		map[string]string{
+			"amount": "20.00", "receipt_date": "2026-06-01",
+			"category_id": aCategoryID(t, s), "person_id": strconv.FormatInt(pid, 10),
+		},
+		"receipt", "r.png", fakePNG())
+	req := httptest.NewRequest(http.MethodPost, "/upload", body)
+	req.Header.Set("Content-Type", ct)
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK || !strings.Contains(rec.Body.String(), "John") {
+		t.Errorf("expected confirmation mentioning John; status=%d body=%s", rec.Code, rec.Body.String())
+	}
+}
diff --git a/internal/web/middleware.go b/internal/web/middleware.go
new file mode 100644
index 0000000..feb6faa
--- /dev/null
+++ b/internal/web/middleware.go
@@ -0,0 +1,63 @@
+package web
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"maisym.com/hsa/internal/auth"
+)
+
+type ctxKey int
+
+const sessionKey ctxKey = 0
+
+// requireAuth rejects requests without a valid session cookie by redirecting to /login.
+// On success the decoded session is placed in the request context.
+func (s *Server) requireAuth(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		c, err := r.Cookie(sessionCookie)
+		if err != nil {
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+		sess, err := auth.DecodeSession(c.Value, s.cfg.SessionKey)
+		if err != nil {
+			s.clearCookie(w, sessionCookie)
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+		ctx := context.WithValue(r.Context(), sessionKey, sess)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+// sessionFrom returns the session stored in the context by requireAuth.
+func sessionFrom(ctx context.Context) auth.Session {
+	sess, _ := ctx.Value(sessionKey).(auth.Session)
+	return sess
+}
+
+func (s *Server) setCookie(w http.ResponseWriter, name, value string, ttl time.Duration) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     name,
+		Value:    value,
+		Path:     "/",
+		MaxAge:   int(ttl.Seconds()),
+		HttpOnly: true,
+		Secure:   s.cfg.SecureCookies,
+		SameSite: http.SameSiteLaxMode,
+	})
+}
+
+func (s *Server) clearCookie(w http.ResponseWriter, name string) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     name,
+		Value:    "",
+		Path:     "/",
+		MaxAge:   -1,
+		HttpOnly: true,
+		Secure:   s.cfg.SecureCookies,
+		SameSite: http.SameSiteLaxMode,
+	})
+}
diff --git a/internal/web/scan.go b/internal/web/scan.go
new file mode 100644
index 0000000..d54f50c
--- /dev/null
+++ b/internal/web/scan.go
@@ -0,0 +1,105 @@
+package web
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"maisym.com/hsa/internal/storage"
+)
+
+// classifyResponse is the JSON returned to the upload page to pre-fill the form.
+// IDs map the classifier's label suggestions onto the live lookup rows; they are
+// null when the classifier returned nothing or the label has no matching row.
+type classifyResponse struct {
+	Amount     *string `json:"amount"`
+	Date       *string `json:"date"`
+	CategoryID *int64  `json:"category_id"`
+	PersonID   *int64  `json:"person_id"`
+
+	Category string `json:"category"` // label, for display
+	Person   string `json:"person"`   // label, for display
+
+	RawName   string `json:"raw_name"`
+	RawDate   string `json:"raw_date"`
+	RawAmount string `json:"raw_amount"`
+}
+
+// handleClassify accepts an uploaded receipt image and returns suggested form
+// values from the AI classifier. It mutates no state — the user still reviews and
+// submits via POST /upload.
+func (s *Server) handleClassify(w http.ResponseWriter, r *http.Request) {
+	if s.classifier == nil {
+		http.Error(w, "classification not configured", http.StatusServiceUnavailable)
+		return
+	}
+
+	r.Body = http.MaxBytesReader(w, r.Body, s.cfg.MaxUploadBytes)
+	if err := r.ParseMultipartForm(10 << 20); err != nil {
+		http.Error(w, "upload too large or malformed", http.StatusBadRequest)
+		return
+	}
+
+	file, _, err := r.FormFile("receipt")
+	if err != nil {
+		http.Error(w, "attach a receipt image or PDF", http.StatusBadRequest)
+		return
+	}
+	defer file.Close()
+	data, err := io.ReadAll(file)
+	if err != nil {
+		http.Error(w, "could not read the uploaded file", http.StatusBadRequest)
+		return
+	}
+	mimeType := detectMime(data)
+	if !allowedMime(mimeType) {
+		http.Error(w, "only images and PDFs are allowed", http.StatusUnsupportedMediaType)
+		return
+	}
+
+	sug, err := s.classifier.Classify(r.Context(), time.Now(), data, mimeType)
+	if err != nil {
+		s.serverError(w, "classify receipt", err)
+		return
+	}
+
+	cats, people, err := s.lookups()
+	if err != nil {
+		s.serverError(w, "load lookups", err)
+		return
+	}
+
+	out := classifyResponse{
+		Amount:    sug.Amount,
+		Date:      sug.Date,
+		Category:  sug.Category,
+		RawName:   sug.RawName,
+		RawDate:   sug.RawDate,
+		RawAmount: sug.RawAmount,
+	}
+	if id, ok := idForLabel(sug.Category, cats); ok {
+		out.CategoryID = &id
+	}
+	if sug.Person != nil {
+		if id, ok := idForLabel(*sug.Person, people); ok {
+			out.PersonID = &id
+			out.Person = *sug.Person
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(out)
+}
+
+// idForLabel finds a lookup row by case-insensitive label match.
+func idForLabel(label string, set []storage.Lookup) (int64, bool) {
+	label = strings.TrimSpace(label)
+	for _, l := range set {
+		if strings.EqualFold(l.Label, label) {
+			return l.ID, true
+		}
+	}
+	return 0, false
+}
diff --git a/internal/web/static/style.css b/internal/web/static/style.css
new file mode 100644
index 0000000..d4b682a
--- /dev/null
+++ b/internal/web/static/style.css
@@ -0,0 +1,83 @@
+body {
+  font-family: system-ui, sans-serif;
+  max-width: 30rem;
+  margin: 0 auto;
+  padding: 1rem;
+  line-height: 1.5;
+}
+
+header {
+  display: flex;
+  justify-content: space-between;
+  font-size: .85rem;
+  color: #555;
+  margin-bottom: 1rem;
+}
+
+h2 { margin-top: 1.5rem; }
+
+label {
+  display: block;
+  margin: 1rem 0 .25rem;
+  font-weight: 600;
+}
+
+input, select {
+  font-size: 1.1rem;
+  width: 100%;
+  padding: .6rem;
+  box-sizing: border-box;
+}
+
+a { color: #1a73e8; }
+small { color: #555; }
+
+.err {
+  background: #fce8e6;
+  color: #a50e0e;
+  padding: .6rem;
+  border-radius: .4rem;
+  margin: .5rem 0;
+}
+
+.ok {
+  color: #137333;
+  font-weight: 600;
+  font-size: 1.3rem;
+}
+
+/* Full-width primary submit button (upload form). */
+button.primary {
+  font-size: 1.1rem;
+  width: 100%;
+  padding: .6rem;
+  margin-top: 1.5rem;
+  background: #137333;
+  color: #fff;
+  border: 0;
+  border-radius: .4rem;
+  font-weight: 600;
+}
+
+/* Links styled as buttons. */
+a.button {
+  display: block;
+  text-align: center;
+  color: #fff;
+  padding: .7rem;
+  border-radius: .4rem;
+  text-decoration: none;
+  margin: .75rem 0;
+}
+a.button.green { background: #137333; }
+a.button.blue  { background: #1a73e8; }
+
+/* Inline rename/add rows on the manage page. */
+form.row {
+  display: flex;
+  gap: .4rem;
+  margin: .3rem 0;
+}
+form.row input { flex: 1; padding: .4rem; }
+form.row button { padding: .4rem .7rem; }
+.add input { border: 1px solid #137333; }
diff --git a/internal/web/templates.go b/internal/web/templates.go
new file mode 100644
index 0000000..8a3e51f
--- /dev/null
+++ b/internal/web/templates.go
@@ -0,0 +1,25 @@
+package web
+
+import (
+	"embed"
+	"html/template"
+)
+
+//go:embed templates/*.html
+var templatesFS embed.FS
+
+//go:embed static/*
+var staticFS embed.FS
+
+// parsePage parses the shared base layout together with a single page template,
+// yielding a template set whose "base" definition renders the full document.
+func parsePage(name string) *template.Template {
+	return template.Must(template.ParseFS(templatesFS, "templates/base.html", "templates/"+name))
+}
+
+var (
+	uploadPage  = parsePage("upload.html")
+	confirmPage = parsePage("confirm.html")
+	managePage  = parsePage("manage.html")
+	exportPage  = parsePage("export.html")
+)
diff --git a/internal/web/templates/base.html b/internal/web/templates/base.html
new file mode 100644
index 0000000..6c61e33
--- /dev/null
+++ b/internal/web/templates/base.html
@@ -0,0 +1,12 @@
+{{define "base"}}<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<title>{{block "title" .}}HSA Receipt Tracker{{end}}</title>
+<link rel="stylesheet" href="/static/style.css">
+</head>
+<body>
+{{block "content" .}}{{end}}
+</body>
+</html>{{end}}
diff --git a/internal/web/templates/confirm.html b/internal/web/templates/confirm.html
new file mode 100644
index 0000000..a3fbe12
--- /dev/null
+++ b/internal/web/templates/confirm.html
@@ -0,0 +1,7 @@
+{{define "title"}}Saved{{end}}
+{{define "content"}}
+<p class="ok">✓ Receipt saved</p>
+<p>{{.Category}}{{if .Who}} · {{.Who}}{{end}} — ${{.Amount}} — {{.Date}}<br>{{.Filename}}</p>
+<a class="button green" href="/">Add another</a>
+<p style="text-align:center;margin-top:1rem"><a href="/manage">Manage</a> · <a href="/export">Export</a> · <a href="/logout">Log out</a></p>
+{{end}}
diff --git a/internal/web/templates/export.html b/internal/web/templates/export.html
new file mode 100644
index 0000000..c57d9c5
--- /dev/null
+++ b/internal/web/templates/export.html
@@ -0,0 +1,9 @@
+{{define "title"}}Export{{end}}
+{{define "content"}}
+<h1>Export database</h1>
+<a class="button blue" href="/export/db?blobs=true">Download full DB (with images)</a>
+<a class="button blue" href="/export/db?blobs=false">Download metadata only (no images)</a>
+<p><small>The full DB is a complete, self-contained snapshot — metadata and every
+receipt image in one SQLite file. Metadata-only omits the image blobs (~99% of the size).</small></p>
+<p style="text-align:center"><a href="/">Back</a></p>
+{{end}}
diff --git a/internal/web/templates/manage.html b/internal/web/templates/manage.html
new file mode 100644
index 0000000..cc0e700
--- /dev/null
+++ b/internal/web/templates/manage.html
@@ -0,0 +1,34 @@
+{{define "title"}}Manage{{end}}
+{{define "content"}}
+<p><a href="/">← Back to upload</a></p>
+<h1>Manage lists</h1>
+<p><small>Rename fixes the label everywhere it's used (receipts reference these by id). Adding a new entry creates a fresh id.</small></p>
+{{if .Error}}<div class="err">{{.Error}}</div>{{end}}
+
+<h2>Categories</h2>
+{{range .Categories}}
+<form class="row" method="post" action="/manage/categories/rename">
+  <input type="hidden" name="id" value="{{.ID}}">
+  <input type="text" name="label" value="{{.Label}}">
+  <button type="submit">Save</button>
+</form>
+{{end}}
+<form class="row add" method="post" action="/manage/categories">
+  <input type="text" name="label" placeholder="New category">
+  <button type="submit">Add</button>
+</form>
+
+<h2>Who</h2>
+{{if not .People}}<p><small>No entries yet — add one below.</small></p>{{end}}
+{{range .People}}
+<form class="row" method="post" action="/manage/people/rename">
+  <input type="hidden" name="id" value="{{.ID}}">
+  <input type="text" name="label" value="{{.Label}}">
+  <button type="submit">Save</button>
+</form>
+{{end}}
+<form class="row add" method="post" action="/manage/people">
+  <input type="text" name="label" placeholder="New person">
+  <button type="submit">Add</button>
+</form>
+{{end}}
diff --git a/internal/web/templates/upload.html b/internal/web/templates/upload.html
new file mode 100644
index 0000000..a5630bb
--- /dev/null
+++ b/internal/web/templates/upload.html
@@ -0,0 +1,29 @@
+{{define "title"}}Add receipt{{end}}
+{{define "content"}}
+<header>
+  <span>{{.Subject}}</span>
+  <span><a href="/manage">Manage</a> · <a href="/export">Export</a> · <a href="/logout">Log out</a></span>
+</header>
+<h1>Add receipt</h1>
+{{range .Errors}}<div class="err">{{.}}</div>{{end}}
+<form method="post" action="/upload" enctype="multipart/form-data">
+  <label for="receipt">Receipt photo or PDF</label>
+  <input id="receipt" type="file" name="receipt" accept="image/*,application/pdf" capture="environment" required>
+  <label for="amount">Amount ($)</label>
+  <input id="amount" type="number" name="amount" step="0.01" min="0.01" inputmode="decimal" value="{{.Amount}}" required>
+  <label for="receipt_date">Date on receipt</label>
+  <input id="receipt_date" type="date" name="receipt_date" value="{{.Date}}" required>
+  <label for="category_id">Category</label>
+  <select id="category_id" name="category_id">
+    {{$sc := .CategoryID}}
+    {{range .Categories}}<option value="{{.ID}}" {{if eq (printf "%d" .ID) $sc}}selected{{end}}>{{.Label}}</option>{{end}}
+  </select>
+  <label for="person_id">Who</label>
+  <select id="person_id" name="person_id">
+    {{$sp := .PersonID}}
+    <option value="">—</option>
+    {{range .People}}<option value="{{.ID}}" {{if eq (printf "%d" .ID) $sp}}selected{{end}}>{{.Label}}</option>{{end}}
+  </select>
+  <button type="submit" class="primary">Submit</button>
+</form>
+{{end}}
diff --git a/internal/web/upload.go b/internal/web/upload.go
new file mode 100644
index 0000000..16f9ef1
--- /dev/null
+++ b/internal/web/upload.go
@@ -0,0 +1,259 @@
+package web
+
+import (
+	"crypto/rand"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"maisym.com/hsa/internal/receipt"
+	"maisym.com/hsa/internal/storage"
+)
+
+const dateLayout = "2006-01-02"
+
+type formView struct {
+	Subject    string
+	Categories []storage.Lookup
+	People     []storage.Lookup
+	Amount     string
+	Date       string
+	CategoryID string
+	PersonID   string
+	Errors     []string
+}
+
+func (s *Server) handleUploadForm(w http.ResponseWriter, r *http.Request) {
+	sess := sessionFrom(r.Context())
+	cats, people, err := s.lookups()
+	if err != nil {
+		s.serverError(w, "load lookups", err)
+		return
+	}
+	s.renderForm(w, formView{
+		Subject:    sess.Subject,
+		Categories: cats,
+		People:     people,
+		Date:       time.Now().Format(dateLayout),
+	})
+}
+
+func (s *Server) lookups() (cats, people []storage.Lookup, err error) {
+	cats, err = s.store.ListCategories()
+	if err != nil {
+		return nil, nil, err
+	}
+	people, err = s.store.ListPeople()
+	if err != nil {
+		return nil, nil, err
+	}
+	return cats, people, nil
+}
+
+func (s *Server) renderForm(w http.ResponseWriter, v formView) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := uploadPage.ExecuteTemplate(w, "base", v); err != nil {
+		s.serverError(w, "render form", err)
+	}
+}
+
+func (s *Server) handleUpload(w http.ResponseWriter, r *http.Request) {
+	sess := sessionFrom(r.Context())
+	cats, people, err := s.lookups()
+	if err != nil {
+		s.serverError(w, "load lookups", err)
+		return
+	}
+
+	r.Body = http.MaxBytesReader(w, r.Body, s.cfg.MaxUploadBytes)
+	if err := r.ParseMultipartForm(10 << 20); err != nil {
+		s.renderForm(w, formView{
+			Subject: sess.Subject, Categories: cats, People: people,
+			Errors: []string{"Upload too large or malformed."},
+		})
+		return
+	}
+
+	amountStr := strings.TrimSpace(r.FormValue("amount"))
+	dateStr := strings.TrimSpace(r.FormValue("receipt_date"))
+	categoryStr := strings.TrimSpace(r.FormValue("category_id"))
+	personStr := strings.TrimSpace(r.FormValue("person_id"))
+
+	view := formView{
+		Subject: sess.Subject, Categories: cats, People: people,
+		Amount: amountStr, Date: dateStr, CategoryID: categoryStr, PersonID: personStr,
+	}
+
+	var errs []string
+	amountCents, err := receipt.ParseAmountCents(amountStr)
+	if err != nil {
+		errs = append(errs, "Enter a valid amount, e.g. 12.34")
+	}
+	receiptDate, err := time.Parse(dateLayout, dateStr)
+	if err != nil {
+		errs = append(errs, "Enter a valid date.")
+	}
+
+	categoryID, ok := parseLookupID(categoryStr, cats)
+	if !ok {
+		errs = append(errs, "Choose a category.")
+	}
+
+	var personID *int64
+	if personStr != "" {
+		pid, ok := parseLookupID(personStr, people)
+		if !ok {
+			errs = append(errs, "Choose a valid \"Who\" or leave it blank.")
+		} else {
+			personID = &pid
+		}
+	}
+
+	file, header, err := r.FormFile("receipt")
+	if err != nil {
+		errs = append(errs, "Attach a receipt photo or PDF.")
+	}
+	var data []byte
+	if file != nil {
+		defer file.Close()
+		data, err = io.ReadAll(file)
+		if err != nil {
+			errs = append(errs, "Could not read the uploaded file.")
+		}
+	}
+
+	mimeType := ""
+	if len(data) > 0 {
+		mimeType = detectMime(data)
+		if !allowedMime(mimeType) {
+			errs = append(errs, "Only images and PDFs are allowed.")
+		}
+	}
+
+	if len(errs) > 0 {
+		view.Errors = errs
+		s.renderForm(w, view)
+		return
+	}
+
+	// Dual-write: file on disk (UUID name) + blob in DB.
+	id := newID()
+	ext := extFor(header.Filename, mimeType)
+	relPath := id + ext
+	if err := s.saveFile(relPath, data); err != nil {
+		s.serverError(w, "save file", err)
+		return
+	}
+
+	rec := receipt.Receipt{
+		ID:               id,
+		UploadedBy:       sess.Subject,
+		UploadedAt:       time.Now().UTC(),
+		ReceiptDate:      receiptDate,
+		AmountCents:      amountCents,
+		CategoryID:       categoryID,
+		PersonID:         personID,
+		FilePath:         relPath,
+		ImageData:        data,
+		FileSizeBytes:    int64(len(data)),
+		OriginalFilename: header.Filename,
+		MimeType:         mimeType,
+	}
+	if err := s.store.Insert(rec); err != nil {
+		s.serverError(w, "insert receipt", err)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_ = confirmPage.ExecuteTemplate(w, "base", map[string]string{
+		"Category": labelFor(categoryID, cats),
+		"Who":      whoLabel(personID, people),
+		"Amount":   fmt.Sprintf("%d.%02d", amountCents/100, amountCents%100),
+		"Date":     dateStr,
+		"Filename": header.Filename,
+	})
+}
+
+// parseLookupID parses s as an int64 and confirms it exists in the given set.
+func parseLookupID(s string, set []storage.Lookup) (int64, bool) {
+	id, err := strconv.ParseInt(s, 10, 64)
+	if err != nil {
+		return 0, false
+	}
+	for _, l := range set {
+		if l.ID == id {
+			return id, true
+		}
+	}
+	return 0, false
+}
+
+func labelFor(id int64, set []storage.Lookup) string {
+	for _, l := range set {
+		if l.ID == id {
+			return l.Label
+		}
+	}
+	return ""
+}
+
+func whoLabel(id *int64, set []storage.Lookup) string {
+	if id == nil {
+		return ""
+	}
+	return labelFor(*id, set)
+}
+
+func (s *Server) saveFile(relPath string, data []byte) error {
+	if err := os.MkdirAll(s.cfg.StorageDir, 0o700); err != nil {
+		return err
+	}
+	return os.WriteFile(filepath.Join(s.cfg.StorageDir, relPath), data, 0o600)
+}
+
+func detectMime(data []byte) string {
+	n := min(len(data), 512)
+	ct := http.DetectContentType(data[:n])
+	if i := strings.IndexByte(ct, ';'); i >= 0 {
+		ct = ct[:i]
+	}
+	return strings.TrimSpace(ct)
+}
+
+func allowedMime(mime string) bool {
+	return strings.HasPrefix(mime, "image/") || mime == "application/pdf"
+}
+
+func extFor(filename, mimeType string) string {
+	if ext := strings.ToLower(filepath.Ext(filename)); ext != "" && len(ext) <= 5 {
+		return ext
+	}
+	switch mimeType {
+	case "image/jpeg":
+		return ".jpg"
+	case "image/png":
+		return ".png"
+	case "image/gif":
+		return ".gif"
+	case "image/webp":
+		return ".webp"
+	case "application/pdf":
+		return ".pdf"
+	default:
+		return ".bin"
+	}
+}
+
+// newID returns a random UUIDv4 string.
+func newID() string {
+	var b [16]byte
+	_, _ = rand.Read(b[:])
+	b[6] = (b[6] & 0x0f) | 0x40
+	b[8] = (b[8] & 0x3f) | 0x80
+	return fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
+}
diff --git a/internal/web/upload_test.go b/internal/web/upload_test.go
new file mode 100644
index 0000000..493641d
--- /dev/null
+++ b/internal/web/upload_test.go
@@ -0,0 +1,195 @@
+package web
+
+import (
+	"bytes"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+
+	"maisym.com/hsa/internal/auth"
+	"maisym.com/hsa/internal/config"
+	"maisym.com/hsa/internal/storage"
+)
+
+func testServerWithStore(t *testing.T) *Server {
+	t.Helper()
+	var key [32]byte
+	copy(key[:], "web-test-key-32-bytes-padded!!!!")
+	store, err := storage.Open(filepath.Join(t.TempDir(), "test.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { store.Close() })
+	return &Server{
+		cfg: config.Config{
+			SessionKey:     key,
+			RequiredGroup:  "hsa-users",
+			StorageDir:     filepath.Join(t.TempDir(), "files"),
+			MaxUploadBytes: 32 << 20,
+		},
+		store: store,
+	}
+}
+
+func authCookie(t *testing.T, s *Server) *http.Cookie {
+	t.Helper()
+	sess := auth.Session{Subject: "jm@example.com", Groups: []string{"hsa-users"}}
+	v, err := auth.EncodeSession(sess, s.cfg.SessionKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &http.Cookie{Name: sessionCookie, Value: v}
+}
+
+// aCategoryID returns the id of a seeded category as a string.
+func aCategoryID(t *testing.T, s *Server) string {
+	t.Helper()
+	cats, err := s.store.ListCategories()
+	if err != nil || len(cats) == 0 {
+		t.Fatalf("ListCategories: %v", err)
+	}
+	return strconv.FormatInt(cats[0].ID, 10)
+}
+
+// fakePNG returns bytes that http.DetectContentType recognises as image/png.
+func fakePNG() []byte {
+	return append([]byte("\x89PNG\r\n\x1a\n"), []byte("fake-image-content")...)
+}
+
+func multipartUpload(t *testing.T, fields map[string]string, fileField, fileName string, fileData []byte) (*bytes.Buffer, string) {
+	t.Helper()
+	var body bytes.Buffer
+	mw := multipart.NewWriter(&body)
+	for k, v := range fields {
+		_ = mw.WriteField(k, v)
+	}
+	if fileData != nil {
+		fw, err := mw.CreateFormFile(fileField, fileName)
+		if err != nil {
+			t.Fatal(err)
+		}
+		fw.Write(fileData)
+	}
+	mw.Close()
+	return &body, mw.FormDataContentType()
+}
+
+func TestUpload_HappyPath_WritesFileAndRow(t *testing.T) {
+	s := testServerWithStore(t)
+	body, ct := multipartUpload(t,
+		map[string]string{"amount": "12.34", "receipt_date": "2026-06-01", "category_id": aCategoryID(t, s)},
+		"receipt", "receipt.png", fakePNG())
+
+	req := httptest.NewRequest(http.MethodPost, "/upload", body)
+	req.Header.Set("Content-Type", ct)
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200; body=%s", rec.Code, rec.Body.String())
+	}
+	if !strings.Contains(rec.Body.String(), "Receipt saved") {
+		t.Errorf("missing confirmation: %s", rec.Body.String())
+	}
+
+	// Row written.
+	n, err := s.store.CountActive()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 1 {
+		t.Fatalf("CountActive = %d, want 1", n)
+	}
+
+	// File written to disk (dual-write).
+	entries, err := os.ReadDir(s.cfg.StorageDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("storage dir has %d files, want 1", len(entries))
+	}
+	if !strings.HasSuffix(entries[0].Name(), ".png") {
+		t.Errorf("stored file name = %q, want .png suffix", entries[0].Name())
+	}
+}
+
+func TestUpload_BadAmount_RerendersWithErrorNoRow(t *testing.T) {
+	s := testServerWithStore(t)
+	body, ct := multipartUpload(t,
+		map[string]string{"amount": "abc", "receipt_date": "2026-06-01", "category_id": aCategoryID(t, s)},
+		"receipt", "receipt.png", fakePNG())
+
+	req := httptest.NewRequest(http.MethodPost, "/upload", body)
+	req.Header.Set("Content-Type", ct)
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (re-render)", rec.Code)
+	}
+	if !strings.Contains(rec.Body.String(), "valid amount") {
+		t.Errorf("missing amount error: %s", rec.Body.String())
+	}
+	n, _ := s.store.CountActive()
+	if n != 0 {
+		t.Errorf("CountActive = %d, want 0 (nothing stored on validation error)", n)
+	}
+}
+
+func TestUpload_RejectsNonImageNonPDF(t *testing.T) {
+	s := testServerWithStore(t)
+	body, ct := multipartUpload(t,
+		map[string]string{"amount": "5.00", "receipt_date": "2026-06-01", "category_id": aCategoryID(t, s)},
+		"receipt", "notes.txt", []byte("just plain text, not an image or pdf"))
+
+	req := httptest.NewRequest(http.MethodPost, "/upload", body)
+	req.Header.Set("Content-Type", ct)
+	req.AddCookie(authCookie(t, s))
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if !strings.Contains(rec.Body.String(), "images and PDFs") {
+		t.Errorf("expected mime rejection: %s", rec.Body.String())
+	}
+	n, _ := s.store.CountActive()
+	if n != 0 {
+		t.Errorf("CountActive = %d, want 0", n)
+	}
+}
+
+func TestExportDB_StreamsSQLiteFile(t *testing.T) {
+	s := testServerWithStore(t)
+	// Seed one receipt via the upload handler.
+	body, ct := multipartUpload(t,
+		map[string]string{"amount": "9.99", "receipt_date": "2026-06-01", "category_id": aCategoryID(t, s)},
+		"receipt", "r.png", fakePNG())
+	req := httptest.NewRequest(http.MethodPost, "/upload", body)
+	req.Header.Set("Content-Type", ct)
+	req.AddCookie(authCookie(t, s))
+	s.Routes().ServeHTTP(httptest.NewRecorder(), req)
+
+	for _, blobs := range []string{"true", "false"} {
+		req := httptest.NewRequest(http.MethodGet, "/export/db?blobs="+blobs, nil)
+		req.AddCookie(authCookie(t, s))
+		rec := httptest.NewRecorder()
+		s.Routes().ServeHTTP(rec, req)
+
+		if rec.Code != http.StatusOK {
+			t.Fatalf("blobs=%s: status = %d, want 200", blobs, rec.Code)
+		}
+		if ct := rec.Header().Get("Content-Type"); ct != "application/octet-stream" {
+			t.Errorf("blobs=%s: content-type = %q", blobs, ct)
+		}
+		if !strings.HasPrefix(rec.Body.String(), "SQLite format 3") {
+			t.Errorf("blobs=%s: body is not a SQLite file", blobs)
+		}
+	}
+}
diff --git a/internal/web/web.go b/internal/web/web.go
new file mode 100644
index 0000000..88f1bf3
--- /dev/null
+++ b/internal/web/web.go
@@ -0,0 +1,227 @@
+package web
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/coreos/go-oidc/v3/oidc"
+	"golang.org/x/oauth2"
+
+	"maisym.com/hsa/internal/auth"
+	"maisym.com/hsa/internal/classify"
+	"maisym.com/hsa/internal/config"
+	"maisym.com/hsa/internal/storage"
+)
+
+const (
+	sessionCookie = "hsa_session"
+	loginCookie   = "hsa_login"
+)
+
+// Server holds the wired dependencies for the HTTP handlers.
+type Server struct {
+	cfg        config.Config
+	provider   *oidc.Provider
+	oauth      *oauth2.Config
+	verifier   *oidc.IDTokenVerifier
+	store      *storage.Store
+	classifier *classify.Classifier // nil when classification is disabled
+}
+
+// NewServer performs OIDC discovery against the issuer and builds the server.
+// This makes a network call to the issuer's /.well-known/openid-configuration.
+// classifier may be nil to disable receipt auto-classification.
+func NewServer(ctx context.Context, cfg config.Config, store *storage.Store, classifier *classify.Classifier) (*Server, error) {
+	provider, err := oidc.NewProvider(ctx, cfg.IssuerURL)
+	if err != nil {
+		return nil, fmt.Errorf("oidc discovery against %s: %w", cfg.IssuerURL, err)
+	}
+
+	oauthCfg := &oauth2.Config{
+		ClientID:     cfg.ClientID,
+		ClientSecret: cfg.ClientSecret,
+		RedirectURL:  cfg.RedirectURL,
+		Endpoint:     provider.Endpoint(),
+		Scopes:       []string{oidc.ScopeOpenID, "profile", "email", "groups"},
+	}
+
+	return &Server{
+		cfg:        cfg,
+		provider:   provider,
+		oauth:      oauthCfg,
+		verifier:   provider.Verifier(&oidc.Config{ClientID: cfg.ClientID}),
+		store:      store,
+		classifier: classifier,
+	}, nil
+}
+
+// Routes returns the configured HTTP handler.
+func (s *Server) Routes() http.Handler {
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", s.handleHealthz)
+	mux.Handle("GET /static/", http.FileServerFS(staticFS))
+	mux.HandleFunc("GET /login", s.handleLogin)
+	mux.HandleFunc("GET /callback", s.handleCallback)
+	mux.HandleFunc("GET /logout", s.handleLogout)
+	mux.Handle("GET /{$}", s.requireAuth(http.HandlerFunc(s.handleUploadForm)))
+	mux.Handle("POST /upload", s.requireAuth(http.HandlerFunc(s.handleUpload)))
+	mux.Handle("POST /classify", s.requireAuth(http.HandlerFunc(s.handleClassify)))
+	mux.Handle("GET /manage", s.requireAuth(http.HandlerFunc(s.handleManage)))
+	mux.Handle("POST /manage/categories", s.requireAuth(http.HandlerFunc(s.handleAddCategory)))
+	mux.Handle("POST /manage/categories/rename", s.requireAuth(http.HandlerFunc(s.handleRenameCategory)))
+	mux.Handle("POST /manage/people", s.requireAuth(http.HandlerFunc(s.handleAddPerson)))
+	mux.Handle("POST /manage/people/rename", s.requireAuth(http.HandlerFunc(s.handleRenamePerson)))
+	mux.Handle("GET /export", s.requireAuth(http.HandlerFunc(s.handleExportPage)))
+	mux.Handle("GET /export/db", s.requireAuth(http.HandlerFunc(s.handleExportDB)))
+	return mux
+}
+
+func (s *Server) handleHealthz(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusOK)
+	fmt.Fprintln(w, "ok")
+}
+
+// handleLogin starts the OIDC flow: generate PKCE + state + nonce, stash them in
+// a short-lived encrypted cookie, and redirect to Authelia's authorize endpoint.
+func (s *Server) handleLogin(w http.ResponseWriter, r *http.Request) {
+	verifier, err := auth.GenerateVerifier()
+	if err != nil {
+		s.serverError(w, "generate verifier", err)
+		return
+	}
+	state, err := auth.GenerateState()
+	if err != nil {
+		s.serverError(w, "generate state", err)
+		return
+	}
+	nonce, err := auth.GenerateState() // reuse the random generator for the nonce
+	if err != nil {
+		s.serverError(w, "generate nonce", err)
+		return
+	}
+
+	ls := auth.LoginState{State: state, Verifier: verifier, Nonce: nonce}
+	encoded, err := auth.EncodeLoginState(ls, s.cfg.SessionKey)
+	if err != nil {
+		s.serverError(w, "encode login state", err)
+		return
+	}
+	s.setCookie(w, loginCookie, encoded, 10*time.Minute)
+
+	challenge := auth.ChallengeS256(verifier)
+	url := auth.AuthorizeURL(s.oauth, state, challenge, oidc.Nonce(nonce))
+	http.Redirect(w, r, url, http.StatusFound)
+}
+
+// handleCallback completes the OIDC flow: validate state, exchange the code with
+// PKCE, verify the ID token, check the group, and set the session cookie.
+func (s *Server) handleCallback(w http.ResponseWriter, r *http.Request) {
+	// Recover the login state from the cookie.
+	c, err := r.Cookie(loginCookie)
+	if err != nil {
+		http.Error(w, "missing login state; start at /login", http.StatusBadRequest)
+		return
+	}
+	ls, err := auth.DecodeLoginState(c.Value, s.cfg.SessionKey)
+	if err != nil {
+		http.Error(w, "invalid login state", http.StatusBadRequest)
+		return
+	}
+	s.clearCookie(w, loginCookie)
+
+	// CSRF: the state we issued must match the one returned.
+	if r.URL.Query().Get("state") != ls.State {
+		http.Error(w, "state mismatch", http.StatusBadRequest)
+		return
+	}
+
+	// Exchange the authorization code, sending the PKCE verifier.
+	code := r.URL.Query().Get("code")
+	token, err := s.oauth.Exchange(r.Context(), code, oauth2.VerifierOption(ls.Verifier))
+	if err != nil {
+		s.serverError(w, "token exchange", err)
+		return
+	}
+
+	rawIDToken, ok := token.Extra("id_token").(string)
+	if !ok {
+		http.Error(w, "no id_token in response", http.StatusBadGateway)
+		return
+	}
+	idToken, err := s.verifier.Verify(r.Context(), rawIDToken)
+	if err != nil {
+		s.serverError(w, "verify id_token", err)
+		return
+	}
+	if idToken.Nonce != ls.Nonce {
+		http.Error(w, "nonce mismatch", http.StatusBadRequest)
+		return
+	}
+
+	// Authelia serves groups/email from the UserInfo endpoint rather than the ID
+	// token by default, so read claims from the ID token and merge in UserInfo.
+	type oidcClaims struct {
+		Email             string   `json:"email"`
+		PreferredUsername string   `json:"preferred_username"`
+		Groups            []string `json:"groups"`
+	}
+	var idClaims oidcClaims
+	if err := idToken.Claims(&idClaims); err != nil {
+		s.serverError(w, "parse id token claims", err)
+		return
+	}
+
+	var uiClaims oidcClaims
+	if userInfo, err := s.provider.UserInfo(r.Context(), oauth2.StaticTokenSource(token)); err == nil {
+		_ = userInfo.Claims(&uiClaims)
+	} else {
+		log.Printf("warning: userinfo fetch failed: %v", err)
+	}
+
+	groups := idClaims.Groups
+	if len(groups) == 0 {
+		groups = uiClaims.Groups
+	}
+	email := idClaims.Email
+	if email == "" {
+		email = uiClaims.Email
+	}
+	username := idClaims.PreferredUsername
+	if username == "" {
+		username = uiClaims.PreferredUsername
+	}
+
+	subject := email
+	if subject == "" {
+		subject = username
+	}
+	log.Printf("login attempt: subject=%q groups=%v", subject, groups)
+
+	// Authorization gate: must be in the required group.
+	if !auth.IsAuthorized(groups, s.cfg.RequiredGroup) {
+		http.Error(w, fmt.Sprintf("403: not a member of %q", s.cfg.RequiredGroup), http.StatusForbidden)
+		return
+	}
+
+	sess := auth.Session{Subject: subject, Groups: groups, IssuedAt: time.Now().UTC()}
+	encoded, err := auth.EncodeSession(sess, s.cfg.SessionKey)
+	if err != nil {
+		s.serverError(w, "encode session", err)
+		return
+	}
+	s.setCookie(w, sessionCookie, encoded, 12*time.Hour)
+	http.Redirect(w, r, "/", http.StatusFound)
+}
+
+func (s *Server) handleLogout(w http.ResponseWriter, r *http.Request) {
+	s.clearCookie(w, sessionCookie)
+	http.Redirect(w, r, "/login", http.StatusFound)
+}
+
+func (s *Server) serverError(w http.ResponseWriter, what string, err error) {
+	log.Printf("error: %s: %v", what, err)
+	http.Error(w, "internal server error", http.StatusInternalServerError)
+}
diff --git a/internal/web/web_test.go b/internal/web/web_test.go
new file mode 100644
index 0000000..e972600
--- /dev/null
+++ b/internal/web/web_test.go
@@ -0,0 +1,128 @@
+package web
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"maisym.com/hsa/internal/auth"
+	"maisym.com/hsa/internal/config"
+)
+
+func testServer() *Server {
+	var key [32]byte
+	copy(key[:], "web-test-key-32-bytes-padded!!!!")
+	return &Server{cfg: config.Config{
+		SessionKey:    key,
+		RequiredGroup: "hsa-users",
+		SecureCookies: false,
+	}}
+}
+
+func TestStaticCSS(t *testing.T) {
+	s := testServer()
+	req := httptest.NewRequest(http.MethodGet, "/static/style.css", nil)
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+	if !strings.Contains(rec.Body.String(), "font-family") {
+		t.Errorf("CSS not served: %q", rec.Body.String())
+	}
+}
+
+func TestHealthz(t *testing.T) {
+	s := testServer()
+	req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+	if !strings.Contains(rec.Body.String(), "ok") {
+		t.Errorf("body = %q, want to contain ok", rec.Body.String())
+	}
+}
+
+func TestHome_NoSession_RedirectsToLogin(t *testing.T) {
+	s := testServer()
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusFound {
+		t.Fatalf("status = %d, want 302", rec.Code)
+	}
+	if loc := rec.Header().Get("Location"); loc != "/login" {
+		t.Errorf("Location = %q, want /login", loc)
+	}
+}
+
+func TestHome_ValidSession_ShowsUploadForm(t *testing.T) {
+	s := testServerWithStore(t)
+	sess := auth.Session{Subject: "jm@example.com", Groups: []string{"hsa-users"}}
+	cookie, err := auth.EncodeSession(sess, s.cfg.SessionKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	req.AddCookie(&http.Cookie{Name: sessionCookie, Value: cookie})
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+	body := rec.Body.String()
+	if !strings.Contains(body, "jm@example.com") {
+		t.Errorf("body missing subject: %q", body)
+	}
+	if !strings.Contains(body, "Add receipt") {
+		t.Errorf("body missing upload form: %q", body)
+	}
+}
+
+func TestHome_TamperedSession_RedirectsToLogin(t *testing.T) {
+	s := testServer()
+	sess := auth.Session{Subject: "jm@example.com", Groups: []string{"hsa-users"}}
+	cookie, _ := auth.EncodeSession(sess, s.cfg.SessionKey)
+	tampered := cookie[:len(cookie)-3] + "AAA"
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	req.AddCookie(&http.Cookie{Name: sessionCookie, Value: tampered})
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusFound {
+		t.Fatalf("status = %d, want 302", rec.Code)
+	}
+	if loc := rec.Header().Get("Location"); loc != "/login" {
+		t.Errorf("Location = %q, want /login", loc)
+	}
+}
+
+func TestLogout_ClearsCookieAndRedirects(t *testing.T) {
+	s := testServer()
+	req := httptest.NewRequest(http.MethodGet, "/logout", nil)
+	rec := httptest.NewRecorder()
+	s.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusFound {
+		t.Fatalf("status = %d, want 302", rec.Code)
+	}
+	// The session cookie should be expired (MaxAge < 0).
+	var cleared bool
+	for _, c := range rec.Result().Cookies() {
+		if c.Name == sessionCookie && c.MaxAge < 0 {
+			cleared = true
+		}
+	}
+	if !cleared {
+		t.Error("logout did not clear the session cookie")
+	}
+}
diff --git a/plan.md b/plan.md
new file mode 100644
index 0000000..b3f63b3
--- /dev/null
+++ b/plan.md
@@ -0,0 +1,157 @@
+# HSA Receipt Tracker — Implementation Plan (v1)
+
+Companion to `spec.md`. This is the *how* and the *order*; `spec.md` is the *what*.
+Strategy: red/green (write a failing test, make it pass) wherever the logic is pure
+and deterministic. Where behaviour depends on the live world (the real OIDC
+round-trip against Authelia, a camera, a browser), we verify manually instead and
+say so explicitly.
+
+---
+
+## Decisions locked (from consultation)
+
+| Topic            | Decision                                                        |
+|------------------|-----------------------------------------------------------------|
+| Stack            | Go — single static binary, systemd in LXC, SQLite               |
+| App domain       | `hsa.maisym.com`                                                 |
+| Auth issuer      | `auth.maisym.com`                                                |
+| OIDC client      | Confidential + PKCE                                              |
+| Auth group       | `hsa-users` (gates access; not in group → 403)                  |
+| Session          | Encrypted, signed cookie (stateless, no server-side store)      |
+| Edit             | Designed-for, **not built** in v1                               |
+| Export           | `/export/db` only, with include-blobs **yes/no** toggle         |
+| Files            | PDF + images, accepted as-is; client compression is **phase 2** |
+| View list/detail | Out of scope for v1                                             |
+| Auth testing     | Unit-test pure pieces; verify live round-trip manually          |
+
+---
+
+## Build order (milestones)
+
+- **M0 — Auth flow only.** App authenticates against live Authelia and shows a
+  "you're logged in" result, including the group gate. *This is the first thing JM
+  wants to see running.* Detailed below.
+- **M1 — Storage layer.** SQLite schema + receipts data access (insert, soft-delete,
+  fetch). Dual-write (filesystem + BLOB) in one transaction.
+- **M2 — Upload flow.** Mobile-first capture/upload form (amount, date, category),
+  PDF+image handling, validation, store both copies, confirmation page.
+- **M3 — Export.** `GET /export/db` with include-blobs toggle, via point-in-time
+  snapshot (never the live DB file).
+- **Phase 2 / later.** Client-side image compression; edit functionality.
+
+Only **M0 is planned in detail** below — we plan the next milestone when we get
+there, so the plan stays honest.
+
+---
+
+## Milestone 0 — Auth flow
+
+**Goal / acceptance:** Open `hsa.maisym.com` in a phone/browser → redirected to
+`auth.maisym.com` → log in → land back on a page that reads roughly:
+
+> Logged in as `jeanmi.tremblay@gmail.com` · groups: `[hsa-users]` · access: **GRANTED**
+
+…and a user who is **not** in `hsa-users` gets a **403**. That single screen proves
+the entire chain: OIDC+PKCE round-trip, identity claims, group claim, and the
+authorization gate.
+
+### Step 0.1 — Prerequisites (setup, not tested)
+
+- Install Go toolchain (not currently present on this machine).
+- `git init` the repo.
+- `go mod init` — **module path TBD** (see Open Questions). Default proposal:
+  `maisym.com/hsa`.
+- Project skeleton: `cmd/hsa/main.go`, `internal/auth/`, `internal/web/`,
+  `internal/config/`.
+
+### Step 0.2 — JM's Authelia-side config (your action; app can't do this)
+
+Enumerated here so the app and Authelia agree on every value:
+
+- Create group `hsa-users`; add both users.
+- Register a **confidential** OIDC client in `identity_providers.oidc.clients`:
+  - `client_id`: e.g. `hsa-tracker`
+  - `client_secret`: random, stored **hashed** (via `authelia crypto hash generate`)
+  - `redirect_uris`: `https://hsa.maisym.com/callback`
+    (+ a dev redirect, e.g. `http://localhost:8080/callback` — see Open Questions)
+  - `scopes`: `openid`, `profile`, `email`, `groups`
+  - `response_types`: `code`; `grant_types`: `authorization_code`
+  - PKCE: require `S256`
+  - token endpoint auth method: `client_secret_basic` (confirm at execution)
+- Reload Authelia.
+
+### Step 0.3 — App config (env vars)
+
+`ISSUER_URL`, `CLIENT_ID`, `CLIENT_SECRET`, `REDIRECT_URL`, `REQUIRED_GROUP`
+(=`hsa-users`), `SESSION_KEY` (cookie encryption key), `LISTEN_ADDR`. Loaded and
+validated at startup (fail fast if any missing).
+
+### Step 0.4 — Red/green units (pure logic)
+
+Each is a failing test first, then the implementation:
+
+1. **PKCE** — `GenerateVerifier()` (43–128 URL-safe chars) and
+   `ChallengeS256(verifier)`. Test with the **RFC 7636 Appendix B** known vector
+   (fixed verifier → known challenge) so the encoding is provably correct.
+2. **State / nonce** — sufficient length, two calls differ (CSRF + replay defense).
+3. **Session codec** — `Encode(session)`/`Decode(cookie)` round-trips; a **tampered**
+   value is rejected; a value signed with the **wrong key** is rejected.
+4. **Authorization decision** — `IsAuthorized(groups, required) bool`. Table tests:
+   in-group → true; empty groups → false; other-group-only → false. *This is the
+   403 rule, tested in isolation.*
+5. **Authorize-URL builder** — construct `oauth2.Config` with fixed endpoints (no
+   network/discovery) and assert `AuthCodeURL` carries `state`, `code_challenge`,
+   `code_challenge_method=S256`, and the right scopes.
+
+### Step 0.5 — Handlers tested via `httptest` (no live Authelia)
+
+- `GET /healthz` → 200.
+- `GET /` (protected) behind `RequireAuth`: forged **valid** session cookie → 200 and
+  the page shows identity + groups; **no/invalid** cookie → 302 to `/login`.
+- `GET /logout` → clears cookie, 302.
+
+### Step 0.6 — Live round-trip (manual verification — the M0 acceptance)
+
+Not unit-testable (needs real Authelia + a human clicking login):
+
+- `GET /login` → builds PKCE+state, stashes verifier/state in a short-lived cookie,
+  302 to Authelia's authorize endpoint.
+- `GET /callback` → validate `state`, exchange `code` (with PKCE verifier), verify
+  the ID token, extract claims, run `IsAuthorized`, set the session cookie, redirect
+  to `/`. (The pure sub-parts — claim extraction, group gate — are already
+  red/green from 0.4.)
+
+**Manual test script:**
+1. Run the app with real config (locally with the dev redirect, or deployed in the
+   LXC behind Caddy).
+2. Browser → app → redirected to `auth.maisym.com` → log in → returned to success
+   page showing identity + `[hsa-users]` + **GRANTED**.
+3. Negative path: an account **not** in `hsa-users` → **403**.
+
+### M0 done =
+
+All red/green units green, `httptest` handler tests green, and the manual
+round-trip (both positive and 403 paths) confirmed against live Authelia.
+
+---
+
+## Open questions (revisit before/at execution — not guessing)
+
+1. **Module path / repo name** — `maisym.com/hsa`? a GitHub path? Will there be a
+   GitHub remote, or local-only for now?
+2. **Dev redirect URI** — do you want to test M0 *locally first* (needs a
+   `http://localhost:8080/callback` redirect added to the Authelia client), or
+   **deploy-to-LXC-first** and test only at `https://hsa.maisym.com`?
+3. **Token endpoint auth method** — `client_secret_basic` vs `_post`. Pick when we
+   wire it; basic is the default assumption.
+4. **Infra ownership** — Caddy vhost + systemd unit: you handle, or you want me to
+   draft the unit file / Caddyfile snippet as part of M0?
+
+## Deferred to later milestones (noted so we don't design against them)
+
+- SQLite driver choice — lean **`modernc.org/sqlite`** (pure Go, keeps the static
+  binary, no cgo). Decide at M1.
+- Edit (v1: schema/storage must not preclude it — on a future edit, update FS file
+  and BLOB in one transaction, keep `file_path` UUID stable).
+- Client-side image compression (phase 2): re-encode camera images to JPEG/WebP at a
+  quality factor before upload; PDFs pass through untouched.
diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..1eab91e
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+set -euo pipefail
+cd "$(dirname "$0")/.."
+source scripts/go-env.sh
+go build ./...
diff --git a/scripts/go-env.sh b/scripts/go-env.sh
new file mode 100755
index 0000000..7c98af7
--- /dev/null
+++ b/scripts/go-env.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+# Shared helper: put the Go toolchain on PATH. Source this from other scripts.
+# The toolchain isn't on the default PATH on this machine.
+if ! command -v go >/dev/null 2>&1; then
+  export PATH="$PATH:/home/jm/go-toolchain/go/bin"
+fi
diff --git a/scripts/test.sh b/scripts/test.sh
new file mode 100755
index 0000000..bf148c5
--- /dev/null
+++ b/scripts/test.sh
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+set -euo pipefail
+cd "$(dirname "$0")/.."
+source scripts/go-env.sh
+go test ./... "$@"
diff --git a/secret.md b/secret.md
new file mode 100644
index 0000000..d812911
--- /dev/null
+++ b/secret.md
@@ -0,0 +1,192 @@
+# Authelia OIDC Client Setup
+
+One-time setup. Do this before running the app for the first time.
+
+---
+
+## Step 1 — Generate the OIDC client secret
+
+Run `secret.sh` on your **Authelia host** (needs `openssl` + `authelia` in PATH):
+
+```bash
+bash secret.sh
+```
+
+Output looks like:
+
+```
+=== Plaintext secret (app .env → OIDC_CLIENT_SECRET) ===
+xK9mP2...64chars...
+
+=== Authelia hash (configuration.yml → client_secret) ===
+$argon2id$v=19$m=65536,t=3,p=4$...
+```
+
+---
+
+## Step 2 — Save the plaintext secret
+
+The plaintext secret is **only shown once**. Save it immediately to the app's env file on the LXC where the app will run:
+
+```
+# /etc/hsa/hsa.env  (create this file, chmod 600, owned by the service user)
+OIDC_CLIENT_SECRET=xK9mP2...64chars...
+```
+
+Full env file contents are documented in the app's README once we get there.
+For now just save `OIDC_CLIENT_SECRET=<value>` somewhere safe.
+
+**Never commit this file to git.** `.gitignore` already excludes `.env` files.
+
+---
+
+## Step 3 — Generate the OIDC signing key (RSA / RS256)
+
+Authelia needs a signing key for the JWTs it issues. **It must be RSA (RS256)** — OIDC
+mandates RS256 as the baseline and Authelia rejects Ed25519/EdDSA for the OIDC JWKS.
+
+Generate it and place it in the secrets dir, owned by the Authelia service user so the
+process can read it (it runs non-root; a root-owned `chmod 600` key gives
+`permission denied`):
+
+```bash
+sudo mkdir -p /tmp/oidc-rsa
+sudo authelia crypto pair rsa generate --bits 2048 --directory /tmp/oidc-rsa
+sudo install -o authelia -g authelia -m 600 /tmp/oidc-rsa/private.pem /etc/authelia/secrets/oidc_jwks.pem
+sudo rm -rf /tmp/oidc-rsa
+```
+
+(Confirm the owner matches your other secrets: `ls -l /etc/authelia/secrets/`. Substitute
+if it's not `authelia:authelia`.)
+
+---
+
+## Step 4 — Add the jwks + client block to configuration.yml
+
+The key is referenced from the .pem file via Authelia's template filter, so it never gets
+copied into the config. This requires enabling the template filter (see the note after the
+block — it's a one-line systemd env var).
+
+In `configuration.yml`, the full `identity_providers.oidc` section should look like this
+(append the `hsa-tracker` entry if you already have other clients):
+
+```yaml
+identity_providers:
+  oidc:
+    jwks:
+      - key_id: 'main'
+        algorithm: 'RS256'
+        use: 'sig'
+        key: {{ secret "/etc/authelia/secrets/oidc_jwks.pem" | mindent 10 "|" | msquote }}
+    clients:
+      - client_id: 'hsa-tracker'
+        client_name: 'HSA Receipt Tracker'
+        client_secret: '$argon2id$v=19$...'   # the hash from secret.sh
+        public: false
+        authorization_policy: 'two_factor'
+        require_pkce: true
+        pkce_challenge_method: 'S256'
+        redirect_uris:
+          - 'https://hsa.maisym.com/callback'
+          - 'http://localhost:8080/callback'          # for local dev testing
+        scopes:
+          - 'openid'
+          - 'profile'
+          - 'email'
+          - 'groups'
+        response_types:
+          - 'code'
+        grant_types:
+          - 'authorization_code'
+        token_endpoint_auth_method: 'client_secret_basic'
+        userinfo_signed_response_alg: 'none'
+```
+
+### Required: enable the template config filter
+
+The `{{ secret ... }}` syntax above only works when Authelia's **template config filter**
+is enabled — it's OFF by default. If you skip this, the `{{ ... }}` is passed to the YAML
+parser raw and breaks the *entire* config file (symptom: `yaml: invalid map key` plus a
+cascade of "X not configured" errors — those cascade errors are a red herring caused by
+the file failing to parse).
+
+Enable the filter on the service:
+
+```bash
+sudo systemctl edit authelia
+```
+
+Add, save, exit:
+
+```
+[Service]
+Environment=X_AUTHELIA_CONFIG_FILTERS=template
+```
+
+Confirm it registered before restarting:
+
+```bash
+systemctl cat authelia | grep -i filter   # should show your Environment line
+```
+
+Then restart (env changes need a full restart, not reload):
+
+```bash
+sudo systemctl restart authelia
+```
+
+### Gotchas worth knowing
+
+- **The key must be RSA and readable by the Authelia service user.** Ed25519 is rejected
+  by the OIDC JWKS (RS256 is mandatory). A root-owned `chmod 600` key gives the process
+  `permission denied` — keep it in `/etc/authelia/secrets/` owned by `authelia`.
+- **`authelia config validate` run manually shows false positives** for `jwt_secret` and
+  `storage encryption_key`, because the `*_FILE` secrets are injected by systemd and aren't
+  present in a manual shell. Under the running service they're fine — only trust the
+  `journalctl` output after a real restart for those two.
+
+---
+
+## Step 5 — Create the hsa-users group and add both users
+
+In your Authelia users file (typically `users_database.yml`), add `hsa-users` to the `groups` list for each user:
+
+```yaml
+users:
+  jm:
+    disabled: false
+    displayname: 'JM'
+    password: '$argon2id$...'
+    email: 'jm@jmopines.com'
+    groups:
+      - 'admins'
+      - 'hsa-users'
+```
+
+Repeat for the second user.
+
+---
+
+## Step 6 — Restart Authelia
+
+Use `restart`, not `reload` — config-file and environment changes are only picked up on a
+full restart. (The users/groups file in Step 5 is auto-reloaded by Authelia, but a restart
+covers everything at once.)
+
+```bash
+sudo systemctl restart authelia
+```
+
+Verify it came up clean (no `level=error` or `level=fatal` lines):
+
+```bash
+journalctl -u authelia -n 20
+```
+
+---
+
+## Verification
+
+Once the app is running, opening `http://localhost:8080` (or `https://hsa.maisym.com`) should
+redirect you to `auth.maisym.com`. After login + YubiKey 2FA it should land on a page showing
+your identity and `[hsa-users]` group.
diff --git a/secret.sh b/secret.sh
new file mode 100755
index 0000000..338b9d5
--- /dev/null
+++ b/secret.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Generates a random OIDC client secret and prints:
+#   - the plaintext  → goes in the app's .env as OIDC_CLIENT_SECRET
+#   - the Authelia hash → goes in Authelia's configuration.yml client_secret field
+# Run this on the Authelia host (needs openssl + authelia in PATH).
+set -euo pipefail
+
+SECRET=$(openssl rand -base64 48 | tr -d '/+=' | cut -c1-64)
+
+echo "=== Plaintext secret (app .env → OIDC_CLIENT_SECRET) ==="
+echo "$SECRET"
+echo ""
+echo "=== Authelia hash (configuration.yml → client_secret) ==="
+authelia crypto hash generate argon2 --password "$SECRET"
diff --git a/spec.md b/spec.md
new file mode 100644
index 0000000..13240a0
--- /dev/null
+++ b/spec.md
@@ -0,0 +1,109 @@
+HSA Receipt Tracker — Requirements (v1)
+Purpose
+Capture and archive HSA-eligible receipts for future reimbursement and tax substantiation. No parsing, no OCR, no reporting.
+Users
+
+Two users, both with full access (shared visibility).
+Authentication via Authelia OIDC.
+Authorization via membership in an Authelia group (e.g. hsa-users).
+Not in the group → 403. No other roles or gradations.
+
+Core flow
+
+User opens app on phone (mobile-first UI; camera access matters).
+Takes a photo of a receipt, or selects an existing image / PDF from device.
+Form prompts for: amount, date, category.
+Submit → image stored to disk, metadata row inserted into DB.
+Confirmation page, with options to view list or add another.
+
+Data model
+receipts table:
+
+id (UUID)
+uploaded_by (Authelia username or email)
+uploaded_at (server timestamp)
+receipt_date (user-supplied date on the receipt)
+amount_cents (integer — never store money as float)
+category (enum)
+file_path (relative path on disk — the filesystem copy)
+image_data (BLOB — the receipt file bytes, also stored in the DB itself)
+file_size_bytes (integer — convenience for listings/exports)
+original_filename (preserved for reference)
+mime_type
+deleted_at (nullable — soft delete)
+
+Categories (fixed list, hardcoded for v1):
+
+Medical
+Dental
+Vision
+Pharmacy
+Other
+
+Storage
+
+Receipt images/PDFs are stored in BOTH places on upload:
+  1. Filesystem at a configurable path, filename randomized (UUID) on save
+     (file_path) — used as the primary path for serving.
+  2. As a BLOB inside the SQLite database (image_data column) — so the single
+     .db file is a complete, self-contained dataset (metadata + files).
+
+Rationale: the filesystem copy keeps serving simple/efficient; the DB blob makes
+backup and export trivial ("hand over one file" gets everything, even without the
+files directory). Written once at upload; no edit in v1, so the two copies never
+diverge. Acceptable cost because scale is tiny (two users, small files).
+original_filename and mime_type kept as metadata for download/serving.
+Backups remain JM's responsibility outside the app.
+
+Auth integration
+
+OIDC with PKCE against https://auth.jmopines.com.
+Session cookie after successful callback.
+/login, /callback, /logout, /healthz are public; everything else requires a valid session.
+Group claim (hsa-users) gates access; otherwise 403.
+
+Deployment
+
+Runs as a systemd service in an LXC.
+Caddy reverse proxy at https://hsa.jmopines.com (TBD: maisym.com vs jmopines.com).
+SQLite DB + filesystem storage. No external dependencies (no Redis, no Postgres, no S3).
+
+Operations
+
+Soft delete supported (set deleted_at, hide from default list views).
+No edit functionality in v1 — fix mistakes by deleting and re-adding.
+
+Database export
+
+Authenticated users (hsa-users group) can download the data for offline use.
+
+Two endpoints:
+
+GET /export/db — downloads a consistent copy of the SQLite database file. Because
+  images are stored as BLOBs in the DB, this single file IS the complete dataset
+  (metadata + all receipt images). This is the primary export.
+  - Must NOT serve the live DB file directly (avoids locking/corruption against the
+    running app). Use SQLite's online backup API (or VACUUM INTO a temp file) to
+    produce a point-in-time snapshot, then stream that.
+  - Content-Type: application/octet-stream; filename like hsa-export-YYYY-MM-DD.db.
+
+GET /export/archive (optional convenience) — downloads a zip with the image files
+  extracted to normal files (named by original_filename) plus a CSV/JSON of the
+  metadata, for someone who wants the pictures as browseable files rather than
+  inside a DB.
+  - Streamed zip to avoid buffering large archives in memory.
+  - filename like hsa-export-YYYY-MM-DD.zip.
+
+Notes:
+  - Amounts remain integer cents in the export; consumers divide by 100 for dollars.
+  - Read-only operation; no app state is mutated.
+
+Out of scope for v1
+
+OCR / image content parsing
+Reports, totals, dashboards
+CSV / tax-software export
+Reimbursement tracking (paid vs pending status)
+In-place editing of existing receipts
+Multi-tenancy or per-user data isolation
+Notification / reminders
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