feat(auth): JWT jti + per-track TTLs (Track 4 <=1h) + revocation + refresh endpoint

Closes the 'JWT hygiene' gap identified by the review:

  - 24h TTL was used for every track, including Track 4 operator sessions
    carrying operator.write.* permissions.
  - Tokens had no server-side revocation path; rotating JWT_SECRET was
    the only way to invalidate a session, which would punt every user.
  - Tokens carried no jti, so individual revocation was impossible even
    with a revocations table.

Changes:

Migration 0016_jwt_revocations (up + down):
  - CREATE TABLE jwt_revocations (jti PK, address, track,
    token_expires_at, revoked_at, reason) plus indexes on address and
    token_expires_at. Append-only; idempotent on duplicate jti.

backend/auth/wallet_auth.go:
  - tokenTTLs map: track 1 = 12h, 2 = 8h, 3 = 4h, 4 = 60m. tokenTTLFor
    returns the ceiling; default is 12h for unknown tracks.
  - generateJWT now embeds a 128-bit random jti (hex-encoded) and uses
    the per-track TTL instead of a hardcoded 24h.
  - parseJWT: shared signature-verification + claim-extraction helper
    used by ValidateJWT and RefreshJWT. Returns address, track, jti, exp.
  - jtiFromToken: parses jti from an already-trusted token without a
    second crypto roundtrip.
  - isJTIRevoked: EXISTS query against jwt_revocations, returning
    ErrJWTRevocationStorageMissing when the table is absent (migration
    not run yet) so callers can surface a 503 rather than silently
    treating every token as valid.
  - RevokeJWT(ctx, token, reason): records the jti; idempotent via
    ON CONFLICT (jti) DO NOTHING. Refuses legacy tokens without jti.
  - RefreshJWT(ctx, token): validates, revokes the old token (reason
    'refresh'), and mints a new token with fresh jti + fresh TTL. Same
    (address, track) as the inbound token, same permissions set.
  - ValidateJWT now consults jwt_revocations when a DB is configured;
    returns ErrJWTRevoked for revoked tokens.

backend/api/rest/auth_refresh.go (new):
  - POST /api/v1/auth/refresh handler: expects 'Authorization: Bearer
    <jwt>'; returns WalletAuthResponse with the new token. Maps
    ErrJWTRevoked to 401 token_revoked and ErrWalletAuthStorageNotInitialized
    to 503.
  - POST /api/v1/auth/logout handler: same header contract, idempotent,
    returns {status: ok}. Returns 503 when the revocations table
    isn't present so ops know migration 0016 hasn't run.
  - Both handlers reuse the existing extractBearerToken helper from
    auth.go so parsing is consistent with the rest of the access layer.

backend/api/rest/routes.go:
  - Registered /api/v1/auth/refresh and /api/v1/auth/logout.

Tests:
  - TestTokenTTLForTrack4IsShort: track 4 TTL <= 1h.
  - TestTokenTTLForTrack1Track2Track3AreReasonable: bounded at 12h.
  - TestGeneratedJWTCarriesJTIClaim: jti is present, 128 bits / 32 hex.
  - TestGeneratedJWTExpIsTrackAppropriate: exp matches tokenTTLFor per
    track within a couple-second tolerance.
  - TestRevokeJWTWithoutDBReturnsError: a WalletAuth with nil db must
    refuse to revoke rather than silently pretending it worked.
  - All pre-existing wallet_auth tests still pass.

Also fixes a small SA4006/SA4017 regression in mission_control.go that
PR #5 introduced by shadowing the outer err with json.Unmarshal's err
return. Reworked to uerr so the outer err and the RPC fallback still
function as intended.

Verification:
  go build ./...         clean
  go vet ./...           clean
  go test ./auth/...     PASS (including new tests)
  go test ./api/rest/... PASS
  staticcheck ./auth/... ./api/rest/...  clean on SA4006/SA4017/SA1029

Advances completion criterion 3 (JWT hygiene): 'Track 4 sessions TTL
<= 1h; server-side revocation list (keyed on jti) enforced on every
token validation; refresh endpoint rotates the token in place so the
short TTL is usable in practice; logout endpoint revokes immediately.'

backend/api/rest/auth_refresh.go

@@ -0,0 +1,92 @@
+package rest
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"github.com/explorer/backend/auth"
+)
+
+// handleAuthRefresh implements POST /api/v1/auth/refresh.
+//
+// Contract:
+//   - Requires a valid, unrevoked wallet JWT in the Authorization header.
+//   - Mints a new JWT for the same address+track with a fresh jti and a
+//     fresh per-track TTL.
+//   - Revokes the presented token so it cannot be reused.
+//
+// This is the mechanism that makes the short Track-4 TTL (60 min in
+// PR #8) acceptable: operators refresh while the token is still live
+// rather than re-signing a SIWE message every hour.
+func (s *Server) handleAuthRefresh(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		writeError(w, http.StatusMethodNotAllowed, "method_not_allowed", "Method not allowed")
+		return
+	}
+	if s.walletAuth == nil {
+		writeError(w, http.StatusServiceUnavailable, "service_unavailable", "wallet auth not configured")
+		return
+	}
+
+	token := extractBearerToken(r)
+	if token == "" {
+		writeError(w, http.StatusUnauthorized, "unauthorized", "missing or malformed Authorization header")
+		return
+	}
+
+	resp, err := s.walletAuth.RefreshJWT(r.Context(), token)
+	if err != nil {
+		switch {
+		case errors.Is(err, auth.ErrJWTRevoked):
+			writeError(w, http.StatusUnauthorized, "token_revoked", err.Error())
+		case errors.Is(err, auth.ErrWalletAuthStorageNotInitialized):
+			writeError(w, http.StatusServiceUnavailable, "service_unavailable", err.Error())
+		default:
+			writeError(w, http.StatusUnauthorized, "unauthorized", err.Error())
+		}
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(resp)
+}
+
+// handleAuthLogout implements POST /api/v1/auth/logout.
+//
+// Records the presented token's jti in jwt_revocations so subsequent
+// calls to ValidateJWT will reject it. Idempotent: logging out twice
+// with the same token succeeds.
+func (s *Server) handleAuthLogout(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		writeError(w, http.StatusMethodNotAllowed, "method_not_allowed", "Method not allowed")
+		return
+	}
+	if s.walletAuth == nil {
+		writeError(w, http.StatusServiceUnavailable, "service_unavailable", "wallet auth not configured")
+		return
+	}
+
+	token := extractBearerToken(r)
+	if token == "" {
+		writeError(w, http.StatusUnauthorized, "unauthorized", "missing or malformed Authorization header")
+		return
+	}
+
+	if err := s.walletAuth.RevokeJWT(r.Context(), token, "logout"); err != nil {
+		switch {
+		case errors.Is(err, auth.ErrJWTRevocationStorageMissing):
+			// Surface 503 so ops know migration 0016 hasn't run; the
+			// client should treat the token as logged out locally.
+			writeError(w, http.StatusServiceUnavailable, "service_unavailable", err.Error())
+		default:
+			writeError(w, http.StatusUnauthorized, "unauthorized", err.Error())
+		}
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]any{
+		"status": "ok",
+	})
+}

backend/api/rest/mission_control.go

@@ -475,8 +475,12 @@ func (s *Server) HandleMissionControlBridgeTrace(w http.ResponseWriter, r *http.
 	body, statusCode, err := fetchBlockscoutTransaction(r.Context(), tx)
 	if err == nil && statusCode == http.StatusOK {
 		var txDoc map[string]interface{}
-		if err := json.Unmarshal(body, &txDoc); err != nil {
-			err = fmt.Errorf("invalid blockscout JSON")
+		if uerr := json.Unmarshal(body, &txDoc); uerr != nil {
+			// Fall through to the RPC fallback below. The HTTP fetch
+			// succeeded but the body wasn't valid JSON; letting the code
+			// continue means we still get addresses from RPC instead of
+			// failing the whole request.
+			_ = uerr
 		} else {
 			fromAddr = extractEthAddress(txDoc["from"])
 			toAddr = extractEthAddress(txDoc["to"])

backend/api/rest/routes.go

@@ -52,6 +52,8 @@ func (s *Server) SetupRoutes(mux *http.ServeMux) {
 	// Auth endpoints
 	mux.HandleFunc("/api/v1/auth/nonce", s.handleAuthNonce)
 	mux.HandleFunc("/api/v1/auth/wallet", s.handleAuthWallet)
+	mux.HandleFunc("/api/v1/auth/refresh", s.handleAuthRefresh)
+	mux.HandleFunc("/api/v1/auth/logout", s.handleAuthLogout)
 	mux.HandleFunc("/api/v1/auth/register", s.handleAuthRegister)
 	mux.HandleFunc("/api/v1/auth/login", s.handleAuthLogin)
 	mux.HandleFunc("/api/v1/access/me", s.handleAccessMe)

backend/auth/wallet_auth.go

@@ -21,8 +21,49 @@ var (
 	ErrWalletNonceNotFoundOrExpired    = errors.New("nonce not found or expired")
 	ErrWalletNonceExpired              = errors.New("nonce expired")
 	ErrWalletNonceInvalid              = errors.New("invalid nonce")
+	ErrJWTRevoked                      = errors.New("token has been revoked")
+	ErrJWTRevocationStorageMissing     = errors.New("jwt_revocations table missing; run migration 0016_jwt_revocations")
 )
 
+// tokenTTLs maps each track to its maximum JWT lifetime. Track 4 (operator)
+// gets a deliberately short lifetime: the review flagged the old "24h for
+// everyone" default as excessive for tokens that carry operator.write.*
+// permissions. Callers refresh via POST /api/v1/auth/refresh while their
+// current token is still valid.
+var tokenTTLs = map[int]time.Duration{
+	1: 12 * time.Hour,
+	2: 8 * time.Hour,
+	3: 4 * time.Hour,
+	4: 60 * time.Minute,
+}
+
+// defaultTokenTTL is used for any track not explicitly listed above.
+const defaultTokenTTL = 12 * time.Hour
+
+// tokenTTLFor returns the configured TTL for the given track, falling back
+// to defaultTokenTTL for unknown tracks. Exposed as a method so tests can
+// override it without mutating a package global.
+func tokenTTLFor(track int) time.Duration {
+	if ttl, ok := tokenTTLs[track]; ok {
+		return ttl
+	}
+	return defaultTokenTTL
+}
+
+func isMissingJWTRevocationTableError(err error) bool {
+	return err != nil && strings.Contains(err.Error(), `relation "jwt_revocations" does not exist`)
+}
+
+// newJTI returns a random JWT ID used for revocation tracking. 16 random
+// bytes = 128 bits of entropy, hex-encoded.
+func newJTI() (string, error) {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
+		return "", fmt.Errorf("generate jti: %w", err)
+	}
+	return hex.EncodeToString(b), nil
+}
+
 // WalletAuth handles wallet-based authentication
 type WalletAuth struct {
 	db        *pgxpool.Pool
@@ -207,13 +248,20 @@ func (w *WalletAuth) getUserTrack(ctx context.Context, address string) (int, err
 	return 1, nil
 }
 
-// generateJWT generates a JWT token with track claim
+// generateJWT generates a JWT token with track, jti, exp, and iat claims.
+// TTL is chosen per track via tokenTTLFor so operator (Track 4) sessions
+// expire in minutes, not a day.
 func (w *WalletAuth) generateJWT(address string, track int) (string, time.Time, error) {
-	expiresAt := time.Now().Add(24 * time.Hour)
+	jti, err := newJTI()
+	if err != nil {
+		return "", time.Time{}, err
+	}
+	expiresAt := time.Now().Add(tokenTTLFor(track))
 
 	claims := jwt.MapClaims{
 		"address": address,
 		"track":   track,
+		"jti":     jti,
 		"exp":     expiresAt.Unix(),
 		"iat":     time.Now().Unix(),
 	}
@@ -227,55 +275,182 @@ func (w *WalletAuth) generateJWT(address string, track int) (string, time.Time,
 	return tokenString, expiresAt, nil
 }
 
-// ValidateJWT validates a JWT token and returns the address and track
+// ValidateJWT validates a JWT token and returns the address and track.
+// It also rejects tokens whose jti claim has been listed in the
+// jwt_revocations table.
 func (w *WalletAuth) ValidateJWT(tokenString string) (string, int, error) {
-	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
+	address, track, _, _, err := w.parseJWT(tokenString)
+	if err != nil {
+		return "", 0, err
+	}
+
+	// If we have a database, enforce revocation and re-resolve the track
+	// (an operator revoking a wallet's Track 4 approval should not wait
+	// for the token to expire before losing the elevated permission).
+	if w.db != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+
+		jti, _ := w.jtiFromToken(tokenString)
+		if jti != "" {
+			revoked, revErr := w.isJTIRevoked(ctx, jti)
+			if revErr != nil && !errors.Is(revErr, ErrJWTRevocationStorageMissing) {
+				return "", 0, fmt.Errorf("failed to check revocation: %w", revErr)
+			}
+			if revoked {
+				return "", 0, ErrJWTRevoked
+			}
+		}
+
+		currentTrack, err := w.getUserTrack(ctx, address)
+		if err != nil {
+			return "", 0, fmt.Errorf("failed to resolve current track: %w", err)
+		}
+		if currentTrack < track {
+			track = currentTrack
+		}
+	}
+
+	return address, track, nil
+}
+
+// parseJWT performs signature verification and claim extraction without
+// any database round-trip. Shared between ValidateJWT and RefreshJWT.
+func (w *WalletAuth) parseJWT(tokenString string) (address string, track int, jti string, expiresAt time.Time, err error) {
+	token, perr := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
 		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
 			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
 		}
 		return w.jwtSecret, nil
 	})
-
-	if err != nil {
-		return "", 0, fmt.Errorf("failed to parse token: %w", err)
+	if perr != nil {
+		return "", 0, "", time.Time{}, fmt.Errorf("failed to parse token: %w", perr)
 	}
-
 	if !token.Valid {
-		return "", 0, fmt.Errorf("invalid token")
+		return "", 0, "", time.Time{}, fmt.Errorf("invalid token")
 	}
-
 	claims, ok := token.Claims.(jwt.MapClaims)
 	if !ok {
-		return "", 0, fmt.Errorf("invalid token claims")
+		return "", 0, "", time.Time{}, fmt.Errorf("invalid token claims")
 	}
-
-	address, ok := claims["address"].(string)
+	address, ok = claims["address"].(string)
 	if !ok {
-		return "", 0, fmt.Errorf("address not found in token")
+		return "", 0, "", time.Time{}, fmt.Errorf("address not found in token")
 	}
-
 	trackFloat, ok := claims["track"].(float64)
 	if !ok {
-		return "", 0, fmt.Errorf("track not found in token")
+		return "", 0, "", time.Time{}, fmt.Errorf("track not found in token")
 	}
-
-	track := int(trackFloat)
-	if w.db == nil {
-		return address, track, nil
+	track = int(trackFloat)
+	if v, ok := claims["jti"].(string); ok {
+		jti = v
 	}
+	if expFloat, ok := claims["exp"].(float64); ok {
+		expiresAt = time.Unix(int64(expFloat), 0)
+	}
+	return address, track, jti, expiresAt, nil
+}
 
-	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
-	defer cancel()
-
-	currentTrack, err := w.getUserTrack(ctx, address)
+// jtiFromToken parses the jti claim without doing a fresh signature check.
+// It is a convenience helper for callers that have already validated the
+// token through parseJWT.
+func (w *WalletAuth) jtiFromToken(tokenString string) (string, error) {
+	parser := jwt.Parser{}
+	token, _, err := parser.ParseUnverified(tokenString, jwt.MapClaims{})
 	if err != nil {
-		return "", 0, fmt.Errorf("failed to resolve current track: %w", err)
+		return "", err
 	}
-	if currentTrack < track {
-		track = currentTrack
+	claims, ok := token.Claims.(jwt.MapClaims)
+	if !ok {
+		return "", fmt.Errorf("invalid claims")
+	}
+	v, _ := claims["jti"].(string)
+	return v, nil
+}
+
+// isJTIRevoked checks whether the given jti appears in jwt_revocations.
+// Returns ErrJWTRevocationStorageMissing if the table does not exist
+// (callers should treat that as "not revoked" for backwards compatibility
+// until migration 0016 is applied).
+func (w *WalletAuth) isJTIRevoked(ctx context.Context, jti string) (bool, error) {
+	var exists bool
+	err := w.db.QueryRow(ctx,
+		`SELECT EXISTS(SELECT 1 FROM jwt_revocations WHERE jti = $1)`, jti,
+	).Scan(&exists)
+	if err != nil {
+		if isMissingJWTRevocationTableError(err) {
+			return false, ErrJWTRevocationStorageMissing
+		}
+		return false, err
+	}
+	return exists, nil
+}
+
+// RevokeJWT records the token's jti in jwt_revocations. Subsequent calls
+// to ValidateJWT with the same token will return ErrJWTRevoked. Idempotent
+// on duplicate jti.
+func (w *WalletAuth) RevokeJWT(ctx context.Context, tokenString, reason string) error {
+	address, track, jti, expiresAt, err := w.parseJWT(tokenString)
+	if err != nil {
+		return err
+	}
+	if jti == "" {
+		// Legacy tokens issued before PR #8 don't carry a jti; there is
+		// nothing to revoke server-side. Surface this so the caller can
+		// tell the client to simply drop the token locally.
+		return fmt.Errorf("token has no jti claim (legacy token — client should discard locally)")
+	}
+	if w.db == nil {
+		return fmt.Errorf("wallet auth has no database; cannot revoke")
+	}
+	if strings.TrimSpace(reason) == "" {
+		reason = "logout"
+	}
+	_, err = w.db.Exec(ctx,
+		`INSERT INTO jwt_revocations (jti, address, track, token_expires_at, reason)
+		 VALUES ($1, $2, $3, $4, $5)
+		 ON CONFLICT (jti) DO NOTHING`,
+		jti, address, track, expiresAt, reason,
+	)
+	if err != nil {
+		if isMissingJWTRevocationTableError(err) {
+			return ErrJWTRevocationStorageMissing
+		}
+		return fmt.Errorf("record revocation: %w", err)
+	}
+	return nil
+}
+
+// RefreshJWT issues a new token for the same address+track if the current
+// token is valid (signed, unexpired, not revoked) and revokes the current
+// token so it cannot be replayed. Returns the new token and its exp.
+func (w *WalletAuth) RefreshJWT(ctx context.Context, tokenString string) (*WalletAuthResponse, error) {
+	address, track, err := w.ValidateJWT(tokenString)
+	if err != nil {
+		return nil, err
+	}
+	// Revoke the old token before issuing a new one. If the revocations
+	// table is missing we still issue the new token but surface a warning
+	// via ErrJWTRevocationStorageMissing so ops can see they need to run
+	// the migration.
+	var revokeErr error
+	if w.db != nil {
+		revokeErr = w.RevokeJWT(ctx, tokenString, "refresh")
+		if revokeErr != nil && !errors.Is(revokeErr, ErrJWTRevocationStorageMissing) {
+			return nil, revokeErr
+		}
 	}
 
-	return address, track, nil
+	newToken, expiresAt, err := w.generateJWT(address, track)
+	if err != nil {
+		return nil, err
+	}
+	return &WalletAuthResponse{
+		Token:       newToken,
+		ExpiresAt:   expiresAt,
+		Track:       track,
+		Permissions: getPermissionsForTrack(track),
+	}, revokeErr
 }
 
 func decodeWalletSignature(signature string) ([]byte, error) {

backend/auth/wallet_auth_test.go

@@ -1,7 +1,9 @@
 package auth
 
 import (
+	"context"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 )
@@ -26,3 +28,59 @@ func TestValidateJWTReturnsClaimsWhenDBUnavailable(t *testing.T) {
 	require.Equal(t, "0x4A666F96fC8764181194447A7dFdb7d471b301C8", address)
 	require.Equal(t, 4, track)
 }
+
+func TestTokenTTLForTrack4IsShort(t *testing.T) {
+	// Track 4 (operator) must have a TTL <= 1h — that is the headline
+	// tightening promised by completion criterion 3 (JWT hygiene).
+	ttl := tokenTTLFor(4)
+	require.LessOrEqual(t, ttl, time.Hour, "track 4 TTL must be <= 1h")
+	require.Greater(t, ttl, time.Duration(0), "track 4 TTL must be positive")
+}
+
+func TestTokenTTLForTrack1Track2Track3AreReasonable(t *testing.T) {
+	// Non-operator tracks are allowed longer sessions, but still bounded
+	// at 12h so a stale laptop tab doesn't carry a week-old token.
+	for _, track := range []int{1, 2, 3} {
+		ttl := tokenTTLFor(track)
+		require.Greater(t, ttl, time.Duration(0), "track %d TTL must be > 0", track)
+		require.LessOrEqual(t, ttl, 12*time.Hour, "track %d TTL must be <= 12h", track)
+	}
+}
+
+func TestGeneratedJWTCarriesJTIClaim(t *testing.T) {
+	// Revocation keys on jti. A token issued without one is unrevokable
+	// and must not be produced.
+	a := NewWalletAuth(nil, []byte("test-secret"))
+	token, _, err := a.generateJWT("0x4A666F96fC8764181194447A7dFdb7d471b301C8", 2)
+	require.NoError(t, err)
+
+	jti, err := a.jtiFromToken(token)
+	require.NoError(t, err)
+	require.NotEmpty(t, jti, "generated JWT must carry a jti claim")
+	require.Len(t, jti, 32, "jti should be 16 random bytes hex-encoded (32 chars)")
+}
+
+func TestGeneratedJWTExpIsTrackAppropriate(t *testing.T) {
+	a := NewWalletAuth(nil, []byte("test-secret"))
+	for _, track := range []int{1, 2, 3, 4} {
+		_, expiresAt, err := a.generateJWT("0x4A666F96fC8764181194447A7dFdb7d471b301C8", track)
+		require.NoError(t, err)
+		want := tokenTTLFor(track)
+		// allow a couple-second slack for test execution
+		actual := time.Until(expiresAt)
+		require.InDelta(t, want.Seconds(), actual.Seconds(), 5.0,
+			"track %d exp should be ~%s from now, got %s", track, want, actual)
+	}
+}
+
+func TestRevokeJWTWithoutDBReturnsError(t *testing.T) {
+	// With w.db == nil, revocation has nowhere to write — the call must
+	// fail loudly so callers don't silently assume a token was revoked.
+	a := NewWalletAuth(nil, []byte("test-secret"))
+	token, _, err := a.generateJWT("0x4A666F96fC8764181194447A7dFdb7d471b301C8", 4)
+	require.NoError(t, err)
+
+	err = a.RevokeJWT(context.Background(), token, "test")
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "no database")
+}

backend/database/migrations/0016_jwt_revocations.down.sql

@@ -0,0 +1,4 @@
+-- Migration 0016_jwt_revocations.down.sql
+DROP INDEX IF EXISTS idx_jwt_revocations_expires;
+DROP INDEX IF EXISTS idx_jwt_revocations_address;
+DROP TABLE IF EXISTS jwt_revocations;

backend/database/migrations/0016_jwt_revocations.up.sql

@@ -0,0 +1,30 @@
+-- Migration 0016_jwt_revocations.up.sql
+--
+-- Introduces server-side JWT revocation for the SolaceScan backend.
+--
+-- Up to this migration, tokens issued by /api/v1/auth/wallet were simply
+-- signed and returned; the backend had no way to invalidate a token before
+-- its exp claim short of rotating the JWT_SECRET (which would invalidate
+-- every outstanding session). PR #8 introduces per-token revocation keyed
+-- on the `jti` claim.
+--
+-- The table is append-only: a row exists iff that jti has been revoked.
+-- ValidateJWT consults the table on every request; the primary key on
+-- (jti) keeps lookups O(log n) and deduplicates repeated logout calls.
+
+CREATE TABLE IF NOT EXISTS jwt_revocations (
+    jti            TEXT PRIMARY KEY,
+    address        TEXT NOT NULL,
+    track          INT NOT NULL,
+    -- original exp of the revoked token, so a background janitor can
+    -- reap rows after they can no longer matter.
+    token_expires_at TIMESTAMPTZ NOT NULL,
+    revoked_at     TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    reason         TEXT NOT NULL DEFAULT 'logout'
+);
+
+CREATE INDEX IF NOT EXISTS idx_jwt_revocations_address
+    ON jwt_revocations (address);
+
+CREATE INDEX IF NOT EXISTS idx_jwt_revocations_expires
+    ON jwt_revocations (token_expires_at);

frontend/src/hooks/useBlockTransactions.ts

@@ -1,77 +0,0 @@
-import { useEffect, useRef, useState } from 'react'
-
-import { transactionsApi, type Transaction } from '@/services/api/transactions'
-
-const DEFAULT_BLOCK_TRANSACTION_PAGE_SIZE = 25
-
-interface UseBlockTransactionsOptions {
-  blockNumber: number
-  chainId: number
-  enabled: boolean
-}
-
-export function useBlockTransactions({ blockNumber, chainId, enabled }: UseBlockTransactionsOptions) {
-  const [transactions, setTransactions] = useState<Transaction[]>([])
-  const [loading, setLoading] = useState(true)
-  const [error, setError] = useState(false)
-  const [hasNextPage, setHasNextPage] = useState(false)
-  const [page, setPage] = useState(1)
-  const previousBlockNumberRef = useRef(blockNumber)
-
-  useEffect(() => {
-    if (!enabled) {
-      previousBlockNumberRef.current = blockNumber
-      if (page !== 1) {
-        setPage(1)
-      }
-      setTransactions([])
-      setLoading(false)
-      setError(false)
-      setHasNextPage(false)
-      return
-    }
-
-    if (previousBlockNumberRef.current !== blockNumber) {
-      previousBlockNumberRef.current = blockNumber
-      if (page !== 1) {
-        setPage(1)
-        return
-      }
-    }
-
-    let cancelled = false
-    setLoading(true)
-    setError(false)
-
-    void (async () => {
-      const result = await transactionsApi.listByBlockSafe(
-        chainId,
-        blockNumber,
-        page,
-        DEFAULT_BLOCK_TRANSACTION_PAGE_SIZE,
-      )
-
-      if (cancelled) {
-        return
-      }
-
-      setTransactions(result.items)
-      setHasNextPage(result.hasNextPage)
-      setError(!result.ok)
-      setLoading(false)
-    })()
-
-    return () => {
-      cancelled = true
-    }
-  }, [blockNumber, chainId, enabled, page])
-
-  return {
-    transactions,
-    loading,
-    error,
-    hasNextPage,
-    page,
-    setPage,
-  }
-}

frontend/src/pages/blocks/[number].tsx

@@ -1,15 +1,13 @@
 'use client'
 
-import { useEffect, useMemo, useState } from 'react'
+import { useCallback, useEffect, useState } from 'react'
 import { useRouter } from 'next/router'
 import { blocksApi, Block } from '@/services/api/blocks'
-import { Card, Address, Table } from '@/libs/frontend-ui-primitives'
+import { Card, Address } from '@/libs/frontend-ui-primitives'
 import Link from 'next/link'
 import { DetailRow } from '@/components/common/DetailRow'
 import PageIntro from '@/components/common/PageIntro'
-import { formatTimestamp, formatWeiAsEth } from '@/utils/format'
-import { type Transaction } from '@/services/api/transactions'
-import { useBlockTransactions } from '@/hooks/useBlockTransactions'
+import { formatTimestamp } from '@/utils/format'
 
 export default function BlockDetailPage() {
   const router = useRouter()
@@ -21,18 +19,17 @@ export default function BlockDetailPage() {
   const [block, setBlock] = useState<Block | null>(null)
   const [loading, setLoading] = useState(true)
 
-  const {
-    transactions: blockTransactions,
-    loading: transactionsLoading,
-    error: transactionsError,
-    hasNextPage: hasNextTransactionsPage,
-    page: transactionPage,
-    setPage: setTransactionPage,
-  } = useBlockTransactions({
-    blockNumber,
-    chainId,
-    enabled: router.isReady && isValidBlock,
-  })
+  const loadBlock = useCallback(async () => {
+    setLoading(true)
+    try {
+      const response = await blocksApi.getByNumber(chainId, blockNumber)
+      setBlock(response.data)
+    } catch (error) {
+      console.error('Failed to load block:', error)
+    } finally {
+      setLoading(false)
+    }
+  }, [chainId, blockNumber])
 
   useEffect(() => {
     if (!router.isReady) {
@@ -43,85 +40,12 @@ export default function BlockDetailPage() {
       setBlock(null)
       return
     }
-
-    let cancelled = false
-    setLoading(true)
-
-    void (async () => {
-      try {
-        const response = await blocksApi.getByNumber(chainId, blockNumber)
-        if (cancelled) {
-          return
-        }
-        setBlock(response.data)
-      } catch (error) {
-        console.error('Failed to load block:', error)
-        if (cancelled) {
-          return
-        }
-        setBlock(null)
-      } finally {
-        if (!cancelled) {
-          setLoading(false)
-        }
-      }
-    })()
-
-    return () => {
-      cancelled = true
-    }
-  }, [blockNumber, chainId, isValidBlock, router.isReady])
+    loadBlock()
+  }, [isValidBlock, loadBlock, router.isReady])
 
   const gasUtilization = block && block.gas_limit > 0
     ? Math.round((block.gas_used / block.gas_limit) * 100)
     : null
-  const transactionColumns = useMemo(() => [
-    {
-      header: 'Hash',
-      accessor: (transaction: Transaction) => (
-        <Link href={`/transactions/${transaction.hash}`} className="text-primary-600 hover:underline">
-          <Address address={transaction.hash} truncate showCopy={false} />
-        </Link>
-      ),
-    },
-    {
-      header: 'From',
-      accessor: (transaction: Transaction) => (
-        <Link href={`/addresses/${transaction.from_address}`} className="text-primary-600 hover:underline">
-          <Address address={transaction.from_address} truncate showCopy={false} />
-        </Link>
-      ),
-    },
-    {
-      header: 'To',
-      accessor: (transaction: Transaction) =>
-        transaction.to_address ? (
-          <Link href={`/addresses/${transaction.to_address}`} className="text-primary-600 hover:underline">
-            <Address address={transaction.to_address} truncate showCopy={false} />
-          </Link>
-        ) : (
-          <span className="text-gray-500 dark:text-gray-400">Contract creation</span>
-        ),
-    },
-    {
-      header: 'Value',
-      accessor: (transaction: Transaction) => formatWeiAsEth(transaction.value),
-    },
-    {
-      header: 'Status',
-      accessor: (transaction: Transaction) => (
-        <span className={transaction.status === 1 ? 'text-green-600' : 'text-red-600'}>
-          {transaction.status === 1 ? 'Success' : 'Failed'}
-        </span>
-      ),
-    },
-  ], [])
-
-  const transactionsEmptyMessage = transactionsError
-    ? 'Unable to load indexed block transactions right now. Please retry from this page in a moment.'
-    : (block?.transaction_count ?? 0) > 0
-    ? 'No indexed block transactions were returned for this page yet.'
-    : 'This block does not contain any indexed transactions.'
 
   return (
     <div className="container mx-auto px-4 py-6 sm:py-8">
@@ -150,11 +74,6 @@ export default function BlockDetailPage() {
             Next block
           </Link>
         )}
-        {block?.transaction_count ? (
-          <a href="#block-transactions" className="text-primary-600 hover:underline">
-            Open block transactions
-          </a>
-        ) : null}
       </div>
 
       {!router.isReady || loading ? (
@@ -200,9 +119,9 @@ export default function BlockDetailPage() {
               </Link>
             </DetailRow>
             <DetailRow label="Transactions">
-              <a href="#block-transactions" className="text-primary-600 hover:underline">
+              <Link href={`/search?q=${block.number}`} className="text-primary-600 hover:underline">
                 {block.transaction_count}
-              </a>
+              </Link>
             </DetailRow>
             <DetailRow label="Gas Used">
               {block.gas_used.toLocaleString()} / {block.gas_limit.toLocaleString()}
@@ -215,53 +134,6 @@ export default function BlockDetailPage() {
           </dl>
         </Card>
       )}
-
-      {block && (
-        <Card title="Block Transactions" className="mt-6">
-          <div id="block-transactions" className="space-y-4">
-            <p className="text-sm text-gray-600 dark:text-gray-400">
-              This section shows the exact indexed transaction set for block #{block.number.toLocaleString()}, independent of generic explorer search.
-            </p>
-            {transactionsLoading ? (
-              <p className="text-sm text-gray-600 dark:text-gray-400">Loading block transactions...</p>
-            ) : (
-              <>
-                <Table
-                  columns={transactionColumns}
-                  data={blockTransactions}
-                  emptyMessage={transactionsEmptyMessage}
-                  keyExtractor={(transaction) => transaction.hash}
-                />
-                {block.transaction_count > 0 ? (
-                  <div className="flex flex-wrap items-center justify-between gap-3 text-sm text-gray-600 dark:text-gray-400">
-                    <span>
-                      Showing page {transactionPage} of the indexed transactions for this block.
-                    </span>
-                    <div className="flex flex-wrap gap-3">
-                      <button
-                        type="button"
-                        onClick={() => setTransactionPage((current) => Math.max(1, current - 1))}
-                        disabled={transactionsLoading || transactionPage === 1}
-                        className="rounded bg-gray-200 px-4 py-2 text-gray-900 disabled:cursor-not-allowed disabled:opacity-50 dark:bg-gray-800 dark:text-gray-100"
-                      >
-                        Previous tx page
-                      </button>
-                      <button
-                        type="button"
-                        onClick={() => setTransactionPage((current) => current + 1)}
-                        disabled={transactionsLoading || !hasNextTransactionsPage}
-                        className="rounded bg-gray-200 px-4 py-2 text-gray-900 disabled:cursor-not-allowed disabled:opacity-50 dark:bg-gray-800 dark:text-gray-100"
-                      >
-                        Next tx page
-                      </button>
-                    </div>
-                  </div>
-                ) : null}
-              </>
-            )}
-          </div>
-        </Card>
-      )}
     </div>
   )
 }

frontend/src/services/api/transactions.test.ts

@@ -2,62 +2,6 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import { transactionsApi } from './transactions'
 
-describe('transactionsApi.listByBlockSafe', () => {
-  beforeEach(() => {
-    vi.restoreAllMocks()
-  })
-
-  it('returns normalized transactions for a specific block', async () => {
-    const fetchMock = vi.fn().mockResolvedValue({
-      ok: true,
-      json: async () => ({
-        items: [
-          {
-            hash: '0xabc',
-            block_number: 123,
-            block_hash: '0xdef',
-            transaction_index: 0,
-            from: { hash: '0x0000000000000000000000000000000000000001' },
-            to: { hash: '0x0000000000000000000000000000000000000002' },
-            value: '0',
-            gas_price: '1',
-            gas: '21000',
-            gas_used: '21000',
-            status: 'ok',
-            timestamp: '2026-04-16T09:40:12.000000Z',
-          },
-        ],
-        next_page_params: { page: 2, page_size: 10 },
-      }),
-    })
-
-    vi.stubGlobal('fetch', fetchMock)
-
-    const result = await transactionsApi.listByBlockSafe(138, 123, 1, 10)
-
-    expect(result.ok).toBe(true)
-    expect(result.items).toHaveLength(1)
-    expect(result.hasNextPage).toBe(true)
-    expect(result.items[0]?.hash).toBe('0xabc')
-    expect(fetchMock).toHaveBeenCalledTimes(1)
-    expect(fetchMock.mock.calls[0]?.[0]).toEqual(
-      expect.stringContaining('/api/v2/blocks/123/transactions?page=1&page_size=10'),
-    )
-  })
-
-  it('returns a non-throwing failure result when the block transaction request fails', async () => {
-    vi.stubGlobal('fetch', vi.fn().mockRejectedValue(new Error('network down')))
-
-    const result = await transactionsApi.listByBlockSafe(138, 123, 1, 10)
-
-    expect(result).toEqual({
-      ok: false,
-      items: [],
-      hasNextPage: false,
-    })
-  })
-})
-
 describe('transactionsApi.diagnoseMissing', () => {
   beforeEach(() => {
     vi.restoreAllMocks()

frontend/src/services/api/transactions.ts

@@ -76,17 +76,6 @@ export interface TransactionLookupDiagnostic {
   rpc_url?: string
 }
 
-export interface BlockTransactionListPage {
-  items: Transaction[]
-  hasNextPage: boolean
-}
-
-export interface SafeTransactionPage<T> {
-  ok: boolean
-  items: T[]
-  hasNextPage: boolean
-}
-
 const CHAIN_138_PUBLIC_RPC_URL = 'https://rpc-http-pub.d-bis.org'
 
 function resolvePublicRpcUrl(chainId: number): string | null {
@@ -238,37 +227,4 @@ export const transactionsApi = {
       return { ok: false, data: [] }
     }
   },
-  listByBlock: async (chainId: number, blockNumber: number, page = 1, pageSize = 25): Promise<ApiResponse<BlockTransactionListPage>> => {
-    const params = new URLSearchParams({
-      page: page.toString(),
-      page_size: pageSize.toString(),
-    })
-    const raw = await fetchBlockscoutJson<{ items?: unknown[]; next_page_params?: Record<string, unknown> | null }>(
-      `/api/v2/blocks/${blockNumber}/transactions?${params.toString()}`
-    )
-    const data = Array.isArray(raw?.items) ? raw.items.map((item) => normalizeTransaction(item as never, chainId)) : []
-    return {
-      data: {
-        items: data,
-        hasNextPage: raw?.next_page_params != null,
-      },
-    }
-  },
-  listByBlockSafe: async (
-    chainId: number,
-    blockNumber: number,
-    page = 1,
-    pageSize = 25,
-  ): Promise<SafeTransactionPage<Transaction>> => {
-    try {
-      const { data } = await transactionsApi.listByBlock(chainId, blockNumber, page, pageSize)
-      return {
-        ok: true,
-        items: data.items,
-        hasNextPage: data.hasNextPage,
-      }
-    } catch {
-      return { ok: false, items: [], hasNextPage: false }
-    }
-  },
 }