feat: add persistent stale-while-revalidate API cache

Introduce an actor-backed persistent cache layer at the SRHTClient boundary
for read-only SourceHut data. Cache entries now store stable metadata
including key, resource type, fetched/expires/access timestamps, payload
hash, schema version, and payload size, with bounded memory and disk usage.

Add centralized cache key builders and TTL defaults for repository, file,
ticket, build, log, profile, status, and list-style resources. Support
networkOnly, cacheOnly, cacheFirstThenRefresh, and refreshIgnoringCache
policies, plus request coalescing for duplicate in-flight cache keys.

Integrate first-pass caching into high-value low-risk read paths:
- build detail and completed/active build logs
- ticket detail
- README lookup
- repository tree, blob, and linked file reads

Keep mutation paths network-only and add simple prefix invalidation after
ticket and build mutations. Add compact cached/stale UI status rows and a
Settings action to clear the persistent cache.

Add focused cache tests covering round trips, expiration, stale fallback,
policy behavior, request coalescing, prefix invalidation, size limits, LRU
pruning, expired pruning, and mutation bypass behavior. Document storage,
key, TTL, invalidation, limitations, and next recommended targets.

12 files changed, 1030 insertions, 86 deletions

diff --git a/Hutch/App/AppState.swift b/Hutch/App/AppState.swift
index ebd25d1..f91f1a4 100644
--- a/Hutch/App/AppState.swift
+++ b/Hutch/App/AppState.swift
@@ -212,6 +212,7 @@ final class AppState {
         clearActiveSessionState()
         try? KeychainHelper.deleteAll()
         URLCache.shared.removeAllCachedResponses()
+        await client.clearPersistentCache()
         HTTPCookieStorage.shared.cookies?.forEach { HTTPCookieStorage.shared.deleteCookie($0) }
         await clearWebData()
         clearWebContentRenderCaches()
@@ -232,6 +233,7 @@ final class AppState {
         }
         try? KeychainHelper.deleteAll()
         URLCache.shared.removeAllCachedResponses()
+        await client.clearPersistentCache()
         HTTPCookieStorage.shared.cookies?.forEach { HTTPCookieStorage.shared.deleteCookie($0) }
         await clearWebData()
         clearWebContentRenderCaches()
@@ -450,7 +452,10 @@ final class AppState {
     }
 
     private func makeSession(for account: AccountEntry, knownUser: User? = nil) async throws -> AccountSession {
-        let sessionClient = SRHTClient(token: account.token)
+        let sessionClient = SRHTClient(
+            token: account.token,
+            cache: PersistentAPICache(configuration: .accountScoped(accountID: account.id))
+        )
         let user: User
         if let knownUser {
             user = knownUser
diff --git a/Hutch/Networking/APICache.swift b/Hutch/Networking/APICache.swift
new file mode 100644
index 0000000..9c1a262
--- /dev/null
+++ b/Hutch/Networking/APICache.swift
@@ -0,0 +1,337 @@
+import CryptoKit
+import Foundation
+
+enum CachePolicy: Sendable, Equatable {
+    case networkOnly
+    case cacheOnly
+    case cacheFirstThenRefresh
+    case refreshIgnoringCache
+}
+
+enum CacheResourceType: String, Codable, Sendable {
+    case repositoryDetail
+    case repositoryList
+    case repositoryTree
+    case repositoryFile
+    case repositoryReadme
+    case ticketDetail
+    case ticketList
+    case buildDetail
+    case buildList
+    case buildLog
+    case userProfile
+    case status
+    case pasteList
+    case debug
+}
+
+struct CacheEntryMetadata: Codable, Sendable, Equatable {
+    let cacheKey: String
+    let resourceType: CacheResourceType
+    let fetchedAt: Date
+    let expiresAt: Date
+    var lastAccessedAt: Date
+    let payloadHash: String
+    let schemaVersion: Int
+    let payloadSize: Int
+
+    func isExpired(now: Date = Date()) -> Bool {
+        expiresAt <= now
+    }
+}
+
+struct APICacheEntry: Sendable {
+    var metadata: CacheEntryMetadata
+    let payload: Data
+}
+
+struct CachedValue<Value> {
+    let value: Value
+    let metadata: CacheEntryMetadata?
+    let source: CacheValueSource
+
+    var isFromCache: Bool { source == .cache }
+    var isStale: Bool { metadata?.isExpired() ?? false }
+}
+
+enum CacheValueSource: Sendable, Equatable {
+    case cache
+    case network
+}
+
+enum APICacheError: LocalizedError, Sendable {
+    case miss
+    case entryTooLarge(Int)
+    case cacheTooLarge
+
+    var errorDescription: String? {
+        switch self {
+        case .miss:
+            "No cached data is available."
+        case .entryTooLarge(let bytes):
+            "The response is too large to cache (\(bytes) bytes)."
+        case .cacheTooLarge:
+            "The cache size limit was exceeded."
+        }
+    }
+}
+
+struct APICacheConfiguration: Sendable {
+    var directory: URL
+    var maxCacheSizeBytes: Int
+    var maxEntrySizeBytes: Int
+    var memoryEntryLimit: Int
+    var schemaVersion: Int
+
+    static func accountScoped(accountID: String) -> APICacheConfiguration {
+        let base = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first
+            ?? URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
+        return APICacheConfiguration(
+            directory: base
+                .appendingPathComponent("Hutch", isDirectory: true)
+                .appendingPathComponent("APICache", isDirectory: true)
+                .appendingPathComponent(accountID, isDirectory: true),
+            maxCacheSizeBytes: 50 * 1024 * 1024,
+            maxEntrySizeBytes: 2 * 1024 * 1024,
+            memoryEntryLimit: 64,
+            schemaVersion: 1
+        )
+    }
+
+    static func temporary(directory: URL) -> APICacheConfiguration {
+        APICacheConfiguration(
+            directory: directory,
+            maxCacheSizeBytes: 4 * 1024 * 1024,
+            maxEntrySizeBytes: 512 * 1024,
+            memoryEntryLimit: 16,
+            schemaVersion: 1
+        )
+    }
+}
+
+protocol APICache: Sendable {
+    func read(cacheKey: String) async throws -> APICacheEntry
+    func write(payload: Data, cacheKey: String, resourceType: CacheResourceType, ttl: TimeInterval) async throws -> CacheEntryMetadata
+    func remove(cacheKey: String) async
+    func removeByPrefix(_ prefix: String) async
+    func clearAll() async
+    func pruneExpired(now: Date) async
+    func pruneToSizeLimit() async
+}
+
+actor PersistentAPICache: APICache {
+    private struct StoredEntry: Codable, Sendable {
+        var metadata: CacheEntryMetadata
+        let payload: Data
+    }
+
+    private let configuration: APICacheConfiguration
+    private let fileManager: FileManager
+    private var memoryEntries: [String: APICacheEntry] = [:]
+    private var memoryOrder: [String] = []
+    private var knownMetadata: [String: CacheEntryMetadata] = [:]
+    private var writeCountSincePrune = 0
+
+    init(configuration: APICacheConfiguration, fileManager: FileManager = .default) {
+        self.configuration = configuration
+        self.fileManager = fileManager
+    }
+
+    func read(cacheKey: String) async throws -> APICacheEntry {
+        if var entry = memoryEntries[cacheKey] {
+            entry.metadata.lastAccessedAt = Date()
+            memoryEntries[cacheKey] = entry
+            markMemoryUse(cacheKey)
+            try? persist(entry)
+            return entry
+        }
+
+        let url = fileURL(for: cacheKey)
+        guard fileManager.fileExists(atPath: url.path) else {
+            throw APICacheError.miss
+        }
+
+        var stored = try decodeEntry(from: url)
+        guard stored.metadata.schemaVersion == configuration.schemaVersion else {
+            try? fileManager.removeItem(at: url)
+            throw APICacheError.miss
+        }
+
+        stored.metadata.lastAccessedAt = Date()
+        let entry = APICacheEntry(metadata: stored.metadata, payload: stored.payload)
+        knownMetadata[cacheKey] = stored.metadata
+        remember(entry)
+        try? persist(entry)
+        return entry
+    }
+
+    func write(
+        payload: Data,
+        cacheKey: String,
+        resourceType: CacheResourceType,
+        ttl: TimeInterval
+    ) async throws -> CacheEntryMetadata {
+        guard payload.count <= configuration.maxEntrySizeBytes else {
+            throw APICacheError.entryTooLarge(payload.count)
+        }
+
+        try ensureDirectoryExists()
+        let now = Date()
+        let payloadHash = Self.payloadHash(payload)
+        if let existing = try? await read(cacheKey: cacheKey),
+           existing.metadata.payloadHash == payloadHash {
+            let metadata = CacheEntryMetadata(
+                cacheKey: cacheKey,
+                resourceType: resourceType,
+                fetchedAt: now,
+                expiresAt: now.addingTimeInterval(ttl),
+                lastAccessedAt: now,
+                payloadHash: payloadHash,
+                schemaVersion: configuration.schemaVersion,
+                payloadSize: payload.count
+            )
+            let entry = APICacheEntry(metadata: metadata, payload: payload)
+            remember(entry)
+            try persist(entry)
+            return metadata
+        }
+
+        let metadata = CacheEntryMetadata(
+            cacheKey: cacheKey,
+            resourceType: resourceType,
+            fetchedAt: now,
+            expiresAt: now.addingTimeInterval(ttl),
+            lastAccessedAt: now,
+            payloadHash: payloadHash,
+            schemaVersion: configuration.schemaVersion,
+            payloadSize: payload.count
+        )
+        let entry = APICacheEntry(metadata: metadata, payload: payload)
+        remember(entry)
+        try persist(entry)
+
+        writeCountSincePrune += 1
+        if writeCountSincePrune >= 12 {
+            writeCountSincePrune = 0
+            await pruneExpired(now: now)
+            await pruneToSizeLimit()
+        }
+        return metadata
+    }
+
+    func remove(cacheKey: String) async {
+        memoryEntries.removeValue(forKey: cacheKey)
+        memoryOrder.removeAll { $0 == cacheKey }
+        knownMetadata.removeValue(forKey: cacheKey)
+        try? fileManager.removeItem(at: fileURL(for: cacheKey))
+    }
+
+    func removeByPrefix(_ prefix: String) async {
+        await loadKnownMetadataIfNeeded()
+        for key in knownMetadata.keys where key.hasPrefix(prefix) {
+            await remove(cacheKey: key)
+        }
+    }
+
+    func clearAll() async {
+        memoryEntries.removeAll()
+        memoryOrder.removeAll()
+        knownMetadata.removeAll()
+        try? fileManager.removeItem(at: configuration.directory)
+    }
+
+    func pruneExpired(now: Date = Date()) async {
+        await loadKnownMetadataIfNeeded()
+        for metadata in knownMetadata.values where metadata.isExpired(now: now) {
+            await remove(cacheKey: metadata.cacheKey)
+        }
+    }
+
+    func pruneToSizeLimit() async {
+        await loadKnownMetadataIfNeeded()
+        var totalSize = knownMetadata.values.reduce(0) { $0 + $1.payloadSize }
+        guard totalSize > configuration.maxCacheSizeBytes else { return }
+
+        let victims = knownMetadata.values.sorted { $0.lastAccessedAt < $1.lastAccessedAt }
+        for metadata in victims {
+            await remove(cacheKey: metadata.cacheKey)
+            totalSize -= metadata.payloadSize
+            if totalSize <= configuration.maxCacheSizeBytes { break }
+        }
+    }
+
+    private func remember(_ entry: APICacheEntry) {
+        memoryEntries[entry.metadata.cacheKey] = entry
+        knownMetadata[entry.metadata.cacheKey] = entry.metadata
+        markMemoryUse(entry.metadata.cacheKey)
+        while memoryOrder.count > configuration.memoryEntryLimit, let evicted = memoryOrder.first {
+            memoryOrder.removeFirst()
+            memoryEntries.removeValue(forKey: evicted)
+        }
+    }
+
+    private func markMemoryUse(_ cacheKey: String) {
+        memoryOrder.removeAll { $0 == cacheKey }
+        memoryOrder.append(cacheKey)
+    }
+
+    private func persist(_ entry: APICacheEntry) throws {
+        try ensureDirectoryExists()
+        let stored = StoredEntry(metadata: entry.metadata, payload: entry.payload)
+        let data = try JSONEncoder.srhtCache.encode(stored)
+        try data.write(to: fileURL(for: entry.metadata.cacheKey), options: [.atomic])
+    }
+
+    private func decodeEntry(from url: URL) throws -> StoredEntry {
+        let data = try Data(contentsOf: url)
+        return try JSONDecoder.srhtCache.decode(StoredEntry.self, from: data)
+    }
+
+    private func loadKnownMetadataIfNeeded() async {
+        guard knownMetadata.isEmpty else { return }
+        guard let urls = try? fileManager.contentsOfDirectory(
+            at: configuration.directory,
+            includingPropertiesForKeys: nil
+        ) else { return }
+
+        for url in urls where url.pathExtension == "json" {
+            guard let stored = try? decodeEntry(from: url) else { continue }
+            knownMetadata[stored.metadata.cacheKey] = stored.metadata
+        }
+    }
+
+    private func ensureDirectoryExists() throws {
+        if !fileManager.fileExists(atPath: configuration.directory.path) {
+            try fileManager.createDirectory(
+                at: configuration.directory,
+                withIntermediateDirectories: true
+            )
+        }
+    }
+
+    private func fileURL(for cacheKey: String) -> URL {
+        configuration.directory
+            .appendingPathComponent(Self.payloadHash(Data(cacheKey.utf8)))
+            .appendingPathExtension("json")
+    }
+
+    private static func payloadHash(_ data: Data) -> String {
+        SHA256.hash(data: data).map { String(format: "%02x", $0) }.joined()
+    }
+}
+
+extension JSONEncoder {
+    static var srhtCache: JSONEncoder {
+        let encoder = JSONEncoder()
+        encoder.dateEncodingStrategy = .iso8601
+        return encoder
+    }
+}
+
+extension JSONDecoder {
+    static var srhtCache: JSONDecoder {
+        let decoder = JSONDecoder()
+        decoder.dateDecodingStrategy = .iso8601
+        return decoder
+    }
+}
diff --git a/Hutch/Networking/APICacheKeys.swift b/Hutch/Networking/APICacheKeys.swift
new file mode 100644
index 0000000..5e57a51
--- /dev/null
+++ b/Hutch/Networking/APICacheKeys.swift
@@ -0,0 +1,105 @@
+import Foundation
+
+enum APICacheKeys {
+    static func repositories(service: SRHTService, owner: String? = nil, cursor: String? = nil, filter: String? = nil) -> String {
+        make([
+            service.rawValue,
+            "repositories",
+            owner.map { "owner:\(normalize($0))" },
+            cursor.map { "cursor:\($0)" },
+            filter.map { "filter:\(normalize($0))" }
+        ])
+    }
+
+    static func repository(service: SRHTService, owner: String, name: String) -> String {
+        make([service.rawValue, "repository", normalize(owner), normalize(name)])
+    }
+
+    static func repositoryRID(service: SRHTService, rid: String) -> String {
+        make([service.rawValue, "repository", "rid:\(rid)"])
+    }
+
+    static func refs(service: SRHTService, rid: String, cursor: String? = nil) -> String {
+        make([service.rawValue, "refs", "rid:\(rid)", cursor.map { "cursor:\($0)" }])
+    }
+
+    static func readme(service: SRHTService, rid: String, path: String? = nil, ref: String = "HEAD") -> String {
+        make([service.rawValue, "readme", "rid:\(rid)", "ref:\(ref)", path.map { "path:\($0)" }])
+    }
+
+    static func treeRoot(service: SRHTService, rid: String, ref: String) -> String {
+        make([service.rawValue, "tree", "rid:\(rid)", "ref:\(ref)", "root"])
+    }
+
+    static func treeEntries(service: SRHTService, rid: String, treeId: String, cursor: String? = nil) -> String {
+        make([service.rawValue, "tree", "rid:\(rid)", "tree:\(treeId)", cursor.map { "cursor:\($0)" }])
+    }
+
+    static func blob(service: SRHTService, rid: String, blobId: String) -> String {
+        make([service.rawValue, "blob", "rid:\(rid)", "blob:\(blobId)"])
+    }
+
+    static func path(service: SRHTService, rid: String, ref: String, path: String) -> String {
+        make([service.rawValue, "path", "rid:\(rid)", "ref:\(ref)", "path:\(path)"])
+    }
+
+    static func ticketDetail(owner: String, trackerRid: String, ticketId: Int) -> String {
+        make([SRHTService.todo.rawValue, "ticket", normalize(owner), "tracker:\(trackerRid)", "ticket:\(ticketId)"])
+    }
+
+    static func trackerLabels(trackerRid: String) -> String {
+        make([SRHTService.todo.rawValue, "tracker-labels", "tracker:\(trackerRid)"])
+    }
+
+    static func builds(cursor: String? = nil, filter: String? = nil) -> String {
+        make([SRHTService.builds.rawValue, "jobs", cursor.map { "cursor:\($0)" }, filter.map { "filter:\($0)" }])
+    }
+
+    static func buildDetail(jobId: Int) -> String {
+        make([SRHTService.builds.rawValue, "job", "id:\(jobId)"])
+    }
+
+    static func buildLog(url: URL, jobId: Int? = nil, task: String? = nil) -> String {
+        make([SRHTService.builds.rawValue, "log", jobId.map { "job:\($0)" }, task.map { "task:\($0)" }, url.absoluteString])
+    }
+
+    static func userRepositories(owner: String, cursor: String? = nil) -> String {
+        make([SRHTService.git.rawValue, "user-repositories", normalize(owner), cursor.map { "cursor:\($0)" }])
+    }
+
+    static func userTrackers(owner: String, cursor: String? = nil) -> String {
+        make([SRHTService.todo.rawValue, "user-trackers", normalize(owner), cursor.map { "cursor:\($0)" }])
+    }
+
+    static func pasteList(cursor: String? = nil) -> String {
+        make([SRHTService.paste.rawValue, "pastes", cursor.map { "cursor:\($0)" }])
+    }
+
+    static func prefix(_ components: String...) -> String {
+        make(components)
+    }
+
+    private static func make(_ parts: [String?]) -> String {
+        parts.compactMap { $0?.replacingOccurrences(of: "|", with: "%7C") }
+            .joined(separator: "|")
+    }
+
+    private static func normalize(_ value: String) -> String {
+        value.trimmingCharacters(in: .whitespacesAndNewlines).lowercased()
+    }
+}
+
+enum APICacheTTLs {
+    // Active build data changes quickly; completed logs and content-addressed git data are effectively immutable.
+    static let activeBuild: TimeInterval = 15
+    static let completedBuildDetail: TimeInterval = 60 * 60
+    static let completedBuildLog: TimeInterval = 30 * 24 * 60 * 60
+    static let ticketDetail: TimeInterval = 5 * 60
+    static let ticketList: TimeInterval = 2 * 60
+    static let repositoryMetadata: TimeInterval = 30 * 60
+    static let repositoryList: TimeInterval = 5 * 60
+    static let immutableFileContent: TimeInterval = 14 * 24 * 60 * 60
+    static let movingRefFileContent: TimeInterval = 10 * 60
+    static let userProfile: TimeInterval = 30 * 60
+    static let status: TimeInterval = 5 * 60
+}
diff --git a/Hutch/Networking/SRHTClient.swift b/Hutch/Networking/SRHTClient.swift
index b4f8ee0..37fd6b8 100644
--- a/Hutch/Networking/SRHTClient.swift
+++ b/Hutch/Networking/SRHTClient.swift
@@ -1,3 +1,4 @@
+import CryptoKit
 import Foundation
 import os
 
@@ -20,6 +21,8 @@ final class SRHTClient: Sendable {
     private let session: URLSession
     private let decoder: JSONDecoder
     private let encoder: JSONEncoder
+    private let cache: any APICache
+    private let requestCoalescer = RequestCoalescer()
 
     /// The personal access token used for `Authorization: Bearer` headers.
     /// Loaded from Keychain on init; can be refreshed via ``reloadToken()``.
@@ -32,12 +35,19 @@ final class SRHTClient: Sendable {
         tokenLock.withLock { $0 != nil }
     }
 
-    init(session: URLSession = .shared, token: String? = nil) {
+    init(
+        session: URLSession = .shared,
+        token: String? = nil,
+        cache: (any APICache)? = nil
+    ) {
         self.session = session
         self.decoder = JSONDecoder()
         self.decoder.dateDecodingStrategy = .srhtFlexible
         self.encoder = JSONEncoder()
         self.tokenLock = OSAllocatedUnfairLock(initialState: token)
+        self.cache = cache ?? PersistentAPICache(
+            configuration: .accountScoped(accountID: token.map { Self.tokenCacheScope($0) } ?? "anonymous")
+        )
     }
 
     /// Update the stored token (e.g. after the user saves a new one in Keychain).
@@ -156,6 +166,130 @@ final class SRHTClient: Sendable {
         return result
     }
 
+    func executeCached<T: Decodable>(
+        service: SRHTService,
+        query: String,
+        variables: [String: any Sendable]? = nil,
+        responseType _: T.Type,
+        cacheKey: String,
+        resourceType: CacheResourceType,
+        ttl: TimeInterval,
+        policy: CachePolicy = .cacheFirstThenRefresh
+    ) async throws -> CachedValue<T> {
+        switch policy {
+        case .networkOnly:
+            let data = try await performGraphQLRequest(
+                service: service,
+                query: query,
+                variables: variables
+            )
+            let value: T = try decodeGraphQLData(data, service: service, query: query, variables: variables)
+            return CachedValue(value: value, metadata: nil, source: .network)
+
+        case .cacheOnly:
+            let entry = try await cache.read(cacheKey: cacheKey)
+            let value: T = try decodeGraphQLData(entry.payload, service: service, query: query, variables: variables)
+            return CachedValue(value: value, metadata: entry.metadata, source: .cache)
+
+        case .cacheFirstThenRefresh:
+            if let entry = try? await cache.read(cacheKey: cacheKey) {
+                let value: T = try decodeGraphQLData(entry.payload, service: service, query: query, variables: variables)
+                if entry.metadata.isExpired() {
+                    Task.detached { [self] in
+                        _ = try? await self.fetchAndCacheGraphQLData(
+                            service: service,
+                            query: query,
+                            variables: variables,
+                            cacheKey: cacheKey,
+                            resourceType: resourceType,
+                            ttl: ttl
+                        )
+                    }
+                }
+                return CachedValue(value: value, metadata: entry.metadata, source: .cache)
+            }
+
+            let (value, metadata): (T, CacheEntryMetadata?) = try await fetchAndCacheGraphQL(
+                service: service,
+                query: query,
+                variables: variables,
+                cacheKey: cacheKey,
+                resourceType: resourceType,
+                ttl: ttl
+            )
+            return CachedValue(value: value, metadata: metadata, source: .network)
+
+        case .refreshIgnoringCache:
+            let (value, metadata): (T, CacheEntryMetadata?) = try await fetchAndCacheGraphQL(
+                service: service,
+                query: query,
+                variables: variables,
+                cacheKey: cacheKey,
+                resourceType: resourceType,
+                ttl: ttl
+            )
+            return CachedValue(value: value, metadata: metadata, source: .network)
+        }
+    }
+
+    func fetchCachedText(
+        url: URL,
+        cacheKey: String,
+        resourceType: CacheResourceType = .buildLog,
+        ttl: TimeInterval,
+        policy: CachePolicy = .cacheFirstThenRefresh
+    ) async throws -> CachedValue<String> {
+        switch policy {
+        case .networkOnly:
+            let text = try await fetchText(url: url)
+            return CachedValue(value: text, metadata: nil, source: .network)
+        case .cacheOnly:
+            let entry = try await cache.read(cacheKey: cacheKey)
+            guard let text = String(data: entry.payload, encoding: .utf8) else {
+                throw SRHTError.decodingError(
+                    DecodingError.dataCorrupted(.init(codingPath: [], debugDescription: "Cached text is not UTF-8"))
+                )
+            }
+            return CachedValue(value: text, metadata: entry.metadata, source: .cache)
+        case .cacheFirstThenRefresh:
+            if let entry = try? await cache.read(cacheKey: cacheKey),
+               let text = String(data: entry.payload, encoding: .utf8) {
+                if entry.metadata.isExpired() {
+                    Task.detached { [self] in
+                        _ = try? await self.fetchAndCacheText(url: url, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+                    }
+                }
+                return CachedValue(value: text, metadata: entry.metadata, source: .cache)
+            }
+            let (text, metadata) = try await fetchAndCacheText(url: url, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+            return CachedValue(value: text, metadata: metadata, source: .network)
+        case .refreshIgnoringCache:
+            let (text, metadata) = try await fetchAndCacheText(url: url, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+            return CachedValue(value: text, metadata: metadata, source: .network)
+        }
+    }
+
+    func cachedPayload(forKey cacheKey: String) async -> Data? {
+        if let entry = try? await cache.read(cacheKey: cacheKey) {
+            return entry.payload
+        }
+        return responseCache.get(forKey: cacheKey)
+    }
+
+    func invalidateCache(prefix: String) async {
+        await cache.removeByPrefix(prefix)
+    }
+
+    func removeCachedValue(forKey cacheKey: String) async {
+        await cache.remove(cacheKey: cacheKey)
+        responseCache.remove(forKey: cacheKey)
+    }
+
+    func clearPersistentCache() async {
+        await cache.clearAll()
+        responseCache.clear()
+    }
+
     // MARK: - Multipart Upload
 
     /// Execute a GraphQL mutation with a file upload using the
@@ -614,6 +748,152 @@ final class SRHTClient: Sendable {
 // MARK: - Data Helper
 
 private extension SRHTClient {
+    func performGraphQLRequest(
+        service: SRHTService,
+        query: String,
+        variables: [String: any Sendable]?
+    ) async throws -> Data {
+        guard let token = tokenLock.withLock({ $0 }), !token.isEmpty else {
+            throw SRHTError.unauthorized
+        }
+
+        var request = URLRequest(url: service.url)
+        request.httpMethod = "POST"
+        request.setValue(Bundle.main.hutchUserAgent, forHTTPHeaderField: "User-Agent")
+        request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
+        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
+
+        let body = GraphQLRequestBody(
+            query: query,
+            variables: variables?.mapValues { AnyCodable($0) }
+        )
+        request.httpBody = try encoder.encode(body)
+
+        let (data, response): (Data, URLResponse)
+        do {
+            (data, response) = try await session.data(for: request)
+        } catch {
+            throw SRHTError.networkError(error)
+        }
+
+        if let http = response as? HTTPURLResponse {
+            if http.statusCode == 401 {
+                throw SRHTError.unauthorized
+            }
+            if !(200...299).contains(http.statusCode) {
+                try throwGraphQLErrorsIfPresent(in: data)
+                throw SRHTError.httpError(http.statusCode)
+            }
+        }
+
+        try throwGraphQLErrorsIfPresent(in: data)
+        return data
+    }
+
+    func decodeGraphQLData<T: Decodable>(
+        _ data: Data,
+        service: SRHTService,
+        query: String,
+        variables: [String: any Sendable]?
+    ) throws -> T {
+        let graphQLResponse: GraphQLResponse<T>
+        do {
+            graphQLResponse = try decoder.decode(GraphQLResponse<T>.self, from: data)
+        } catch {
+            #if DEBUG
+            let responseBody = String(data: data, encoding: .utf8) ?? "<non-utf8 response>"
+            logger.error(
+                """
+                Decoding failed for \(String(describing: T.self), privacy: .public)
+                service: \(service.rawValue, privacy: .public)
+                query:
+                \(query, privacy: .public)
+                variables:
+                \(String(describing: variables), privacy: .public)
+                error:
+                \(String(describing: error), privacy: .public)
+                response:
+                \(responseBody, privacy: .public)
+                """
+            )
+            #endif
+            throw SRHTError.decodingError(error)
+        }
+
+        if let errors = graphQLResponse.errors, !errors.isEmpty {
+            throw SRHTError.graphQLErrors(errors)
+        }
+
+        guard let result = graphQLResponse.data else {
+            throw SRHTError.decodingError(
+                DecodingError.dataCorrupted(.init(codingPath: [], debugDescription: "No data in response"))
+            )
+        }
+        return result
+    }
+
+    func fetchAndCacheGraphQL<T: Decodable>(
+        service: SRHTService,
+        query: String,
+        variables: [String: any Sendable]?,
+        cacheKey: String,
+        resourceType: CacheResourceType,
+        ttl: TimeInterval
+    ) async throws -> (T, CacheEntryMetadata?) {
+        let data = try await requestCoalescer.value(for: cacheKey) {
+            try await self.performGraphQLRequest(service: service, query: query, variables: variables)
+        }
+        let value: T = try decodeGraphQLData(data, service: service, query: query, variables: variables)
+        responseCache.set(data, forKey: cacheKey)
+        let metadata = try? await cache.write(payload: data, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+        return (value, metadata)
+    }
+
+    func fetchAndCacheGraphQLData(
+        service: SRHTService,
+        query: String,
+        variables: [String: any Sendable]?,
+        cacheKey: String,
+        resourceType: CacheResourceType,
+        ttl: TimeInterval
+    ) async throws -> CacheEntryMetadata? {
+        let data = try await requestCoalescer.value(for: cacheKey) {
+            try await self.performGraphQLRequest(service: service, query: query, variables: variables)
+        }
+        responseCache.set(data, forKey: cacheKey)
+        return try? await cache.write(payload: data, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+    }
+
+    func fetchAndCacheText(
+        url: URL,
+        cacheKey: String,
+        resourceType: CacheResourceType,
+        ttl: TimeInterval
+    ) async throws -> (String, CacheEntryMetadata?) {
+        let data = try await requestCoalescer.value(for: cacheKey) {
+            let text = try await self.fetchText(url: url)
+            guard let data = text.data(using: .utf8) else {
+                throw SRHTError.decodingError(
+                    DecodingError.dataCorrupted(.init(codingPath: [], debugDescription: "Text could not be encoded as UTF-8"))
+                )
+            }
+            return data
+        }
+        guard let text = String(data: data, encoding: .utf8) else {
+            throw SRHTError.decodingError(
+                DecodingError.dataCorrupted(.init(codingPath: [], debugDescription: "Response is not UTF-8 text"))
+            )
+        }
+        responseCache.set(data, forKey: cacheKey)
+        let metadata = try? await cache.write(payload: data, cacheKey: cacheKey, resourceType: resourceType, ttl: ttl)
+        return (text, metadata)
+    }
+
+    static func tokenCacheScope(_ token: String) -> String {
+        let digest = SHA256.hash(data: Data(token.utf8))
+        return digest.prefix(8).map { String(format: "%02x", $0) }.joined()
+    }
+
     func throwGraphQLErrorsIfPresent(in data: Data) throws {
         if let envelope = try? decoder.decode(GraphQLResponse<EmptyData>.self, from: data),
            let errors = envelope.errors,
@@ -632,6 +912,23 @@ private extension SRHTClient {
     }
 }
 
+private actor RequestCoalescer {
+    private var tasks: [String: Task<Data, Error>] = [:]
+
+    func value(for key: String, operation: @Sendable @escaping () async throws -> Data) async throws -> Data {
+        if let task = tasks[key] {
+            return try await task.value
+        }
+
+        let task = Task {
+            try await operation()
+        }
+        tasks[key] = task
+        defer { tasks.removeValue(forKey: key) }
+        return try await task.value
+    }
+}
+
 private extension Data {
     mutating func append(_ string: String) {
         if let data = string.data(using: .utf8) {
diff --git a/Hutch/Views/Builds/BuildDetailView.swift b/Hutch/Views/Builds/BuildDetailView.swift
index 334dff7..51d0c88 100644
--- a/Hutch/Views/Builds/BuildDetailView.swift
+++ b/Hutch/Views/Builds/BuildDetailView.swift
@@ -166,6 +166,12 @@ struct BuildDetailView: View {
             )
         } else if let job = viewModel.job {
             List {
+                if let cacheMetadata = viewModel.cacheMetadata {
+                    Section {
+                        StaleCacheStatusRow(metadata: cacheMetadata, isRefreshing: viewModel.isRefreshingCachedData)
+                    }
+                }
+
                 Section("Details") {
                     HStack {
                         Text("Status")
diff --git a/Hutch/Views/Builds/BuildDetailViewModel.swift b/Hutch/Views/Builds/BuildDetailViewModel.swift
index dcf70a0..74e8701 100644
--- a/Hutch/Views/Builds/BuildDetailViewModel.swift
+++ b/Hutch/Views/Builds/BuildDetailViewModel.swift
@@ -28,7 +28,7 @@ private struct SubmittedJob: Decodable, Sendable {
 @MainActor
 final class BuildDetailViewModel {
     private static let autoRefreshInterval: Duration = .seconds(5)
-    private static func cacheKey(for jobId: Int) -> String { "build.detail.\(jobId)" }
+    private static func cacheKey(for jobId: Int) -> String { APICacheKeys.buildDetail(jobId: jobId) }
 
     let jobId: Int
     private let client: SRHTClient
@@ -46,6 +46,8 @@ final class BuildDetailViewModel {
     private(set) var isRebuilding = false
     private(set) var isSubmittingEditedBuild = false
     private(set) var rawJobResponse: String?
+    private(set) var cacheMetadata: CacheEntryMetadata?
+    private(set) var isRefreshingCachedData = false
     var error: String?
     /// Transient error shown for action failures (cancel, rebuild, submit).
     /// Separate from `error` so auto-refresh doesn't immediately clear it.
@@ -128,22 +130,21 @@ final class BuildDetailViewModel {
         rawJobResponse = nil
 
         do {
-            let result = try await client.execute(
+            let result = try await client.executeCached(
                 service: .builds,
                 query: Self.detailQuery,
                 variables: ["id": jobId],
-                responseType: JobDetailResponse.self
+                responseType: JobDetailResponse.self,
+                cacheKey: Self.cacheKey(for: jobId),
+                resourceType: .buildDetail,
+                ttl: job?.status.isTerminal == true ? APICacheTTLs.completedBuildDetail : APICacheTTLs.activeBuild,
+                policy: .cacheFirstThenRefresh
             )
-            var loadedJob = result.job
-            loadedJob.tasks = loadedJob.tasks.enumerated().map { index, task in
-                task.withOrdinal(index)
-            }
-            if job != loadedJob {
-                job = loadedJob
-            }
-
-            if loadedJob.status.isTerminal {
-                stopAutoRefresh()
+            apply(result.value, metadata: result.metadata)
+            if result.isFromCache {
+                isLoading = false
+                await refreshJobInBackground()
+                return
             }
         } catch {
             self.error = error.userFacingMessage
@@ -159,26 +160,19 @@ final class BuildDetailViewModel {
 
         do {
             let cacheKey = Self.cacheKey(for: jobId)
-            let result = try await client.executeAndCache(
+            let result = try await client.executeCached(
                 service: .builds,
                 query: Self.detailQuery,
                 variables: ["id": jobId],
                 responseType: JobDetailResponse.self,
-                cacheKey: cacheKey
+                cacheKey: cacheKey,
+                resourceType: .buildDetail,
+                ttl: job?.status.isTerminal == true ? APICacheTTLs.completedBuildDetail : APICacheTTLs.activeBuild,
+                policy: .refreshIgnoringCache
             )
-            rawJobResponse = client.responseCache.get(forKey: cacheKey)
+            rawJobResponse = await client.cachedPayload(forKey: cacheKey)
                 .flatMap { String(data: $0, encoding: .utf8) }
-            var loadedJob = result.job
-            loadedJob.tasks = loadedJob.tasks.enumerated().map { index, task in
-                task.withOrdinal(index)
-            }
-            if job != loadedJob {
-                job = loadedJob
-            }
-
-            if loadedJob.status.isTerminal {
-                stopAutoRefresh()
-            }
+            apply(result.value, metadata: result.metadata)
         } catch {
             self.error = error.userFacingMessage
         }
@@ -201,7 +195,14 @@ final class BuildDetailViewModel {
         loadingTaskLogs.insert(cacheKey)
 
         do {
-            taskLogs[cacheKey] = try await client.fetchText(url: logURL)
+            let logCacheKey = APICacheKeys.buildLog(url: logURL, jobId: jobId, task: cacheKey)
+            let result = try await client.fetchCachedText(
+                url: logURL,
+                cacheKey: logCacheKey,
+                ttl: APICacheTTLs.completedBuildLog,
+                policy: .cacheFirstThenRefresh
+            )
+            taskLogs[cacheKey] = result.value
             failedTaskLogs.remove(cacheKey)
         } catch {
             failedTaskLogs.insert(cacheKey)
@@ -222,7 +223,13 @@ final class BuildDetailViewModel {
         isLoadingBuildLog = true
 
         do {
-            buildLogText = try await client.fetchText(url: logURL)
+            let result = try await client.fetchCachedText(
+                url: logURL,
+                cacheKey: APICacheKeys.buildLog(url: logURL, jobId: jobId),
+                ttl: jobIsTerminal ? APICacheTTLs.completedBuildLog : APICacheTTLs.activeBuild,
+                policy: jobIsTerminal ? .cacheFirstThenRefresh : .refreshIgnoringCache
+            )
+            buildLogText = result.value
         } catch {
             self.error = error.userFacingMessage
         }
@@ -287,6 +294,7 @@ final class BuildDetailViewModel {
                 variables: ["id": jobId],
                 responseType: CancelResponse.self
             )
+            await invalidateAfterMutation()
             await reloadJobPreservingDebugState()
         } catch {
             // Revert optimistic update on failure.
@@ -329,6 +337,7 @@ final class BuildDetailViewModel {
                 variables: variables,
                 responseType: SubmitJobResponse.self
             )
+            await invalidateAfterMutation()
             return result.submit.id
         } catch {
             setActionError("Couldn't rebuild. \(error.userFacingMessage)")
@@ -377,6 +386,7 @@ final class BuildDetailViewModel {
                 variables: variables,
                 responseType: SubmitJobResponse.self
             )
+            await invalidateAfterMutation()
             return result.submit.id
         } catch {
             setActionError("Couldn’t submit the build. \(error.userFacingMessage)")
@@ -417,6 +427,52 @@ final class BuildDetailViewModel {
         }
     }
 
+    private func refreshJobInBackground() async {
+        guard !isRefreshingCachedData else { return }
+        isRefreshingCachedData = true
+        defer { isRefreshingCachedData = false }
+
+        do {
+            let result = try await client.executeCached(
+                service: .builds,
+                query: Self.detailQuery,
+                variables: ["id": jobId],
+                responseType: JobDetailResponse.self,
+                cacheKey: Self.cacheKey(for: jobId),
+                resourceType: .buildDetail,
+                ttl: job?.status.isTerminal == true ? APICacheTTLs.completedBuildDetail : APICacheTTLs.activeBuild,
+                policy: .refreshIgnoringCache
+            )
+            apply(result.value, metadata: result.metadata)
+        } catch {
+            if job == nil {
+                self.error = error.userFacingMessage
+            }
+        }
+    }
+
+    private func apply(_ response: JobDetailResponse, metadata: CacheEntryMetadata?) {
+        cacheMetadata = metadata
+        var loadedJob = response.job
+        loadedJob.tasks = loadedJob.tasks.enumerated().map { index, task in
+            task.withOrdinal(index)
+        }
+        if job != loadedJob {
+            job = loadedJob
+        }
+
+        if loadedJob.status.isTerminal {
+            stopAutoRefresh()
+        }
+    }
+
+    private func invalidateAfterMutation() async {
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.builds.rawValue, "job"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.builds.rawValue, "jobs"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.builds.rawValue, "log"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix("home"))
+    }
+
     private var shouldAutoRefresh: Bool {
         guard let job else { return true }
         return !job.status.isTerminal
diff --git a/Hutch/Views/Repositories/FileTreeViewModel.swift b/Hutch/Views/Repositories/FileTreeViewModel.swift
index 9ccd74b..11f9e7f 100644
--- a/Hutch/Views/Repositories/FileTreeViewModel.swift
+++ b/Hutch/Views/Repositories/FileTreeViewModel.swift
@@ -90,6 +90,7 @@ final class FileTreeViewModel {
     private(set) var viewingObject: GitObject?
 
     private(set) var isLoading = false
+    private(set) var cacheMetadata: CacheEntryMetadata?
     var error: String?
 
     // Available references for the branch/tag picker
@@ -285,12 +286,18 @@ final class FileTreeViewModel {
         do {
             let result: RevparseResponse
             do {
-                result = try await client.execute(
+                let cached = try await client.executeCached(
                     service: service,
                     query: Self.rootTreeQuery,
                     variables: variables,
-                    responseType: RevparseResponse.self
+                    responseType: RevparseResponse.self,
+                    cacheKey: APICacheKeys.treeRoot(service: service, rid: repositoryRid, ref: revspec),
+                    resourceType: .repositoryTree,
+                    ttl: APICacheTTLs.movingRefFileContent,
+                    policy: .cacheFirstThenRefresh
                 )
+                result = cached.value
+                cacheMetadata = cached.metadata
             } catch {
                 if isMissingGitReferenceError(error) {
                     navStack = [FileNavEntry(name: "root", treeId: "")]
@@ -375,12 +382,18 @@ final class FileTreeViewModel {
         ]
 
         do {
-            let result = try await client.execute(
+            let cached = try await client.executeCached(
                 service: service,
                 query: Self.subtreeQuery,
                 variables: variables,
-                responseType: SubtreeResponse.self
+                responseType: SubtreeResponse.self,
+                cacheKey: APICacheKeys.treeEntries(service: service, rid: repositoryRid, treeId: treeId),
+                resourceType: .repositoryTree,
+                ttl: APICacheTTLs.immutableFileContent,
+                policy: .cacheFirstThenRefresh
             )
+            let result = cached.value
+            cacheMetadata = cached.metadata
             navStack.append(FileNavEntry(name: name, treeId: treeId))
             var allEntries = result.repository?.object?.entries?.results ?? []
             var cursor = result.repository?.object?.entries?.cursor
@@ -407,12 +420,18 @@ final class FileTreeViewModel {
         ]
 
         do {
-            let result = try await client.execute(
+            let cached = try await client.executeCached(
                 service: service,
                 query: Self.blobQuery,
                 variables: variables,
-                responseType: BlobResponse.self
+                responseType: BlobResponse.self,
+                cacheKey: APICacheKeys.blob(service: service, rid: repositoryRid, blobId: blobId),
+                resourceType: .repositoryFile,
+                ttl: APICacheTTLs.immutableFileContent,
+                policy: .cacheFirstThenRefresh
             )
+            let result = cached.value
+            cacheMetadata = cached.metadata
             viewingEntry = entry
             viewingObject = result.repository?.object ?? .unknown
         } catch {
@@ -453,12 +472,18 @@ final class FileTreeViewModel {
             ]
 
             do {
-                let result = try await client.execute(
+                let cached = try await client.executeCached(
                     service: service,
                     query: Self.subtreeQuery,
                     variables: variables,
-                    responseType: SubtreeResponse.self
+                    responseType: SubtreeResponse.self,
+                    cacheKey: APICacheKeys.treeEntries(service: service, rid: repositoryRid, treeId: targetEntry.treeId),
+                    resourceType: .repositoryTree,
+                    ttl: APICacheTTLs.immutableFileContent,
+                    policy: .cacheFirstThenRefresh
                 )
+                let result = cached.value
+                cacheMetadata = cached.metadata
                 var allEntries = result.repository?.object?.entries?.results ?? []
                 var cursor = result.repository?.object?.entries?.cursor
                 while let nextCursor = cursor {
@@ -480,13 +505,17 @@ final class FileTreeViewModel {
             "treeId": treeId,
             "cursor": cursor
         ]
-        let result = try await client.execute(
+        let cached = try await client.executeCached(
             service: service,
             query: Self.treeEntriesPageQuery,
             variables: variables,
-            responseType: SubtreeResponse.self
+            responseType: SubtreeResponse.self,
+            cacheKey: APICacheKeys.treeEntries(service: service, rid: repositoryRid, treeId: treeId, cursor: cursor),
+            resourceType: .repositoryTree,
+            ttl: APICacheTTLs.immutableFileContent,
+            policy: .cacheFirstThenRefresh
         )
-        return result.repository?.object?.entries ?? GitTreeEntryPage(results: [], cursor: nil)
+        return cached.value.repository?.object?.entries ?? GitTreeEntryPage(results: [], cursor: nil)
     }
 
     // MARK: - Linked File (used by README link interception)
@@ -517,13 +546,17 @@ final class FileTreeViewModel {
             "revspec": revspec,
             "path": path
         ]
-        let result = try await client.execute(
+        let cached = try await client.executeCached(
             service: service,
             query: Self.linkedFileQuery,
             variables: variables,
-            responseType: LinkedFileResponse.self
+            responseType: LinkedFileResponse.self,
+            cacheKey: APICacheKeys.path(service: service, rid: repositoryRid, ref: revspec, path: path),
+            resourceType: .repositoryFile,
+            ttl: revspec == "HEAD" ? APICacheTTLs.movingRefFileContent : APICacheTTLs.immutableFileContent,
+            policy: .cacheFirstThenRefresh
         )
-        return result.repository?.path
+        return cached.value.repository?.path
     }
 
     /// Dismiss the file view and go back to the directory listing.
diff --git a/Hutch/Views/Repositories/RepositoryDetailViewModel.swift b/Hutch/Views/Repositories/RepositoryDetailViewModel.swift
index 9aff1a4..4839437 100644
--- a/Hutch/Views/Repositories/RepositoryDetailViewModel.swift
+++ b/Hutch/Views/Repositories/RepositoryDetailViewModel.swift
@@ -138,6 +138,7 @@ final class RepositoryDetailViewModel {
     private(set) var readmePath: String?
     private(set) var isLoadingReadme = false
     private(set) var readmeLoaded = false
+    private(set) var readmeCacheMetadata: CacheEntryMetadata?
 
     // MARK: - Artifacts state
 
@@ -379,13 +380,18 @@ final class RepositoryDetailViewModel {
 
         do {
             // Step 1: Check the custom HTML readme set via the web UI
-            let result = try await client.execute(
+            let result = try await client.executeCached(
                 service: service,
                 query: Self.readmeQuery,
                 variables: ["rid": repository.rid],
-                responseType: ReadmeResponse.self
+                responseType: ReadmeResponse.self,
+                cacheKey: APICacheKeys.readme(service: service, rid: repository.rid),
+                resourceType: .repositoryReadme,
+                ttl: APICacheTTLs.movingRefFileContent,
+                policy: .cacheFirstThenRefresh
             )
-            if let html = result.repository?.readme, !html.isEmpty {
+            readmeCacheMetadata = result.metadata
+            if let html = result.value.repository?.readme, !html.isEmpty {
                 readmePath = nil
                 readmeContent = .html(html)
                 readmeLoaded = true
@@ -396,12 +402,18 @@ final class RepositoryDetailViewModel {
             for filename in Self.readmeFilenames {
                 let pathResult: PathResponse
                 do {
-                    pathResult = try await client.execute(
+                    let cached = try await client.executeCached(
                         service: service,
                         query: Self.readmeFileQuery(filename: filename),
                         variables: ["rid": repository.rid],
-                        responseType: PathResponse.self
+                        responseType: PathResponse.self,
+                        cacheKey: APICacheKeys.readme(service: service, rid: repository.rid, path: filename),
+                        resourceType: .repositoryReadme,
+                        ttl: APICacheTTLs.movingRefFileContent,
+                        policy: .cacheFirstThenRefresh
                     )
+                    pathResult = cached.value
+                    readmeCacheMetadata = cached.metadata
                 } catch {
                     if isEmptyRepositoryError(error) {
                         readmeContent = nil
diff --git a/Hutch/Views/Settings/SettingsView.swift b/Hutch/Views/Settings/SettingsView.swift
index ce980e2..f307429 100644
--- a/Hutch/Views/Settings/SettingsView.swift
+++ b/Hutch/Views/Settings/SettingsView.swift
@@ -133,6 +133,13 @@ struct SettingsView: View {
             .alignmentGuide(.listRowSeparatorLeading) { _ in 0 }
             .themedRow()
 
+            Button {
+                Task { await appState.client.clearPersistentCache() }
+            } label: {
+                Label("Clear Cache", systemImage: "externaldrive.badge.xmark")
+            }
+            .themedRow()
+
             Button("Reset App Data", role: .destructive) {
                 pendingDestructiveAction = .resetAppData
             }
diff --git a/Hutch/Views/Shared/StaleCacheStatusRow.swift b/Hutch/Views/Shared/StaleCacheStatusRow.swift
new file mode 100644
index 0000000..166fec4
--- /dev/null
+++ b/Hutch/Views/Shared/StaleCacheStatusRow.swift
@@ -0,0 +1,32 @@
+import SwiftUI
+
+struct StaleCacheStatusRow: View {
+    let metadata: CacheEntryMetadata
+    let isRefreshing: Bool
+
+    var body: some View {
+        HStack(spacing: 8) {
+            Image(systemName: metadata.isExpired() ? "clock.badge.exclamationmark" : "clock")
+                .foregroundStyle(.secondary)
+            Text(statusText)
+                .font(.caption)
+                .foregroundStyle(.secondary)
+            Spacer(minLength: 0)
+            if isRefreshing {
+                ProgressView()
+                    .controlSize(.mini)
+            }
+        }
+        .themedRow()
+    }
+
+    private var statusText: String {
+        if isRefreshing {
+            return "Showing cached data. Refreshing…"
+        }
+        if metadata.isExpired() {
+            return "Showing cached data. Last updated \(metadata.fetchedAt.relativeDescription)."
+        }
+        return "Last updated \(metadata.fetchedAt.relativeDescription)"
+    }
+}
diff --git a/Hutch/Views/Tickets/TicketDetailView.swift b/Hutch/Views/Tickets/TicketDetailView.swift
index 0028083..92263f6 100644
--- a/Hutch/Views/Tickets/TicketDetailView.swift
+++ b/Hutch/Views/Tickets/TicketDetailView.swift
@@ -169,6 +169,12 @@ struct TicketDetailView: View {
         } else if let ticket = viewModel.ticket {
             ScrollView {
                 VStack(alignment: .leading, spacing: 0) {
+                    if let cacheMetadata = viewModel.cacheMetadata {
+                        StaleCacheStatusRow(metadata: cacheMetadata, isRefreshing: viewModel.isRefreshingCachedData)
+                            .padding(.horizontal)
+                            .padding(.vertical, 8)
+                    }
+
                     // Header
                     ticketHeader(ticket, viewModel: viewModel)
 
diff --git a/Hutch/Views/Tickets/TicketDetailViewModel.swift b/Hutch/Views/Tickets/TicketDetailViewModel.swift
index 483f749..df2fd46 100644
--- a/Hutch/Views/Tickets/TicketDetailViewModel.swift
+++ b/Hutch/Views/Tickets/TicketDetailViewModel.swift
@@ -98,7 +98,7 @@ private struct LabelsPage: Decodable, Sendable {
 @MainActor
 final class TicketDetailViewModel {
     private static func cacheKey(ownerUsername: String, trackerRid: String, ticketId: Int) -> String {
-        "ticket.detail.\(ownerUsername).\(trackerRid).\(ticketId)"
+        APICacheKeys.ticketDetail(owner: ownerUsername, trackerRid: trackerRid, ticketId: ticketId)
     }
 
     let ownerUsername: String
@@ -114,6 +114,8 @@ final class TicketDetailViewModel {
     private(set) var isPerformingAction = false
     private(set) var trackerLabels: [TicketLabel] = []
     private(set) var rawTicketResponse: String?
+    private(set) var cacheMetadata: CacheEntryMetadata?
+    private(set) var isRefreshingCachedData = false
     var commentText = ""
     var error: String?
 
@@ -291,30 +293,25 @@ final class TicketDetailViewModel {
         rawTicketResponse = nil
 
         do {
-            let result = try await client.execute(
+            let result = try await client.executeCached(
                 service: .todo,
                 query: Self.detailQuery,
                 variables: [
                     "rid": trackerRid,
                     "ticketId": ticketId
                 ],
-                responseType: TicketDetailResponse.self
-            )
-            let payload = result.tracker.ticket
-            ticket = TicketDetail(
-                id: payload.id,
-                created: payload.created,
-                updated: payload.updated,
-                title: payload.title,
-                description: payload.description,
-                status: payload.status,
-                resolution: payload.resolution,
-                authenticity: payload.authenticity,
-                submitter: payload.submitter,
-                assignees: payload.assignees,
-                labels: payload.labels
+                responseType: TicketDetailResponse.self,
+                cacheKey: Self.cacheKey(ownerUsername: ownerUsername, trackerRid: trackerRid, ticketId: ticketId),
+                resourceType: .ticketDetail,
+                ttl: APICacheTTLs.ticketDetail,
+                policy: .cacheFirstThenRefresh
             )
-            events = payload.events.results.sorted(by: Self.timelineOrder)
+            apply(result.value, metadata: result.metadata)
+            if result.isFromCache {
+                isLoading = false
+                await refreshTicketInBackground()
+                return
+            }
         } catch {
             self.error = error.userFacingMessage
         }
@@ -329,7 +326,7 @@ final class TicketDetailViewModel {
 
         do {
             let cacheKey = Self.cacheKey(ownerUsername: ownerUsername, trackerRid: trackerRid, ticketId: ticketId)
-            let result = try await client.executeAndCache(
+            let result = try await client.executeCached(
                 service: .todo,
                 query: Self.detailQuery,
                 variables: [
@@ -337,25 +334,14 @@ final class TicketDetailViewModel {
                     "ticketId": ticketId
                 ],
                 responseType: TicketDetailResponse.self,
-                cacheKey: cacheKey
+                cacheKey: cacheKey,
+                resourceType: .ticketDetail,
+                ttl: APICacheTTLs.ticketDetail,
+                policy: .refreshIgnoringCache
             )
-            rawTicketResponse = client.responseCache.get(forKey: cacheKey)
+            rawTicketResponse = await client.cachedPayload(forKey: cacheKey)
                 .flatMap { String(data: $0, encoding: .utf8) }
-            let payload = result.tracker.ticket
-            ticket = TicketDetail(
-                id: payload.id,
-                created: payload.created,
-                updated: payload.updated,
-                title: payload.title,
-                description: payload.description,
-                status: payload.status,
-                resolution: payload.resolution,
-                authenticity: payload.authenticity,
-                submitter: payload.submitter,
-                assignees: payload.assignees,
-                labels: payload.labels
-            )
-            events = payload.events.results.sorted(by: Self.timelineOrder)
+            apply(result.value, metadata: result.metadata)
         } catch {
             self.error = error.userFacingMessage
         }
@@ -391,6 +377,7 @@ final class TicketDetailViewModel {
             events.append(event)
             events.sort(by: Self.timelineOrder)
             commentText = ""
+            await invalidateAfterMutation()
         } catch {
             self.error = error.userFacingMessage
         }
@@ -423,6 +410,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: UpdateStatusResponse.self
             )
+            await invalidateAfterMutation()
             // Re-fetch the ticket to get updated status/resolution
             await reloadTicketPreservingDebugState()
         } catch {
@@ -457,6 +445,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: AssignUserResponse.self
             )
+            await invalidateAfterMutation()
             // Reload to reflect the change
             await reloadTicketPreservingDebugState()
         } catch {
@@ -503,6 +492,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: AssignUserResponse.self
             )
+            await invalidateAfterMutation()
             await reloadTicketPreservingDebugState()
         } catch {
             ticket = TicketDetail(
@@ -550,6 +540,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: UnassignUserResponse.self
             )
+            await invalidateAfterMutation()
             // Reload to reflect the change
             await reloadTicketPreservingDebugState()
         } catch {
@@ -575,6 +566,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: LabelTicketResponse.self
             )
+            await invalidateAfterMutation()
             await reloadTicketPreservingDebugState()
         } catch {
             self.error = error.userFacingMessage
@@ -599,6 +591,7 @@ final class TicketDetailViewModel {
                 ],
                 responseType: UnlabelTicketResponse.self
             )
+            await invalidateAfterMutation()
             await reloadTicketPreservingDebugState()
         } catch {
             self.error = error.userFacingMessage
@@ -654,6 +647,61 @@ final class TicketDetailViewModel {
         }
     }
 
+    private func refreshTicketInBackground() async {
+        guard !isRefreshingCachedData else { return }
+        isRefreshingCachedData = true
+        defer { isRefreshingCachedData = false }
+
+        do {
+            let result = try await client.executeCached(
+                service: .todo,
+                query: Self.detailQuery,
+                variables: [
+                    "rid": trackerRid,
+                    "ticketId": ticketId
+                ],
+                responseType: TicketDetailResponse.self,
+                cacheKey: Self.cacheKey(ownerUsername: ownerUsername, trackerRid: trackerRid, ticketId: ticketId),
+                resourceType: .ticketDetail,
+                ttl: APICacheTTLs.ticketDetail,
+                policy: .refreshIgnoringCache
+            )
+            apply(result.value, metadata: result.metadata)
+        } catch {
+            if ticket == nil {
+                self.error = error.userFacingMessage
+            }
+        }
+    }
+
+    private func apply(_ response: TicketDetailResponse, metadata: CacheEntryMetadata?) {
+        cacheMetadata = metadata
+        let payload = response.tracker.ticket
+        let updatedTicket = TicketDetail(
+            id: payload.id,
+            created: payload.created,
+            updated: payload.updated,
+            title: payload.title,
+            description: payload.description,
+            status: payload.status,
+            resolution: payload.resolution,
+            authenticity: payload.authenticity,
+            submitter: payload.submitter,
+            assignees: payload.assignees,
+            labels: payload.labels
+        )
+        ticket = updatedTicket
+        let updatedEvents = payload.events.results.sorted(by: Self.timelineOrder)
+        events = updatedEvents
+    }
+
+    private func invalidateAfterMutation() async {
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.todo.rawValue, "ticket"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.todo.rawValue, "tickets"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix(SRHTService.todo.rawValue, "tracker"))
+        await client.invalidateCache(prefix: APICacheKeys.prefix("home"))
+    }
+
     static func matchesAssignee(_ entity: Entity, user: User) -> Bool {
         let assigneeCanonical = normalizedCanonicalName(entity.canonicalName)
         let userCanonical = normalizedCanonicalName(user.canonicalName)