fix(session): allow clearing archived timestamp via HTTP API

packages/opencode/src/server/routes/instance/httpapi/groups/session.ts

@@ -48,7 +48,7 @@ export const UpdatePayload = Schema.Struct({
   permission: Schema.optional(Permission.Ruleset),
   time: Schema.optional(
     Schema.Struct({
-      archived: Schema.optional(Session.ArchivedTimestamp),
+      archived: Schema.optional(Schema.NullOr(Session.ArchivedTimestamp)),
     }),
   ),
 })

packages/opencode/src/session/session.ts

@@ -262,7 +262,7 @@ export const RemoveInput = SessionID
 export const SetTitleInput = Schema.Struct({ sessionID: SessionID, title: Schema.String })
 export const SetArchivedInput = Schema.Struct({
   sessionID: SessionID,
-  time: Schema.optional(ArchivedTimestamp),
+  time: Schema.optional(Schema.NullOr(ArchivedTimestamp)),
 })
 export const SetPermissionInput = Schema.Struct({
   sessionID: SessionID,
@@ -462,7 +462,7 @@ export interface Interface {
   readonly touch: (sessionID: SessionID) => Effect.Effect<void>
   readonly get: (id: SessionID) => Effect.Effect<Info, NotFound>
   readonly setTitle: (input: { sessionID: SessionID; title: string }) => Effect.Effect<void>
-  readonly setArchived: (input: { sessionID: SessionID; time?: number }) => Effect.Effect<void>
+  readonly setArchived: (input: { sessionID: SessionID; time?: number | null }) => Effect.Effect<void>
   readonly setPermission: (input: { sessionID: SessionID; permission: Permission.Ruleset }) => Effect.Effect<void>
   readonly setRevert: (input: {
     sessionID: SessionID
@@ -728,8 +728,8 @@ export const layer: Layer.Layer<
       yield* patch(input.sessionID, { title: input.title })
     })
 
-    const setArchived = Effect.fn("Session.setArchived")(function* (input: { sessionID: SessionID; time?: number }) {
-      yield* patch(input.sessionID, { time: { archived: input.time } })
+    const setArchived = Effect.fn("Session.setArchived")(function* (input: { sessionID: SessionID; time?: number | null }) {
+      yield* patch(input.sessionID, { time: { archived: input.time ?? null } })
     })
 
     const setPermission = Effect.fn("Session.setPermission")(function* (input: {

packages/opencode/test/server/global-session-list.test.ts

@@ -69,6 +69,25 @@ describe("session.listGlobal", () => {
     { git: true },
   )
 
+  it.instance(
+    "includes sessions after unarchiving",
+    () =>
+      Effect.gen(function* () {
+        const session = yield* withSession({ title: "unarchive-me" })
+
+        yield* SessionNs.Service.use((svc) => svc.setArchived({ sessionID: session.id, time: Date.now() }))
+
+        const archived = yield* Effect.sync(() => [...SessionNs.listGlobal({ limit: 200 })])
+        expect(archived.map((s) => s.id)).not.toContain(session.id)
+
+        yield* SessionNs.Service.use((svc) => svc.setArchived({ sessionID: session.id }))
+
+        const active = yield* Effect.sync(() => [...SessionNs.listGlobal({ limit: 200 })])
+        expect(active.map((s) => s.id)).toContain(session.id)
+      }),
+    { git: true },
+  )
+
   it.instance(
     "supports cursor pagination",
     () =>

packages/opencode/test/server/httpapi-session.test.ts

@@ -697,6 +697,31 @@ describe("session HttpApi", () => {
     { git: true, config: { formatter: false, lsp: false } },
   )
 
+  it.instance(
+    "clears archived timestamp when null is passed",
+    () =>
+      Effect.gen(function* () {
+        const test = yield* TestInstance
+        const headers = { "x-opencode-directory": test.directory, "content-type": "application/json" }
+        const session = yield* createSession({ title: "to-unarchive" })
+
+        yield* request(pathFor(SessionPaths.update, { sessionID: session.id }), {
+          method: "PATCH",
+          headers,
+          body: JSON.stringify({ time: { archived: Date.now() } }),
+        })
+
+        const response = yield* request(pathFor(SessionPaths.update, { sessionID: session.id }), {
+          method: "PATCH",
+          headers,
+          body: JSON.stringify({ time: { archived: null } }),
+        })
+        expect(response.status).toBe(200)
+        expect((yield* json<Session.Info>(response)).time.archived).toBeUndefined()
+      }),
+    { git: true, config: { formatter: false, lsp: false } },
+  )
+
   it.instance(
     "uses project-scoped path and directory precedence",
     () =>