feat(opencode): expand acp v1 support

packages/opencode/src/acp/agent.ts

@@ -5,6 +5,7 @@ import {
   type AuthenticateRequest,
   type CancelNotification,
   type CloseSessionRequest,
+  type DeleteSessionRequest,
   type ForkSessionRequest,
   type InitializeRequest,
   type ListSessionsRequest,
@@ -51,6 +52,10 @@ export class Agent implements ACPAgent {
     return run(this.service.listSessions(params))
   }
 
+  deleteSession(params: DeleteSessionRequest) {
+    return run(this.service.deleteSession(params))
+  }
+
   resumeSession(params: ResumeSessionRequest) {
     return run(this.service.resumeSession(params))
   }

packages/opencode/src/acp/event.ts

@@ -30,7 +30,12 @@ type GlobalEventStream = {
   stream: AsyncIterable<GlobalEventEnvelope>
 }
 
-export function start(input: { sdk: OpencodeClient; connection: Connection; session: ACPSession.Interface }) {
+export function start(input: {
+  sdk: OpencodeClient
+  connection: Connection
+  session: ACPSession.Interface
+  capabilities: ACPPermission.Capabilities
+}) {
   const subscription = new Subscription(input)
   subscription.start()
   return subscription
@@ -48,6 +53,7 @@ export class Subscription {
       sdk: OpencodeClient
       connection: Connection
       session: ACPSession.Interface
+      capabilities: ACPPermission.Capabilities
     },
   ) {
     this.permission = new ACPPermission.Handler(input)

packages/opencode/src/acp/permission.ts

@@ -16,6 +16,7 @@ import { Effect } from "effect"
 type PermissionEvent = Extract<Event, { type: "permission.asked" }>
 type Reply = "once" | "always" | "reject"
 type Connection = Partial<Pick<AgentSideConnection, "requestPermission" | "writeTextFile">>
+export type Capabilities = { writeTextFile: boolean }
 
 const permissionOptions: PermissionOption[] = [
   { optionId: "once", kind: "allow_once", name: "Allow once" },
@@ -31,6 +32,7 @@ export class Handler {
       sdk: OpencodeClient
       connection: Connection
       session: ACPSession.Interface
+      capabilities: Capabilities
     },
   ) {}
 
@@ -99,7 +101,7 @@ export class Handler {
   private async writeProposedEdit(sessionId: string, metadata: ToolInput) {
     const filepath = stringValue(metadata.filepath)
     const diff = stringValue(metadata.diff)
-    if (!filepath || !diff || !this.input.connection.writeTextFile) return
+    if (!filepath || !diff || !this.input.capabilities.writeTextFile || !this.input.connection.writeTextFile) return
 
     const content = (await exists(filepath)) ? await readText(filepath) : ""
     const next = applyPatch(content, diff)

packages/opencode/src/acp/service.ts

@@ -6,6 +6,8 @@ import {
   type CancelNotification,
   type CloseSessionRequest,
   type CloseSessionResponse,
+  type DeleteSessionRequest,
+  type DeleteSessionResponse,
   type ForkSessionRequest,
   type ForkSessionResponse,
   type InitializeRequest,
@@ -56,6 +58,7 @@ export type Interface = {
   readonly newSession: (input: NewSessionRequest) => Effect.Effect<NewSessionResponse, Error>
   readonly loadSession: (input: LoadSessionRequest) => Effect.Effect<LoadSessionResponse, Error>
   readonly listSessions: (input: ListSessionsRequest) => Effect.Effect<ListSessionsResponse, Error>
+  readonly deleteSession: (input: DeleteSessionRequest) => Effect.Effect<DeleteSessionResponse, Error>
   readonly resumeSession: (input: ResumeSessionRequest) => Effect.Effect<ResumeSessionResponse, Error>
   readonly closeSession: (input: CloseSessionRequest) => Effect.Effect<CloseSessionResponse, Error>
   readonly forkSession: (input: ForkSessionRequest) => Effect.Effect<ForkSessionResponse, Error>
@@ -81,13 +84,15 @@ export function make(input: {
   const directoryService = input.directory ?? makeDirectoryService(input.sdk)
   const registeredMcp = new Map<string, Set<string>>()
   const sessionSnapshots = new Map<string, Directory.Snapshot>()
+  const capabilities = { writeTextFile: false }
   const events = input.connection
-    ? ACPEvent.start({ sdk: input.sdk, connection: input.connection, session })
+    ? ACPEvent.start({ sdk: input.sdk, connection: input.connection, session, capabilities })
     : undefined
   if (events) input.eventSubscription?.(events)
 
   const initialize = Effect.fn("ACP.initialize")(function* (params: InitializeRequest) {
     const started = performance.now()
+    capabilities.writeTextFile = params.clientCapabilities?.fs?.writeTextFile === true
     const authMethod: AuthMethod = {
       description: "Run `opencode auth login` in the terminal",
       name: "Login with opencode",
@@ -118,6 +123,7 @@ export function make(input: {
         },
         sessionCapabilities: {
           close: {},
+          delete: {},
           fork: {},
           list: {},
           resume: {},
@@ -284,6 +290,25 @@ export function make(input: {
     }
   })
 
+  const deleteSession = Effect.fn("ACP.deleteSession")(function* (params: DeleteSessionRequest) {
+    const current = yield* session.tryGet(params.sessionId)
+    yield* request(
+      () =>
+        input.sdk.session.delete(
+          {
+            sessionID: params.sessionId,
+            ...(current ? { directory: current.cwd } : {}),
+          },
+          { throwOnError: true },
+        ),
+      "session",
+    )
+    yield* session.remove(params.sessionId)
+    registeredMcp.delete(params.sessionId)
+    sessionSnapshots.delete(params.sessionId)
+    return {}
+  })
+
   const resumeSession = Effect.fn("ACP.resumeSession")(function* (params: ResumeSessionRequest) {
     const snapshot = yield* directorySnapshot(params.cwd)
     yield* request(
@@ -465,6 +490,7 @@ export function make(input: {
     newSession,
     loadSession,
     listSessions,
+    deleteSession,
     resumeSession,
     closeSession,
     forkSession,

packages/opencode/test/acp/event.test.ts

@@ -108,7 +108,12 @@ function createHarness(messages: Record<string, SessionMessageResponse> = {}) {
     },
   } satisfies Pick<AgentSideConnection, "sessionUpdate">
   const session = makeSessionService()
-  const subscription = new ACPEvent.Subscription({ sdk, connection, session })
+  const subscription = new ACPEvent.Subscription({
+    sdk,
+    connection,
+    session,
+    capabilities: { writeTextFile: false },
+  })
 
   return { calls, connection, events, sdk, session, subscription, updates }
 }

packages/opencode/test/acp/permission.test.ts

@@ -46,10 +46,12 @@ function makeSessionService() {
 function createHarness(
   requestPermission: (params: RequestPermissionRequest) => Promise<RequestPermissionResponse> = () =>
     Promise.resolve({ outcome: { outcome: "selected", optionId: "once" } }),
+  writeTextFile = false,
 ) {
   const replies: PermissionReplyParams[] = []
   const requests: RequestPermissionRequest[] = []
   const updates: SessionUpdateParams[] = []
+  const writes: Parameters<AgentSideConnection["writeTextFile"]>[0][] = []
   const session = makeSessionService()
   const sdk = {
     permission: {
@@ -71,10 +73,19 @@ function createHarness(
       updates.push(params)
       return Promise.resolve()
     },
-  } satisfies Pick<AgentSideConnection, "requestPermission" | "sessionUpdate">
+    writeTextFile: (params: Parameters<AgentSideConnection["writeTextFile"]>[0]) => {
-  const subscription = new ACPEvent.Subscription({ sdk, connection, session })
+      writes.push(params)
+      return Promise.resolve({})
+    },
+  } satisfies Pick<AgentSideConnection, "requestPermission" | "sessionUpdate" | "writeTextFile">
+  const subscription = new ACPEvent.Subscription({
+    sdk,
+    connection,
+    session,
+    capabilities: { writeTextFile },
+  })
 
-  return { connection, replies, requests, sdk, session, subscription, updates }
+  return { connection, replies, requests, sdk, session, subscription, updates, writes }
 }
 
 async function createSession(session: ACPSession.Interface, sessionId: string, cwd = "/workspace") {
@@ -242,6 +253,27 @@ describe("acp permissions", () => {
     })
   })
 
+  it("syncs proposed edits only when the client advertised writeTextFile", async () => {
+    const filepath = await tempFile("sync.ts", "before\n")
+    const metadata = {
+      filepath,
+      diff: createTwoFilesPatch(filepath, filepath, "before\n", "after\n"),
+    }
+    const unsupported = createHarness(undefined, false)
+    const supported = createHarness(undefined, true)
+    await createSession(unsupported.session, "ses_unsupported")
+    await createSession(supported.session, "ses_supported")
+
+    unsupported.subscription.handle(
+      permissionAsked("ses_unsupported", "perm_unsupported", { permission: "edit", metadata }),
+    )
+    supported.subscription.handle(permissionAsked("ses_supported", "perm_supported", { permission: "edit", metadata }))
+    await pollUntil(() => unsupported.replies.length === 1 && supported.replies.length === 1, "edits were not replied")
+
+    expect(unsupported.writes).toEqual([])
+    expect(supported.writes).toEqual([{ sessionId: "ses_supported", path: filepath, content: "after\n" }])
+  })
+
   it("includes per-file diff blocks and locations for apply_patch permission metadata", async () => {
     const first = await tempFile("first.ts", "one\n")
     const second = await tempFile("second.ts", "alpha\n")

packages/opencode/test/acp/service-session.test.ts

@@ -152,6 +152,7 @@ describe("ACP service sessions", () => {
     const updates: SessionNotification[] = []
     const mcpAdds: string[] = []
     const aborts: string[] = []
+    const deletes: string[] = []
     const forks: string[] = []
     const prompts: unknown[] = []
     const commands: unknown[] = []
@@ -196,6 +197,10 @@ describe("ACP service sessions", () => {
             data: input.directory ? sessions.filter((session) => session.directory === input.directory) : sessions,
           }),
         messages: () => Promise.resolve({ data: messages }),
+        delete: (input: { sessionID: string }) => {
+          deletes.push(input.sessionID)
+          return Promise.resolve({ data: true })
+        },
         prompt:
           options?.prompt ??
           ((input: unknown) => {
@@ -268,6 +273,7 @@ describe("ACP service sessions", () => {
       updates,
       mcpAdds,
       aborts,
+      deletes,
       forks,
       prompts,
       commands,
@@ -382,6 +388,16 @@ describe("ACP service sessions", () => {
     expect(listed.sessions[0]?.cwd).toBe("/workspace")
   })
 
+  it("deletes sessions from backing and local storage", async () => {
+    const { service, deletes } = makeService()
+    const created = await Effect.runPromise(service.newSession({ cwd: "/workspace", mcpServers: [] }))
+
+    expect(await Effect.runPromise(service.deleteSession({ sessionId: created.sessionId }))).toEqual({})
+    expect(deletes).toEqual([created.sessionId])
+    const listed = await Effect.runPromise(service.listSessions({ cwd: "/workspace" }))
+    expect(listed.sessions.some((item) => item.sessionId === created.sessionId)).toBe(false)
+  })
+
   it("lists all sessions with next cursor when the first page is full", async () => {
     const { service } = makeService()
     const first = await Effect.runPromise(service.listSessions({}))

packages/opencode/test/cli/acp/initialize-auth.test.ts

@@ -18,6 +18,7 @@ describe("opencode acp initialize/auth subprocess", () => {
         expect(initialized.agentCapabilities?.mcpCapabilities?.sse).toBe(true)
         expect(initialized.agentCapabilities?.loadSession).toBe(true)
         expect(initialized.agentCapabilities?.sessionCapabilities?.close).toEqual({})
+        expect(initialized.agentCapabilities?.sessionCapabilities?.delete).toEqual({})
         expect(initialized.agentCapabilities?.sessionCapabilities?.fork).toEqual({})
         expect(initialized.agentCapabilities?.sessionCapabilities?.list).toEqual({})
         expect(initialized.agentCapabilities?.sessionCapabilities?.resume).toEqual({})

packages/opencode/test/cli/acp/lifecycle.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect } from "bun:test"
 import type {
   CloseSessionResponse,
+  DeleteSessionResponse,
   ListSessionsResponse,
   LoadSessionResponse,
   ResumeSessionResponse,
@@ -82,6 +83,25 @@ describe("opencode acp lifecycle subprocess", () => {
     60_000,
   )
 
+  cliIt.live(
+    "delete capability and delete request",
+    ({ home, llm, opencode }) =>
+      Effect.gen(function* () {
+        const acp = yield* createAcpClient(
+          { opencode },
+          { OPENCODE_CONFIG_CONTENT: JSON.stringify(verifierConfig(llm.url)) },
+        )
+        const initialized = yield* initialize(acp)
+        expect(initialized.agentCapabilities?.sessionCapabilities?.delete).toEqual({})
+        const session = yield* newSession(acp, home)
+
+        expectOk(yield* acp.request<DeleteSessionResponse>("session/delete", { sessionId: session.sessionId }))
+        const listed = expectOk(yield* acp.request<ListSessionsResponse>("session/list", { cwd: home }))
+        expect(listed.sessions.some((item) => item.sessionId === session.sessionId)).toBe(false)
+      }),
+    60_000,
+  )
+
   cliIt.live(
     "resume capability advertisement",
     ({ opencode }) =>