{"record":{"id":"6aca886bd358a3c3","repo":"vercel/ai","slug":"the-installed-acp-sdk-cannot-send-session-prompt-m","errorCode":null,"errorMessage":"The installed ACP SDK cannot send session prompt metadata while preserving streamed updates.","messagePattern":"The installed ACP SDK cannot send session prompt metadata while preserving streamed updates\\.","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/harness-acp/src/v1/bridge/index.ts","lineNumber":824,"sourceCode":"  agent: acp.ClientContext;\n  prompt: Array<acp.ContentBlock>;\n  meta: Record<string, unknown> | undefined;\n}): Promise<acp.PromptResponse> {\n  if (meta == null) return session.prompt(prompt);\n  if (session.promptWithMeta != null) {\n    return session.promptWithMeta({ prompt, meta });\n  }\n  const updates = (\n    session as unknown as {\n      updates?: {\n        clearErrors(): void;\n        enqueue(value: acp.ActiveSessionMessage): void;\n        reject(error: unknown): void;\n      };\n    }\n  ).updates;\n  if (updates == null) {\n    throw new Error(\n      'The installed ACP SDK cannot send session prompt metadata while preserving streamed updates.',\n    );\n  }\n  updates.clearErrors();\n  const response = agent.request<acp.PromptResponse, acp.PromptRequest>(\n    acp.methods.agent.session.prompt,\n    {\n      sessionId: session.sessionId,\n      prompt,\n      _meta: meta,\n    },\n  );\n  void response.then(\n    value => {\n      updates.enqueue({\n        kind: 'stop',\n        response: value,\n        stopReason: value.stopReason,","sourceCodeStart":806,"sourceCodeEnd":842,"githubUrl":"https://github.com/vercel/ai/blob/69428b1f8b037e4d118fb4853428d5c4e620493c/packages/harness-acp/src/v1/bridge/index.ts#L806-L842","documentation":"Error \"The installed ACP SDK cannot send session prompt metadata while preserving streamed updates.\" thrown in vercel/ai.","triggerScenarios":"Thrown at packages/harness-acp/src/v1/bridge/index.ts:824 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"69428b1f8b037e4d118fb4853428d5c4e620493c","analyzedAt":"2026-08-30T12:32:21.016Z","schemaVersion":2},"datasetVersion":"2026-08-30T13:17:10.514Z"}