deepseek-ai/deepseek-harness · error · Error

rpcId mismatch for ${method}: sent ${message.rpcId}, got ${f

Error message

rpcId mismatch for ${method}: sent ${message.rpcId}, got ${full.rpcId}

What it means

Error "rpcId mismatch for ${method}: sent ${message.rpcId}, got ${full.rpcId}" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/host/apiproxy/src/fetch/client.ts:344

  }

  /**
   * Unary protocol path: mint → tap → POST full form → envelope parse → verify
   * echo → value parse → tap → narrow. Virtual so a fake carrier (fixture) can
   * override transport at this layer.
   */
  protected async callUnary<K extends keyof RpcMethodMap>(
    method: K,
    payload: RequestPayload<K>,
    signal?: AbortSignal,
    timeoutPolicy: UnaryTimeoutPolicy = 'default',
  ): Promise<RpcResponse<ResponseValue<K>>> {
    const message: ClientRequest = { type: 'client-request', rpcId: this.mintRpcId(), method, payload }
    this.onEnvelope(message)
    const response = await this.postJson(`/api/${method}`, message, signal, timeoutPolicy)
    const full = serverResponseSchema.parse(await response.json())
    this.onEnvelope(full)
    if (full.rpcId !== message.rpcId) throw new Error(`rpcId mismatch for ${method}: sent ${message.rpcId}, got ${full.rpcId}`)
    if (!full.result.ok) return { rpcId: full.rpcId, result: full.result }
    // Second-level S→C parse: the ok value must match the method's Value schema (mirror of the
    // handler's request-payload parse). The cast collapses the Wire<> widening, same as the handler side.
    const value = UNARY_VALUE_SCHEMAS[method].parse(full.result.value) as ResponseValue<K>
    return { rpcId: full.rpcId, result: { ok: true, value } }
  }

  /** Mux stream opener; virtual for the same override reason as callUnary. */
  protected openMux(_payload: Parameters<ApiProxy['events']['mux']>[0]['payload'], signal: AbortSignal, onOpen?: () => void): AsyncIterable<RpcRequest<MuxFrame>> {
    return this.readSse('/api/events.mux', signal, muxFrameSchema, onOpen)
  }

  /** Host stream opener; virtual. */
  protected openHost(_payload: Parameters<ApiProxy['events']['host']>[0]['payload'], signal: AbortSignal, onOpen?: () => void): AsyncIterable<RpcRequest<HostFrame>> {
    return this.readSse('/api/events.host', signal, hostFrameSchema, onOpen)
  }

  /**

View on GitHub (pinned to b150a551b8)

When it happens

Trigger: Thrown at packages/host/apiproxy/src/fetch/client.ts:344 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/677e78133e095885. Report an issue: GitHub.