deepseek-ai/deepseek-harness · error · TransportClosedError

DeepSeek Harness runtime client is closed

Error message

DeepSeek Harness runtime client is closed

What it means

Error "DeepSeek Harness runtime client is closed" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/sdk/client/src/client.ts:204

  private transport: JsonRpcLineTransport | undefined
  private readonly stderrTail: string[] = []
  private readonly subscriptions = new Map<string, NotificationSubscriptionImpl>()
  private readonly sessionParents = new Map<string, string>()
  private subscriptionSerial = 0
  private exitCode: number | null | undefined
  private spawnError: Error | undefined
  private streamsSettled: Promise<void> = Promise.resolve()
  private closeTask: Promise<void> | undefined

  /** @param options - launch spec, complete child environment, and timeouts. */
  constructor(readonly options: HarnessClientOptions) {}

  /**
   * Spawn the runtime subprocess and start reading frames. Idempotent while
   * the process is live; rejects reuse after {@link close}.
   */
  start(): void {
    if (this.closeTask !== undefined) throw new TransportClosedError('DeepSeek Harness runtime client is closed')
    if (this.child !== undefined) return
    const child = spawn(this.options.command, this.options.args ?? [], {
      cwd: this.options.cwd,
      env: this.options.env ?? process.env,
      stdio: ['pipe', 'pipe', 'pipe'],
    })
    this.child = child
    child.once('error', (error) => {
      this.spawnError = error
      // A spawn failure destroys the pipes without an input 'end' edge, so the
      // transport's pending requests must be failed here.
      this.transport?.close()
      this.failSubscriptions(this.closedError('DeepSeek Harness runtime failed to start'))
    })
    // Writes racing the runtime's death EPIPE on stdin; the exit edge below is
    // the real signal, so the stream-level error only needs to be non-fatal.
    // The timing of that race is not deterministically reproducible.
    /* v8 ignore next */

View on GitHub (pinned to b150a551b8)

Solutions

1. Create a new client instance; a closed client cannot be reused.

When it happens

Trigger: Thrown at packages/sdk/client/src/client.ts:204 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/27601c1bc50cb9a9. Report an issue: GitHub.