deepseek-ai/deepseek-harness · error · Error

agent "${id}" is already registered

Error message

agent "${id}" is already registered

What it means

Error "agent "${id}" is already registered" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/core/agent/src/index.ts:482

   * calling {@link announce}. Ordinary callers use {@link register}.
   * @param agent - the prepared, unpublished agent.
   * @param owner - live agent whose scoped context created this agent, or
   *   undefined for a top-level runtime root. This is runtime ownership, not
   *   the resumed session's durable parent lineage.
   * @returns an idempotent closure that removes this exact entry and emits
   *   `agent/disposed` with listener failures contained. When called from a
   *   synchronous `agent/created` listener, removal and disposal wait until
   *   that creation dispatch unwinds.
   */
  enter(agent: Agent, owner: Agent | undefined): () => void {
    const id = agent.id
    if (id !== agent.session.id) {
      throw new Error(`agent id "${id}" does not match session id "${agent.session.id}"`)
    }
    const carrier = scopeTarget(agent, agent)
    // This is the authoritative collision boundary. Concurrent create/resume
    // operations may both prepare, but only one exact entry can publish.
    if (this.store.has(id)) throw new Error(`agent "${id}" is already registered`)
    const entry: AgentEntry = {
      id,
      agent,
      owner,
      carrier,
      announced: false,
      announcing: false,
      detachRequested: false,
    }
    this.store.set(id, entry)
    let entered = true
    const detach = (): void => {
      if (!entered) return
      entered = false
      // Every callback reached by this creation dispatch must observe the same
      // live entry, and disposal must follow creation. A listener may own
      // the advanced detach capability, so make that ordering structural:
      // visibility and the paired disposal are deferred until announce()'s

View on GitHub (pinned to b150a551b8)

Solutions

1. Use a unique agent id or unregister the existing agent first.

When it happens

Trigger: Thrown at packages/core/agent/src/index.ts:482 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/60e738def85c9114. Report an issue: GitHub.