mastra-ai/mastra · error

Cannot approve a tool call without a current thread

Error message

Cannot approve a tool call without a current thread

What it means

Thrown when approving a tool call while the session has no current conversation thread. `agent.sendToolApproval` requires both `threadId` and `resourceId` to persist the approval decision; the session resolves the thread via `this.thread.getId()`, and when no thread has been created/selected the approval cannot be recorded, so the library throws.

Source

Thrown at packages/core/src/agent-controller/session.ts:3757

   */
  async approveToolCall({
    toolCallId,
    requestContext: requestContextInput,
  }: {
    toolCallId?: string;
    requestContext?: RequestContext;
  }): Promise<void> {
    const runId = this.run.getRunId();
    if (!runId) {
      throw new Error('No active run to approve tool call for');
    }

    const agent = this.machinery.getAgent();
    const requestContext = await this.machinery.buildRequestContext(requestContextInput);
    const isYolo = (this.state.get() as Record<string, unknown>).yolo === true;
    const threadId = this.thread.getId();
    if (!threadId) {
      throw new Error('Cannot approve a tool call without a current thread');
    }
    const resourceId = this.identity.getResourceId();
    await agent.sendToolApproval({
      threadId,
      resourceId,
      runId,
      toolCallId,
      approved: true,
      requireToolApproval: !isYolo,
      memory: { thread: threadId, resource: resourceId },
      abortSignal: this.run.ensureAbortController().signal,
      requestContext,
      toolsets: await this.machinery.buildToolsets(requestContext),
    });
  }

  /**
   * Decline a parked tool call: drive the agent to reject it. Throws when there

View on GitHub (pinned to 75dd419e61)

Solutions

1. Ensure the session has a current thread before approving — start the run normally so the thread is created, or explicitly select/create a thread.
2. Verify thread lifecycle code isn't clearing the current thread while a run awaiting approval is still active.
3. If using multiple sessions, route the approval to the session instance that owns the originating thread.

Example fix

// before
await session.approveToolCall({ toolCallId }); // thread may be unset

// after
if (session.getCurrentThreadId?.()) {
  await session.approveToolCall({ toolCallId });
} else {
  await session.selectThread(existingThreadId);
  await session.approveToolCall({ toolCallId });
}

// before approving
const threadId = session.getCurrentThreadId?.();
if (!threadId) {
  throw new Error('Select or create a thread before approving tool calls');
}

function hasThread(session: { getCurrentThreadId?: () => string | undefined }): boolean {
  return typeof session.getCurrentThreadId === 'function' && typeof session.getCurrentThreadId() === 'string';
}

try {
  await session.approveToolCall({ toolCallId });
} catch (err) {
  if (err instanceof Error && err.message.includes('without a current thread')) {
    await session.selectThread(fallbackThreadId);
    await session.approveToolCall({ toolCallId });
  } else throw err;
}

When it happens

Trigger: Calling the approve-tool-call method on a session where `this.thread.getId()` returns undefined — i.e., no thread was created, selected, or the thread was cleared before approving.

Common situations: Creating a fresh session and approving a tool call without first starting a conversation that establishes a thread; clearing/resetting thread state mid-run; multi-session apps where the approval is routed to a session that never had its thread set.

Related errors

• Cannot decline a tool call without a current thread
• AGENT_SEND_TOOL_APPROVAL_AMBIGUOUS_SUSPENDED_RUNS
• AGENT_SEND_TOOL_APPROVAL_NO_ACTIVE_THREAD_RUN
• Received input message with wrong threadId. Input ${message.
• No active run to approve tool call for

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/8168144e1d4c5249. Report an issue: GitHub.