[DOCS] Subagent continuation docs still show the old resume flow

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/sub-agents

Section/Topic

Resume subagents / programmatic subagent continuation

Current Documentation

The code docs currently say:

To resume a subagent, ask Claude to continue the previous work:

The Agent SDK TypeScript reference still includes:

type AgentInput = { ... resume?: string; ... }

The Agent SDK subagents guide also says:

Pass resume: sessionId in the second query's options, and include the agent ID in your prompt

What's Wrong or Missing?

Claude Code v2.1.77 removed the Agent tool's resume parameter and replaced the continuation flow with SendMessage({to: agentId}).

The same release also changed SendMessage so it auto-resumes stopped agents in the background. Current docs still teach the older continuation pattern, so SDK users and advanced subagent users do not get an accurate reference for the supported API.

Suggested Improvement

Update the subagent continuation docs to distinguish session resume from agent continuation.

Suggested changes:

• remove resume from the Agent tool input/reference
• show SendMessage({to: agentId}) as the supported way to continue a previously spawned agent
• document that SendMessage auto-resumes stopped agents in the background
• clarify when session-level resume is still valid and when users need agent-level continuation instead

Impact

High - Prevents users from using a feature

Additional Context

Affected Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/sub-agents | User-facing subagent continuation section |
| https://platform.claude.com/docs/en/agent-sdk/subagents | Programmatic subagent continuation examples still describe the old flow |
| https://platform.claude.com/docs/en/agent-sdk/typescript | AgentInput still shows resume?: string |

Total scope: 3 pages affected

Source: Claude Code v2.1.77 release notes

Exact release entries:

The Agent tool no longer accepts a resume parameter - use SendMessage({to: agentId}) to continue a previously spawned agent

SendMessage now auto-resumes stopped agents in the background instead of returning an error