[DOCS] Hooks reference missing `hookSpecificOutput.sessionTitle` for `UserPromptSubmit`

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/hooks

Section/Topic

UserPromptSubmit decision control / advanced JSON output

Current Documentation

The docs currently say:

UserPromptSubmit hooks can control whether a user prompt is processed and add context. All [JSON output fields](#json-output) are available. There are two ways to add context to the conversation on exit code 0: Plain text stdout: any non-JSON text written to stdout is added as context JSON with additionalContext: use the JSON format below for more control. The additionalContext field is added as context

The guide currently says:

For UserPromptSubmit hooks, use additionalContext instead to inject text into Claude's context.

The Agent SDK type reference currently shows only additionalContext for UserPromptSubmit output:

class UserPromptSubmitHookSpecificOutput(TypedDict): hookEventName: Literal["UserPromptSubmit"] additionalContext: NotRequired[str]

What's Wrong or Missing?

Changelog v2.1.94 added hookSpecificOutput.sessionTitle to UserPromptSubmit hooks for setting the session title, but the current docs still present additionalContext as the only documented UserPromptSubmit-specific output. There is no documented field name, schema entry, JSON example, or behavior guidance for setting a session title from a hook, and the Agent SDK type definitions are stale for the same reason.

Suggested Improvement

Update the UserPromptSubmit hook docs everywhere the output schema is described:

• Add hookSpecificOutput.sessionTitle to the field table and JSON examples on https://code.claude.com/docs/en/hooks
• Update https://code.claude.com/docs/en/hooks-guide so it no longer implies additionalContext is the only UserPromptSubmit-specific output
• Add sessionTitle to the Python and TypeScript Agent SDK UserPromptSubmit output types and related hook overview tables
• Document how hook-set titles interact with existing naming mechanisms such as --name, /rename, and auto-generated titles

For example, the hooks reference should include a UserPromptSubmit example like:

{
"hookSpecificOutput": {
"hookEventName": "UserPromptSubmit",
"sessionTitle": "auth-refactor"
}
}

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Line(s) | Context |
|------|---------|---------|
| https://code.claude.com/docs/en/hooks | 820-845 | UserPromptSubmit decision control documents additionalContext but not sessionTitle |
| https://code.claude.com/docs/en/hooks-guide | 503-505 | Guide says to use additionalContext for UserPromptSubmit hooks |
| https://platform.claude.com/docs/en/agent-sdk/hooks | 143-149 | Hook summary describes UserPromptSubmit as injecting additional context into prompts |
| https://platform.claude.com/docs/en/agent-sdk/python | 2087-2089 | UserPromptSubmitHookSpecificOutput omits sessionTitle |
| https://platform.claude.com/docs/en/agent-sdk/typescript | 1221-1224 | UserPromptSubmit hook output union omits sessionTitle |
| https://platform.claude.com/docs/en/agent-sdk/agent-loop | 287-292 | Hook summary only mentions injecting additional context |

Total scope: 6 pages affected

Source: Changelog v2.1.94

Changelog entry: Added hookSpecificOutput.sessionTitle to UserPromptSubmit hooks for setting the session title