Agent SDK reference - TypeScript changedagent-sdk/typescript
Nearest release: v2.1.283, published 6 hours before upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Upstream edited this page at 26 Sep 2026 01:10 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 26 Sep 2026 01:37 UTC.
Upstream edited
Recorded here
Lines+8added
Lines−2removed
From line
1,710
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits58to this page, all time
The whole hunk
from line 1710, old and new numbered
/
This page is larger than the 256 KiB this site keeps, so one side of the diff below stops where the stored text does.
from line 1710
17101710
17111711### `SDKInformationalMessage`
17121712
1713Generic text banner emitted by the loop. Carries non-error status lines, hook feedback such as a `UserPromptSubmit` hook's block reason, and command output. On Claude Code v2.1.227 or later, a hook's [`systemMessage`](/docs/en/hooks#json-output) can arrive as this message, with each line prefixed by the hook's name, such as `PostToolUse:Bash says:`. Whether a hook's `systemMessage` arrives as this message depends on the event. Each [event's section](/docs/en/hooks#hook-events) on the hooks page says how output surfaces. Render `content` as plaintext at the given `level`.
1713Generic text banner emitted by the loop. Carries warnings, notices, and other non-error status lines Claude Code raises, and hook feedback such as a `UserPromptSubmit` hook's block reason.
17141714
1715On Claude Code v2.1.227 or later, a hook's [`systemMessage`](/docs/en/hooks#json-output) can arrive as this message, with each line prefixed by the hook's name, such as `PostToolUse:Bash says:`. Each [event's section](/docs/en/hooks#hook-events) on the hooks page says how output surfaces.
1716
1717Render `content` as plaintext at the given `level`.
1718
17151719```typescript theme={null}
17161720type SDKInformationalMessage = {
17171721 type: "system";
from line 2288
22842288
22852289```typescript theme={null}
22862290type PreCompactHookInput = BaseHookInput & {
2287 hook_ev
2291 hook_event_name: "PreCompact";
2292 trigger: "manual" |
No line in this hunk matches that.