### September 14, 2026
The whole hunk
from line 12, old and new numbered
/
lines
from line 12
1212 For updates to Claude Code, see the [complete CHANGELOG.md](https://github.com/anthropics/claude-code/blob/main/CHANGELOG.md) in the `claude-code` repository.
1313</Tip>
1414
15### September 14, 2026
16
17* The Messages API can now [compact a conversation on demand](https://platform.claude.com/docs/en/build-with-claude/compaction#compact-on-demand-with-the-compaction-parameter) on the Claude API, in beta with the `compact-2026-09-04` beta header. Send the top-level `compaction` parameter, and the API returns a signed `compaction` block that summarizes the messages you sent. On later requests, send that block first, in place of those messages. You choose when to compact, the request can run in the background, and you can keep recent turns word for word after the summary. On models with preserved thinking, the thinking in those kept turns can stay valid.
18
1519### September 10, 2026
1620
1721* Claude Managed Agents permission policies now include `auto`: the server evaluates each agent or MCP tool call and runs it, denies it, or pauses for your approval. `agent.tool_use` and `agent.mcp_tool_use` events report how each call was evaluated in an `evaluation` field alongside `evaluated_permission`. See [Let the server evaluate each call with `auto`](https://platform.claude.com/docs/en/managed-agents/permission-policies#let-the-server-evaluate-each-call-with-auto).