mid-conversation-system-messages changedbuild-with-claude/mid-conversation-system-messages
Nearest release: v2.1.316, published under an hour before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+5added
Lines−5removed
From line
3
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits32to this page, all time
The whole hunk
from line 3, old and new numbered
/
from line 3
33url: https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages
44description: Change system instructions or tool availability partway through a conversation without invalidating the cached prefix that came before them.
55featureMetadata:
6 status: ga
6 status: stable
77 zdr:
88 eligibility: eligible
99 note: Excludes [Covered Models](https://platform.claude.com/docs/en/manage-claude/api-and-data-retention#model-specific-data-retention-requirements). Request-shape capability of the Messages API; mid-conversation system messages flow through the standard inference path and nothing is stored server-side after the response.
from line 19
1919 - claude-haiku-5-5
2020 - claude-opus-4-8
2121 supportedPlatforms:
22 Claude API: ga
23 Claude Platform on AWS: ga
24 Amazon Bedrock: ga
25 Claude Models on Google Cloud (Google managed): ga
22 Claude API: stable
23 Claude Platform on AWS: stable
24 Amazon Bedrock: stable
25 Claude Models on Google Cloud (Google managed): stable
2626---
2727
2828**API support**: Usage differs by product.
No line in this hunk matches that.