Source Intelligence
Sweep 28 Aug 2026 · 00:00Z Build v2.1.250 478 read Stable v2.1.236 Latest v2.1.250 Next v2.1.251 Feeds RSS JSON llms.txt
Reading a new release v2.1.251 Analysing changes · 2/5 Sorting the findings · 1/4 steps 470 findings $18.91 so far

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

Prompt capture

v2.1.129 system prompt

2 added and 2 removed, of 217 lines, about 46 words, in the prompt all 27 arms receive. 1 of 23 tool descriptions changed. Compared against v2.1.128.

The two arm counts on this page measure different things: 27 arms receive the prompt the headline is about, and the widest edit below reached 1, because the same changed lines sit in more than one prompt.

Agent SDK, print mode 27 model strings 23 tools released captured Markdown

- You are powered by the model named Opus 4.7 (1M context). The exact model ID is claude-opus-4-7[1m].

System prompt, reached 1 of 27 arms +2 −2 of 217 lines

This edit reached 1 of 27 arms: (unset)

from line 207
  - Platform: linux
  - Shell: unknown
  - OS Version: Linux 5.15.0-187-generic
- - You are powered by the model named Sonnet 4.6. The exact model ID is claude-sonnet-4-6.
- - Assistant knowledge cutoff is August 2025.
+ - You are powered by the model named Opus 4.7 (1M context). The exact model ID is claude-opus-4-7[1m].
+ - Assistant knowledge cutoff is January 2026.
  - The most recent Claude model family is Claude 4.X. Model IDs — Opus 4.7: 'claude-opus-4-7', Sonnet 4.6: 'claude-sonnet-4-6', Haiku 4.5: 'claude-haiku-4-5-20251001'. When building AI applications, default to the latest and most capable Claude models.
  - Claude Code is available as a CLI in the terminal, desktop app (Mac/Windows), web app (claude.ai/code), and IDE extensions (VS Code, JetBrains).
  - Fast mode for Claude Code uses Claude Opus 4.6 with faster output (it does not downgrade to a smaller model). It can be toggled with /fast and is only available on Opus 4.6.

Bash, reached 1 of 27 arms +2 −2 of 123 lines

This edit reached 1 of 27 arms: (unset)

from line 63
 3. Run the following commands in parallel:
    - Add relevant untracked files to the staging area.
    - Create the commit with a message ending with:
-   Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
+   Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
    - Run git status after the commit completes to verify success.
    Note: git status depends on the commit completing, so run it sequentially after the commit.
 4. If the commit fails due to pre-commit hook: fix the issue and create a NEW commit
from line 80
 git commit -m "$(cat <<'EOF'
    Commit message here.
 
-   Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
+   Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
    EOF
    )"
 </example>

EnterPlanMode +1 −1 of 86 lines

This edit reached all 27 arms

from line 43
 ## What Happens in Plan Mode
 
 In plan mode, you'll:
-1. Thoroughly explore the codebase using Glob, Grep, and Read tools
+1. Thoroughly explore the codebase using Glob, Grep, and Read
 2. Understand existing patterns and architecture
 3. Design an implementation approach
 4. Present your plan to the user for approval

The full text

The whole documents, one page each, exactly as they were sent.