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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 Deeper second pass · 0/5 agents 427 findings $12.75 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.

One change

Quickstart

agent-sdk/quickstart

first seen The page's own history The capture it came from

Nearest release: v2.1.250, published 4 hours 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.

agent-sdk/quickstart Changed · +1 / -1 lines

from line 261
 This is what makes the Agent SDK different: Claude executes tools directly instead of asking you to implement them.
 
 <Note>
-  If you see "API key not found", make sure you've set the `ANTHROPIC_API_KEY` environment variable in the shell where you run your agent. The SDK doesn't load `.env` files automatically. See the [full troubleshooting guide](/docs/en/troubleshooting) for more help.
+  If you see an authentication error such as `Not logged in` or `Invalid API key`, make sure you've set the `ANTHROPIC_API_KEY` environment variable in the shell where you run your agent. The SDK doesn't load `.env` files automatically. See the [full troubleshooting guide](/docs/en/troubleshooting) for more help.
 </Note>
 
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