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Sweep 28 Aug 2026 ยท 00:00Z Build v2.1.250 478 read Stable v2.1.236 Latest v2.1.250 Next v2.1.250 Feeds RSS JSON llms.txt

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.

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API usage primer for Claude

claude_api_primer

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claude_api_primer Changed · +8 / -8 lines

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 ### Basic request and response
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant messages create \
     --model claude-opus-5 \
from line 66
 
 The Messages API is stateless, which means that you always send the full conversational history to the API. You can use this pattern to build up a conversation over time. Earlier conversational turns don't necessarily need to actually originate from Claude. You can use synthetic `assistant` messages.
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant messages create <<'YAML'
   model: claude-opus-5
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   Claude 4.6 and later models and Claude Mythos Preview do not support assistant message prefill; requests to those models must end with a user message. The examples below use a model that supports prefill.
 </Note>
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant messages create <<'YAML'
   model: claude-sonnet-4-5
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 Claude can read both text and images in requests. Both `base64` and `url` source types are supported for images, along with the `image/jpeg`, `image/png`, `image/gif`, and `image/webp` media types.
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   IMAGE_URL="https://platform.claude.com/docs/images/vision-example.jpg"
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 When thinking is on, Claude creates `thinking` content blocks where it outputs its internal reasoning. The API response includes `thinking` content blocks, followed by `text` content blocks.
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant messages create \
     --transform content --format yaml <<'YAML'
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 ### Preserving thinking blocks
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   # First request: capture the assistant content array (thinking + tool_use
   # blocks, signatures intact) as compact JSON.
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 On older models that use manual extended thinking (Claude 4, 4.5, and Sonnet 4.6 models), enable interleaved thinking by adding the beta header `interleaved-thinking-2025-05-14` to your API request:
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant beta:messages create --beta interleaved-thinking-2025-05-14 <<'YAML'
   model: claude-sonnet-4-6
from line 719
 
 ### Streaming with SDKs
 
-<CodeGroup>
+<CodeGroup exclude="shell:cURL, typescript, csharp, go, java, php, ruby">
   ```bash CLI
   ant messages create --stream --format jsonl \
     --model claude-opus-5 \