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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
HomeDocsClaude Developer Platform 21 Oct 2026
One change · api

parallel-tool-use changedagents-and-tools/tool-use/parallel-tool-use

Nearest release: v2.1.307, published an hour after 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+8added
Lines−8removed
From line 738 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits10to this page, all time

The whole hunk

from line 738, old and new numbered
/
lines
from line 738
738738 
739739 puts "Requesting parallel tool calls..."
740740 response = client.messages.create(
741 model: "claude-opus-5-5",
741 model: Anthropic::Model::CLAUDE_OPUS_5_5,
742742 max_tokens: 1024,
743743 messages: [
744744 { role: "user", content: "What's the weather in SF and NYC, and what time is it there?" }
from line 776
776776 
777777 puts "\nGetting final response..."
778778 final_response = client.messages.create(
779 model: "claude-opus-5-5",
779 model: Anthropic::Model::CLAUDE_OPUS_5_5,
780780 max_tokens: 1024,
781781 messages: [
782782 { role: "user", content: "What's the weather in SF and NYC, and what time is it there?" },
from line 847
847847 
848848### At most one tool call
849849 
850When `tool_choice` type is `auto` (the default), setting `disable_parallel_tool_use: true` means Claude calls at most one tool per response. Claude can still answer in plain text without calling any tool. The highlighted lines are the only change from a standard tool use request:
850When `tool_choice` type is `auto` (the default), setting `disable_parallel_tool_use: true` means Claude calls at most one tool in each response. Claude can still answer in plain text without calling any tool. The highlighted lines are the only change from a standard tool use request:
851851 
852852<CodeGroup>
853853 ```bash cURL
from line 1099
10991099 client = Anthropic::Client.new
11001100 
11011101 response = client.messages.create(
1102 model: "claude-opus-5-5",
1102 model: Anthropic::Model::CLAUDE_OPUS_5_5,
11031103 max_tokens: 1024,
11041104 tools: [
11051105 {
from line 1380
13801380 client = Anthropic::Client.new
13811381 
13821382 response = client.messages.create(
1383 model: "claude-opus-5",
1383 model: Anthropic::Model::CLAUDE_OPUS_5,
13841384 max_tokens: 1024,
13851385 tools: [
13861386 {
from line 1575
15751575## Next steps
15761576 
15771577<CardGroup cols={3}>
1578 <Card title="Tool Runner (SDK)" icon="wrench" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-runner">
1579 Use the SDK's Tool Runner abstraction to handle the agentic loop, error wrapping, and type safety automatically.
1578 <Card title="Tool runner (SDK)" icon="wrench" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-runner">
1579 Use the SDK's tool runner abstraction to handle the agentic loop, error wrapping, and type safety automatically.
15801580 </Card>
15811581 
15821582 <Card title="Handle tool calls" icon="arrows-left-right" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/handle-tool-calls">
1583 Parse tool\_use blocks, format tool\_result responses, and handle errors with is\_error.
1583 Parse `tool_use` blocks, format `tool_result` responses, and handle errors with `is_error`.
15841584 </Card>
15851585 
15861586 <Card title="Define tools" icon="hammer" href="https://platform.claude.com/docs/en/agents-and-tools/tool-use/define-tools">
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