Anthropic's latest binary reveals 'claude-opus-5' model ID, 'mid-conversation tool changes

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Jul 24, 2026 19:01 UTC binary @anthropic-ai/claude-code-darwin-arm64

Anthropic's latest binary reveals 'claude-opus-5' model ID, 'mid-conversation tool changes' beta, and 'fast-mode' for Claude API.

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anthropic's new binary is hinting at a 'claude-opus-5' model and some interesting 'mid-conversation tool changes' in beta. could be big for conversational AI!

looks like anthropic is working on a 'fast-mode' for their claude api, supported on opus models. also, 'claude-opus-5' model id spotted. exciting stuff for devs!

⚠️ FROM COMPILED BINARY — lower confidence, verify before posting. (May include bundled-dependency strings, not just first-party changes.) @anthropic-ai/claude-code-darwin-arm64 2.1.215 -> 2.1.219: +14273 strings, -5377 strings, 73 interesting [model_id] (18) + Canonical model id used for the pricing lookup (e.g. 'claude-opus-4-7'). May differ from the raw model string this entry is keyed by (provider-specific ids, aliases). + Fast mode is available on {{OPUS_NAME}} and Opus 4.8. Only surface this if the caller's code actually uses fast mode (e.g. \`model="claude-opus-4-6-fast"\`, or \`speed="fast"\` on an unsupported model); if the word "fast" does not appear in the code, say nothing about Fast Mode. + When you see \`model="claude-opus-4-6-fast"\` (or any retired \`-fast\` model string), **the migration edit is** to move the fast-mode traffic onto {{OPUS_NAME}}, the current fast-capable default (Opus 4.8 also works if the caller is staying on that tier): + anthropic.claude-opus-5 + claude-opus-4-8[1m] + claude-opus-5 + claude-opus-5[1m] + us.anthropic.claude-opus-5 + | "opus 4", "opus 4.0" | \`claude-opus-4-0\` (deprecated \u2014 suggest \`{{OPUS_ID}}\`) | + | "opus 4.1" | \`claude-opus-4-1\` (deprecated, retires 2026-08-05 \u2014 suggest \`{{OPUS_ID}}\`) | + | Claude Opus 4.1 | \`claude-opus-4-1\` | \`claude-opus-4-1-20250805\` | Deprecated (retires 2026-08-05 \u2014 migrate to \`{{OPUS_ID}}\`) | + | \`claude-opus-4-0\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-1\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-5\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-6\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-7\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-8\` | \`{{OPUS_ID}}\` | + | \`claude-opus-4-8\` | \`{{OPUS_ID}}\`, \`{{FABLE_ID}}\`, \`{{MYTHOS_ID}}\`, or \`claude-opus-4-8\` | [feature_