feat: add Claude Fable 5 model#1372
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Anthropic released Claude Fable 5 (`claude-fable-5`) as a GA model on 2026-06-09 — a Mythos-class, most-capable model for long-horizon agentic work (1M context, adaptive thinking always-on, no extended thinking). Expose it in both Claude model pickers: - codium Anthropic plugin: add `claude-fable-5` (full-ID list). - happy-app Claude fallback: add `claude-fable-5` to getClaudeModelModes. Fable 5 is a new family with no short alias (unlike opus/sonnet/haiku), so the picker sends the full model id; the Claude CLI passes it through to the API unchanged. The live model list still comes from the CLI's session metadata when present — this is the offline fallback. Add a getClaudeModelModes test asserting the fallback list and that the full id is used for Fable 5. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
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Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
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Small data point on the "no short alias" note — the In the bundled and it maps So on recent CLIs |
chphch
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Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
chphch
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Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
chphch
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Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
chphch
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Jun 11, 2026
Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
chphch
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Jun 11, 2026
Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
chphch
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Jun 11, 2026
Add Fable 5 — Claude's new top tier above Opus — to getClaudeModelModes() above opus 4.8. Use the full model id `claude-fable-5` (not the `fable` short alias) to match upstream PR slopus#1372 and stay portable across Claude Code versions that predate the alias. Default stays opus + ultracode; the model key passes straight to `claude --model`. Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
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What
Adds Claude Fable 5 (
claude-fable-5) to the Claude model pickers. Anthropic shipped Fable 5 as a GA model on 2026-06-09 — a Mythos-class, most-capable model for long-horizon agentic work (1M context, adaptive thinking always-on, no extended thinking).Changes
plugins/anthropic/index.ts: addclaude-fable-5to the full-IDMODELSlist (top slot).modelModeOptions.ts: addclaude-fable-5togetClaudeModelModes()fallback.opus/sonnet/haiku), so the picker sends the full model id; the Claude CLI passes it through to the API unchanged.modelModeOptions.test.ts: new test asserting the Claude fallback list and that the full id is used for Fable 5.Verification
modelModeOptions.test.ts— 10 passedhappy-apptypecheck — passcodiumtypecheck — passFollows the same pattern as the Opus 4.8 addition (#1363).
🤖 Generated with Claude Code