fix(models): enable 1h cache TTL for fable-5 on bedrock

[steebchen]

Problem

A user reported that requesting prompt caching with ttl: "1h" works on Opus 4.7/4.8 (tokens land in cache_creation.ephemeral_1h_input_tokens) but on Claude Fable 5 the exact same request lands in ephemeral_5m_input_tokens.

Cause

The gateway gates 1h TTL forwarding for AWS Bedrock on the model mapping's cacheWriteInputPrice1h field (bedrockSupports1hTtl in packages/actions/src/prepare-request-body.ts), silently downgrading ttl: "1h" cachePoints to the 5m default when the field is absent. Fable 5's aws-bedrock mapping was missing the field (the direct anthropic mapping has it), so any Fable 5 request routed through Bedrock lost the 1h TTL — Opus 4.7/4.8 have the field on both mappings, which is why they behaved correctly.

Fix

• Add cacheWriteInputPrice1h: "20.0e-6" (2× input price, matching the direct Anthropic mapping) to Fable 5's aws-bedrock provider mapping. AWS's Fable 5 model card documents prompt caching with 5m and 1h TTLs.
• Allowlist anthropic.claude-fable-5 in the Bedrock 1h pricing spec guard.

This also fixes billing for Fable 5 Bedrock 1h cache writes (the price was previously undefined). Geo-region (us) pricing gets the ×1.1 premium automatically via region expansion.

Testing

• pnpm test:unit passes (the previously failing chat-projects specs were a stale local test-DB schema, fixed by pnpm push-test)
• pnpm build passes

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features
  • Added support for a new model option in AWS Bedrock pricing, including 1-hour cache write pricing.
• Bug Fixes
  • Updated eligibility checks so pricing details are only shown for models that support 1-hour cache TTLs.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 1e9be53d-4ae3-479a-9c97-6cefb6836147

📥 Commits

Reviewing files that changed from the base of the PR and between cac7441 and 7e13655.

📒 Files selected for processing (2)

• apps/gateway/src/lib/anthropic-pricing.spec.ts
• packages/models/src/models/anthropic.ts

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Walkthrough

This PR adds a cacheWriteInputPrice1h pricing field to the claude-fable-5 model's aws-bedrock provider configuration and adds the corresponding anthropic.claude-fable-5 prefix to the ONE_HOUR_BEDROCK_PREFIXES allowlist in the associated pricing test.

Changes

Bedrock 1h Pricing Update

Layer / File(s)	Summary
Model pricing and eligibility test packages/models/src/models/anthropic.ts, apps/gateway/src/lib/anthropic-pricing.spec.ts	Adds cacheWriteInputPrice1h: "20.0e-6" to the claude-fable-5 aws-bedrock provider config and adds anthropic.claude-fable-5 to the ONE_HOUR_BEDROCK_PREFIXES test allowlist.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Possibly related PRs

• theopenco/llmgateway#2609: Both PRs update the Claude Fable 5 AWS Bedrock model pricing by adding cacheWriteInputPrice1h, with the ONE_HOUR_BEDROCK_PREFIXES allowlist also extended.
• theopenco/llmgateway#2868: Both PRs update the same Bedrock 1-hour TTL pricing gating in the pricing test and the corresponding model pricing config.
• theopenco/llmgateway#2607: Both PRs modify the claude-fable-5 Anthropic aws-bedrock provider entry including cache-related pricing fields.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: enabling 1h cache TTL support for Fable 5 on Bedrock.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fable5-1h-cache-ttl-ignored

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[Copilot]

Pull request overview

Enables AWS Bedrock forwarding and billing for 1-hour prompt-cache TTL (ttl: "1h") for the Anthropic Claude Fable 5 model by adding the missing 1h cache write pricing field and updating the Bedrock 1h pricing-spec allowlist.

Changes:

• Add cacheWriteInputPrice1h to the Claude Fable 5 aws-bedrock provider mapping (aligning with the direct Anthropic mapping and enabling 1h TTL support gating).
• Allowlist anthropic.claude-fable-5 in the Bedrock 1h pricing guard test to permit cacheWriteInputPrice1h for that model on Bedrock.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/models/src/models/anthropic.ts	Adds Bedrock 1h cache-write price for Claude Fable 5 so 1h TTL can be forwarded/billed correctly.
apps/gateway/src/lib/anthropic-pricing.spec.ts	Extends the Bedrock 1h TTL allowlist to include Fable 5 so the pricing-spec guard matches the new mapping.

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