Claude API vs Router.com (Ramp Router)

Claude API

Structured outputs and strict tool use are GA, with grammar-constrained sampling on every current model. Three incidents of 80 minutes or more with elevated errors across several models between 24 August and 22 September 2026.

Router.com (Ramp Router)

Detailed Markdown docs with typed error codes, per-model capability data and routing an agent can set per request. No OpenAPI document, status page, changelog or published rate limits were found. Signup needs a US business email in a browser, and Ramp records prompts and outputs for a year by default unless switched off.

Claude API

1. Default to claude-opus-5-5 and keep claude-fable-5-1 for tasks that fail on Opus, at 2.5 times the price
2. Don't send tool_choice any or tool to Opus 5.5, Sonnet 5.5 or Fable 5.1. Use auto with strict: true on the tool
3. Put cache_control on the system prompt and tool list. Reads cost 0.05x input on Opus 5.5
4. Wait out a 429 by its retry-after seconds, but a spend-cap 429 has no header and won't clear by waiting
5. Move off claude-sonnet-4-5-20250929 before 2026-11-30. Retired ids fail, they don't redirect
6. Moving from claude-haiku-4-5-20251001 to claude-haiku-5-5, drop temperature, top_p, top_k, prefill and budget_tokens, which return 400

Router.com (Ramp Router)

1. Switch off content recording in Settings before sending private data. It is on by default and keeps prompts and outputs for a year
2. Read model ids from GET /v1/models at runtime. Ids are account-specific, an unknown one is a 404, and Gemini ids need your own Google key
3. Use POST /v1/responses with a models list for fallbacks. Router stops falling back once a stream has started
4. Set fallback_timeout and provider_timeout, or allow_flex_tier: false, when latency matters. Flex routing is on by default
5. Treat both 401 invalid_api_key and 401 api_key_deactivated as a possibly locked key, and stop retrying on 402