KeyoAPI
Claude Sonnet 5.5 API — Balanced Coding Lane on KeyoAPI
Claude Sonnet 5.5 on KeyoAPI is the balanced lane of the Claude 5.5 family — coding and reasoning for everyday development and agent loops.
Overview
Claude Sonnet 5.5 on KeyoAPI is the balanced lane of the Claude 5.5 family — coding and reasoning for everyday development and agent loops.
Indicative rates are about $0.88 / $4.41 per 1M in/out — confirm live on /pricing-list. For most agent loops and code generation the balance lands here: strong enough on multi-step reasoning, still far below the Opus and Fable tiers (~$1.76 / $8.82 and ~$7.35 / $36.77). If a step does not need Sonnet-class reasoning, route it to claude-haiku-5-5 (~$0.07 / $0.37) or gpt-6-luna (~$0.03 / $0.15) on the same key.
How to call: keep your OpenAI SDK and set the base URL to https://www.keyoapi.xyz/v1, then pass model=claude-sonnet-5-5 to POST /v1/chat/completions with your Bearer key.
The full Claude comparison lives on /claude-api-pricing. All metered rows: /pricing-list.
Quick start
Base URL: https://www.keyoapi.xyz/v1
Endpoint: POST /v1/chat/completions
Model: model=claude-sonnet-5-5
curl https://www.keyoapi.xyz/v1/chat/completions \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"claude-sonnet-5-5","messages":[{"role":"user","content":"Refactor this function for readability"}]}'Auth uses the same Bearer API key as chat. Full notes: Keyo docs.
FAQ
Sonnet 5.5 vs Sonnet 5?
claude-sonnet-5 is the earlier Sonnet row at ~$0.44 / $2.21 per 1M in/out; claude-sonnet-5-5 is the newer 5.5-gen row at ~$0.88 / $4.41. Start on Sonnet 5 and step up only where its failures are measurable. Confirm live on /pricing-list.
How do I integrate?
Keep your OpenAI SDK, set baseURL to https://www.keyoapi.xyz/v1, and use model=claude-sonnet-5-5.