Claude Opus 5.5 API on KeyoAPI — Hard Agents

Claude Opus 5.5 on KeyoAPI is an Opus-class chat and agent model for hard coding and multi-step tool loops.

claude-opus-5-5 is a llm model on KeyoAPI, a prepaid AI API gateway: call it at POST /v1/chat/completions, billed at ~$1.76 / $8.82 per 1M in/out from the same balance that covers chat, vision, OCR and video models.

Listed price: ~$1.76 / $8.82 per 1M in/out · Live catalog: Model Square · Static list: pricing list.

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Overview

Indicative rates are about $1.76 / $8.82 per 1M in/out — confirm live on the full pricing list. Reserve it for escalations; keep Sonnet or cheaper chat IDs on the hot path. Same OpenAI-compatible gateway as other Keyo chat models.

Opus 5.5 pricing by input and output tokens

The public KeyoAPI catalog checked on 2026-10-13 lists default-group rates of $1.7647 per million input tokens and $8.8235 per million output tokens. These are KeyoAPI sell rates, not Anthropic official list prices. Confirm current rates and your billing-group multiplier in the pricing page.

A request with 10,000 input tokens and 2,000 output tokens costs about $0.035294 before retries, cached-token adjustments or extra modalities. A thousand requests with that identical mix cost about $35.294. For agent sessions, count tokens across every model turn and repeated context rather than only the final answer.

Fable 5.1 vs Opus 5.5

claude-fable-5-1 lists $7.3530 input and $36.7650 output per million tokens in the checked default group, about 4.17 times the Opus rate. The same example costs $0.147060 on Fable. Fable 5.1 vs Opus 5.5 covers both comparison word orders with one table and one evaluation checklist.

Test both models on the same coding or agent tasks with the same context, tools and execution budget. Compare passing tests, completed tasks, human corrections and total cost including retries. Use measured results to decide when a higher-cost candidate is worth routing to; this guide does not claim a universal performance ranking.

Call opus5.5 through the chat API

The shorthand opus5.5 maps to claude-opus-5-5 in this guide. Keep the exact catalog ID in your request. Both Opus and Fable currently advertise the OpenAI-compatible chat route; verify advanced tool and streaming behavior before deploying it.

Use Build an AI agent with the KeyoAPI chat API for a bounded application loop and the Claude API pricing page for the broader Claude-class rate table. Your application executes tools and checks results; a chat response does not run the agent workflow by itself.

Listed price: ~$1.76 / $8.82 per 1M in/out
Billing base: $1 of wallet balance = 500,000 quota units
Gift credit: new users get $10, invites add $3 (spend-first on :free IDs)
Endpoint: POST /v1/chat/completions with Bearer auth on https://www.keyoapi.xyz/v1

How to call it

Base URL: https://www.keyoapi.xyz/v1

Endpoint: POST /v1/chat/completions

Model: model=claude-opus-5-5

curl https://www.keyoapi.xyz/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-opus-5-5","messages":[{"role":"user","content":"Hello from Claude Opus 5.5"}]}'

Auth uses the same Bearer API key as chat. Full notes: Keyo docs.

FAQ

Opus 5.5 vs Opus 5?

claude-opus-5-5 is the newer Opus-class ID (~$1.76/$8.82). claude-opus-5 remains available at a lower indicative band (~$1.10/$5.52). Confirm live on the pricing page.

How do I integrate?

Keep your OpenAI SDK, set baseURL to https://www.keyoapi.xyz/v1, and use model=claude-opus-5-5.

Is opus5.5 the API model ID?

Use claude-opus-5-5 as the model value. opus5.5 is a shorthand label, not the exact catalog ID. See Fable 5.1 vs Opus 5.5 to compare it with claude-fable-5-1.

Guide for claude-opus-5-5. Catalog: the pricing page · Rates: the full pricing list.