API docsModel reference

Claude Opus 5.5 API

Anthropic Claude Opus 5.5: frontier model for agentic coding, long-horizon tasks and deep analysis. 1M context.

POST/api/v1/chat/completionsBearer API key

claude-opus-5.5Chat · AnthropicModel details & pricing

Endpoints for this model

POST/chat/completionsChat completions GET/models/{slug}Get one model

Parameter scope

Select a provider to see its effective parameter limits. Automatic routing chooses a provider that supports your input. Examples include defaults and required inputs; replace example media URLs with accessible files.

Request

cURL

curl 'https://01router.com/api/v1/chat/completions' \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "claude-opus-5.5",
  "messages": [
    {
      "role": "user",
      "content": "Hello!"
    }
  ],
  "max_tokens": 512,
  "stream": false
}'

Input parameters

JSON body

For /generations and /quote, put these parameters inside input. For /images/generations, put them at the top level. Chat parameters go at the top level of /chat/completions.

model stringRequired: Model slug from the catalog. Project keys may use a project-specific model slug.
Allowed values:"claude-opus-5.5"
messages object[]Required: Non-empty message array with role and content; content may contain supported multimodal parts.
provider stringOptional: Optional provider slug. Omit for automatic routing; project settings may pin the provider.
project stringOptional: Optional project ID. Use its published model catalog and routing configuration.
stream booleanOptional: Default false. true returns text/event-stream chunks and ends with data: [DONE].
Default:false
max_tokens integerOptional: Positive integer. Default 4096. Do not combine with max_completion_tokens.
Default:4096
Minimum:1
max_completion_tokens integerOptional: Positive integer. Default 4096. Do not combine with max_completion_tokens.
temperature numberOptional: OpenAI-compatible sampling, tools and structured output fields depend on the selected model and provider. Only n = 1 is supported.
tools object[]Optional: OpenAI-compatible sampling, tools and structured output fields depend on the selected model and provider. Only n = 1 is supported.
response_format objectOptional: OpenAI-compatible sampling, tools and structured output fields depend on the selected model and provider. Only n = 1 is supported.

Response example

200 · application/json

{
  "id": "chat_example",
  "object": "chat.completion",
  "model": "claude-opus-5.5",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello!"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 8,
    "completion_tokens": 2,
    "total_tokens": 10
  }
}

SSE · stream: true

data: {"id":"chat_example","object":"chat.completion.chunk","choices":[{"index":0,"delta":{"content":"Hello!"},"finish_reason":null}]}

data: [DONE]

Responses are illustrative. IDs, usage, prices and results depend on the actual request.

Response fields

id string: Generation ID returned by the create request.
object string: chat.completion / chat.completion.chunk
model string: Model slug from the catalog. Project keys may use a project-specific model slug.
choices array: Completion choices. Non-streaming replies use choices[].message; streaming chunks use choices[].delta.
usage object: prompt_tokens, completion_tokens and total_tokens. Streaming includes usage when supplied by the provider.

Usage notes

OpenAI-compatible sampling, tools and structured output fields depend on the selected model and provider. Only n = 1 is supported.

Use with AI

Give your coding assistant the documentation index or the full API reference, including live model parameters.

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