Claude Opus 5

POST/v1/messages

Claude Opus 5 is the most powerful model in the Claude 5 family from Anthropic. It excels at complex reasoning, analysis, and creative tasks with superior accuracy and nuance. It supports text, image, and file inputs with text output, reasoning support and a 1M-token context window.

Request body

Parameters supported by this model. Values, defaults, and limits are read from the model registry.

stringmodelrequired

Model identifier. Set to anthropic/claude-opus-5.

Default: anthropic/claude-opus-5

array<object>messagesrequired

Conversation messages in system, user, or assistant order.

Optional<integer>max_tokens

Maximum number of tokens the model may generate in the response.

Range: −∞ to 128000

Optional<number>temperature

Sampling temperature. Lower values are more deterministic; higher values are more creative.

Range: 0 to 2

Default: 1

Optional<boolean>stream

When true, returns incremental Server-Sent Events instead of one completed response.

Default: false

Optional<array>tools

Tool definitions that the model may call during the response.

Optional<string>tool_choice

Controls whether the model may call a tool and, when supported, which tool it must call.

Optional<object>response_format

Controls the response format, including JSON mode or structured JSON output when supported.

Optional<array<string>>stop

Sequences that stop generation when the model produces one of them.

Response Schema

Fields returned by this model API response.

array<object>contentrequired

Assistant content blocks.

stringidrequired

Unique message identifier.

stringmodelrequired

Model that generated the message.

stringrolerequired

Message role returned by the assistant.

Optional<string>stop_reason

Reason generation stopped.

stringtyperequired

Response object type.

Model capabilities

array<string>capability_tagsrequired

Capabilities declared by the model registry.

Default: chat, vision, reasoning, structured_output, function_calling

integercontext_lengthrequired

Maximum context window accepted by this model.

Default: 1000000 tokens

stringexecution_moderequired

Execution mode declared by the model registry.

Default: sync

curl -X POST https://api.sandbase.ai/v1/messages \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "anthropic/claude-opus-5",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Describe this product in one sentence."
    }
  ]
}'

Response200 OK

{
  "id": "msg_abc123",
  "type": "message",
  "role": "assistant",
  "model": "anthropic/claude-opus-5",
  "content": [
    {
      "type": "text",
      "text": "A concise product description."
    }
  ],
  "stop_reason": "end_turn"
}