Anthropic Messages

SandBase provides an Anthropic-compatible endpoint at POST /v1/messages. Anthropic SDK applications can connect by changing the API key and base URL.

from anthropic import Anthropic

client = Anthropic(
    api_key="sk-sb-your-api-key",
    base_url="https://api.sandbase.ai",
)

Authentication and version headers

Use x-api-key or Authorization: Bearer …. When both are supplied, x-api-key takes precedence. The optional anthropic-version header is accepted for SDK compatibility.

Messages and content blocks

Messages use user and assistant roles. Put the system instruction in the top-level system field. Content can be plain text or an array of typed blocks such as text, image, tool_use, and tool_result.

Tools and extended thinking

Add tool definitions in tools and control selection through tool_choice. When supported by the selected model, configure extended reasoning with thinking; preserve returned thinking blocks when continuing the conversation.

Streaming

Set stream: true to receive Anthropic-style SSE events, including message_start, content-block events, message_delta, and message_stop. Consumers should ignore unknown event types for forward compatibility.

Compatibility

SandBase normalizes requests across multiple providers. Provider-specific beta features may not be available on every model. For the complete request and response schema, see Create Anthropic Message.