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.

import os
from anthropic import Anthropic

client = Anthropic(
    api_key=os.environ["SANDBASE_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 forwarded upstream and defaults to 2023-06-01 when omitted. Optional anthropic-beta values are also forwarded, subject to provider 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. SandBase also forwards keepalive and provider-defined beta events. Consumers should ignore unknown event types for forward compatibility and handle protocol-level error events.

Compatibility

SandBase maps the public model name to the selected provider. Other compatible request fields and response bytes are preserved unless that provider has an explicit compatibility rule that removes an unsupported field or rejects the candidate. Provider-specific beta features may not be available on every model. For the complete request and response schema, see Create Anthropic Message.