Claude on RunAPI

Use Anthropic Messages at https://runapi.ai with POST /v1/messages as the primary protocol.

Primary protocol recipe

Authenticate

Set ANTHROPIC_API_KEY to a RunAPI API key and ANTHROPIC_BASE_URL to https://runapi.ai. The SDK sends x-api-key; Bearer authentication is also accepted.

Send request

import anthropic
client = anthropic.Anthropic(api_key="YOUR_RUNAPI_TOKEN", base_url="https://runapi.ai")
message = client.messages.create(
    model="claude-sonnet-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Explain this decision."}],
)
print(message.content[0].text)
print(message.usage)

max_tokens is required. For long output, use client.messages.stream(...) and consume stream.text_stream through the terminal event. Add image blocks, function tools, reasoning controls, or token counting only when the current RunAPI contract verifies them for the selected exact model.

Verify result

Require final text, stop_reason, and authoritative usage. A stream is complete only after terminal Usage and message_stop. Token counting estimates input only; actual response Usage remains authoritative.

Stop boundaries

Correct a rejected shape once using the structured error. Retry transport once only before any response or Usage and when replay is safe. Record a terminal error and stop without changing model or protocol.

Compatibility protocols

Load compatibility protocols only when an existing client requires OpenAI Chat/Responses or Gemini contents.

Supported models

References

• https://runapi.ai/models/claude.md
• https://runapi.ai/providers/anthropic.md
• https://runapi.ai/models.md