Responses API - LETHE

POST https://asklethe.ai/v1/responses accepts the same request shape as OpenAI’s Responses API (input instead of messages, structured output items, etc.). Use this if your client already targets the Responses API rather than Chat Completions.

curl https://asklethe.ai/v1/responses \
  -H "Authorization: Bearer $LETHE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "lethe",
    "input": "Say hi in five words."
  }'

When to use this vs. Chat Completions

Use Chat Completions if your tooling (LangChain, CrewAI, most SDKs) expects the messages array shape.
Use Responses if you’re already on OpenAI’s newer Responses API and want to keep that request/response shape.

Both endpoints share the same authentication, quota, model resolution (lethe / lethe-vision), and error format. See Authentication, Rate Limits, and Errors. Vision input (input_image / input_video items) requires model: "lethe-vision", same rule as Chat Completions.

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