Responses API

Overview

GoModel exposes OpenAI-compatible Responses API endpoints under /v1/responses. Create requests use the translated model routing pipeline, so virtual models, workflows, guardrails, failover, usage logging, and response caching continue to apply. Lifecycle and utility endpoints use native provider capabilities when available, and return explicit compatibility errors when the selected provider does not support the requested operation. For feature-level behavior, including hosted tools and chat-translated providers, see Responses compatibility.

Supported endpoints

Endpoint	Behavior
`POST /v1/responses`	Creates a response through translated model routing. Non-streaming responses are stored for later retrieval.
`GET /v1/responses/{id}`	Returns a stored gateway response when available. Otherwise, proxies to a native provider lookup when supported.
`GET /v1/responses/{id}/input_items`	Returns normalized input items captured from the original create request when available. Otherwise, proxies to a native provider lookup when supported.
`POST /v1/responses/{id}/cancel`	Cancels the response through the native provider when supported.
`DELETE /v1/responses/{id}`	Deletes the stored gateway response. When the provider supports native deletion, GoModel also forwards the delete request upstream.
`POST /v1/responses/input_tokens`	Counts input tokens through the native provider utility endpoint when supported.
`POST /v1/responses/compact`	Compacts a response input through the native provider utility endpoint when supported.

Stored responses

For non-streaming POST /v1/responses calls, GoModel stores the normalized response body and the normalized input items from the request. This enables:

GET /v1/responses/{id} for responses created through GoModel.
GET /v1/responses/{id}/input_items for the original normalized input.
DELETE /v1/responses/{id} even when the provider does not expose native response deletion.

Streaming responses are not stored as response snapshots.

Native provider lookup

When a response was not created through the current GoModel process or response store, lifecycle endpoints can still use a native provider lookup. Specify the provider when the response ID is not stored locally:

GET /v1/responses/resp_abc123?provider=openai

Without a stored response or provider hint, GoModel checks providers that expose native Responses lifecycle support. If lifecycle routing is unavailable, GoModel returns a compatibility error. If lifecycle routing is available but no provider can serve the response, GoModel returns a normal not-found error.

Input items

GoModel normalizes stored input into OpenAI-compatible response input items. String input becomes a user message with an input_text content item:

{
  "type": "message",
  "role": "user",
  "content": [
    {
      "type": "input_text",
      "text": "hello"
    }
  ]
}

Structured input arrays preserve message, function call, and function call output items where possible.

Compatibility errors

Some providers do not support every Responses lifecycle or utility endpoint. When the selected provider cannot perform an operation, GoModel returns an OpenAI-compatible error with:

{
  "error": {
    "type": "invalid_request_error",
    "message": "response compaction is not supported by this provider",
    "param": null,
    "code": "unsupported_response_operation"
  }
}

GoModel uses OpenAI’s invalid_request_error type for unsupported operations so the public error type set stays closed. The unsupported_response_operation code identifies the unsupported operation, returned with HTTP 501 Not Implemented.

Example

Create a response:

curl http://localhost:8080/v1/responses \
  -H "Authorization: Bearer $GOMODEL_MASTER_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5-mini",
    "input": "Write one short sentence about reliable gateways."
  }'

Retrieve it later:

curl http://localhost:8080/v1/responses/resp_abc123 \
  -H "Authorization: Bearer $GOMODEL_MASTER_KEY"

List its stored input items:

curl http://localhost:8080/v1/responses/resp_abc123/input_items \
  -H "Authorization: Bearer $GOMODEL_MASTER_KEY"

Getting Started

Features

MCP Proxy

Advanced

About

Overview

Supported endpoints

Stored responses

Native provider lookup

Input items

Compatibility errors

Example

​Overview

​Supported endpoints

​Stored responses

​Native provider lookup

​Input items

​Compatibility errors

​Example

Overview

Supported endpoints

Stored responses

Native provider lookup

Input items

Compatibility errors

Example