Create Response

curl -X POST https://api-gateway.merge.dev/responses \
     -H "Content-Type: application/json" \
     -d '{
  "input": [
    {
      "type": "message",
      "content": "What is the capital of France?",
      "role": "user"
    }
  ],
  "model": "openai/gpt-5.1"
}'

{
  "id": "resp_a1b2c3d4e5f6",
  "created_at": "2026-03-23T12:00:00Z",
  "model": "openai/gpt-5.1",
  "output": [
    {
      "id": "msg_001",
      "content": [
        {
          "type": "text",
          "text": "The capital of France is Paris. It is the largest city in France and serves as the country's political, economic, and cultural center."
        }
      ],
      "type": "message",
      "role": "assistant",
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "input_tokens": 14,
    "output_tokens": 28,
    "total_tokens": 42
  },
  "object": "response",
  "vendor": "openai",
  "provider_request_id": "chatcmpl-abc123"
}

Create an LLM response.

Supports both streaming and non-streaming modes via the stream parameter.

curl -X POST https://api-gateway.merge.dev/responses \
     -H "Content-Type: application/json" \
     -d '{
  "input": [
    {
      "type": "message",
      "content": "What is the capital of France?",
      "role": "user"
    }
  ],
  "model": "openai/gpt-5.1"
}'

{
  "id": "resp_a1b2c3d4e5f6",
  "created_at": "2026-03-23T12:00:00Z",
  "model": "openai/gpt-5.1",
  "output": [
    {
      "id": "msg_001",
      "content": [
        {
          "type": "text",
          "text": "The capital of France is Paris. It is the largest city in France and serves as the country's political, economic, and cultural center."
        }
      ],
      "type": "message",
      "role": "assistant",
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "input_tokens": 14,
    "output_tokens": 28,
    "total_tokens": 42
  },
  "object": "response",
  "vendor": "openai",
  "provider_request_id": "chatcmpl-abc123"
}

Create an LLM response.

Supports both streaming and non-streaming modes via the stream parameter.

Request

This endpoint expects an object.

inputlist of objectsRequired

Conversation history

modelstring or nullOptional

Model ID in format ‘provider/model-name’. Optional if a routing policy is configured.

toolslist of objects or nullOptional

Available tools

tool_choicestring or map from strings to any or nullOptional

Tool choice policy: ‘auto’, ‘none’, ‘required’, or {‘type’: ‘function’, ‘function’: {‘name’: ’…’}}

max_tokensinteger or nullOptional

Maximum tokens to generate

temperaturedouble or nullOptional0-2

Sampling temperature

top_pdouble or nullOptional0-1

Nucleus sampling parameter

stoplist of strings or nullOptional

Stop sequences

response_formatobject or nullOptional

Response format

streambooleanOptionalDefaults to false

Whether to stream the response

tagslist of objects or nullOptional

Tags to attach to this request for categorization (key-value pairs)

project_idstring or nullOptional

Optional project ID (UUID) to associate with this request

routing_policy_idstring or nullOptional

Override the default routing policy (for testing)

include_routing_metadatabooleanOptionalDefaults to false

Include detailed routing metadata in response

vendorstring or nullOptional

Restrict routing to a specific vendor (hosting platform)

vendorslist of strings or nullOptional

Ordered list of acceptable vendors. First available wins.

Response

Successful Response

idstring

created_atdatetime

modelstring

The model that generated the response, in ‘provider/model-name’ format

outputlist of objects

usageobject

Token usage statistics.

object"response"

vendorstring or null

The execution vendor that served the request

provider_request_idstring or null

The upstream provider's request ID

routingobject or null

Routing metadata (only present when include_routing_metadata=true)

Errors

422

Unprocessable Entity Error

$	curl -X POST https://api-gateway.merge.dev/responses \
>	-H "Content-Type: application/json" \
>	-d '{
>	"input": [
>	{
>	"type": "message",
>	"content": "What is the capital of France?",
>	"role": "user"
>	}
>	],
>	"model": "openai/gpt-5.1"
>	}'

1	{
2	"id": "resp_a1b2c3d4e5f6",
3	"created_at": "2026-03-23T12:00:00Z",
4	"model": "openai/gpt-5.1",
5	"output": [
6	{
7	"id": "msg_001",
8	"content": [
9	{
10	"type": "text",
11	"text": "The capital of France is Paris. It is the largest city in France and serves as the country's political, economic, and cultural center."
12	}
13	],
14	"type": "message",
15	"role": "assistant",
16	"finish_reason": "stop"
17	}
18	],
19	"usage": {
20	"input_tokens": 14,
21	"output_tokens": 28,
22	"total_tokens": 42
23	},
24	"object": "response",
25	"vendor": "openai",
26	"provider_request_id": "chatcmpl-abc123"
27	}