Create a preset from a messages request body | OpenRouter

curl -X POST https://openrouter.ai/api/v1/presets/my-preset/messages \
     -H "Authorization: Bearer <token>" \
     -H "Content-Type: application/json" \
     -d '{
  "messages": [
    {
      "content": "Hello!",
      "role": "user"
    }
  ],
  "model": "anthropic/claude-4.6-sonnet",
  "max_tokens": 1024,
  "system": "You are a helpful assistant."
}'

{
  "data": {
    "created_at": "2026-04-20T10:00:00Z",
    "creator_user_id": "user_2dHFtVWx2n56w6HkM0000000000",
    "description": null,
    "designated_version": {
      "config": {
        "max_tokens": 1024,
        "model": "anthropic/claude-4.6-sonnet"
      },
      "created_at": "2026-04-20T10:00:00Z",
      "creator_id": "user_2dHFtVWx2n56w6HkM0000000000",
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "preset_id": "650e8400-e29b-41d4-a716-446655440001",
      "system_prompt": "You are a helpful assistant.",
      "updated_at": "2026-04-20T10:00:00Z",
      "version": 1
    },
    "designated_version_id": "550e8400-e29b-41d4-a716-446655440000",
    "id": "650e8400-e29b-41d4-a716-446655440001",
    "name": "my-preset",
    "slug": "my-preset",
    "status": "active",
    "status_updated_at": null,
    "updated_at": "2026-04-20T10:00:00Z",
    "workspace_id": "750e8400-e29b-41d4-a716-446655440002"
  }
}

Creates a preset (or a new version of an existing one) from an inference request body. Only fields that overlap with the preset config are persisted; other fields (e.g. messages, stream, prompt) are silently ignored.

Authentication

AuthorizationBearer

API key as bearer token in Authorization header

Path parameters

slugstringRequired>=1 character

URL-safe slug identifying the preset. Created if it does not exist.

Request

This endpoint expects an object.

messageslist of objects or nullRequired

modelstringRequired

cache_controlobjectOptional

Enable automatic prompt caching. When set at the top level, the system automatically applies cache breakpoints to the last cacheable block in the request. Currently supported for Anthropic Claude models.

context_managementobject or nullOptional

max_tokensintegerOptional

metadataobjectOptional

modelslist of stringsOptional

output_configobjectOptional

Configuration for controlling output behavior. Supports the effort parameter and structured output format.

pluginslist of objectsOptional

Plugins you want to enable for this request, including their settings.

providerobjectOptional

When multiple model providers are available, optionally indicate your routing preference.

routeanyOptional

service_tierstringOptional

session_idstringOptional<=256 characters

A unique identifier for grouping related requests (e.g., a conversation or agent workflow). When provided, OpenRouter uses it as the sticky routing key, routing all requests in the session to the same provider to maximize prompt cache hits. Also used for observability grouping. If provided in both the request body and the x-session-id header, the body value takes precedence. Maximum of 256 characters.

speedenumOptional

stop_sequenceslist of stringsOptional

stop_server_tools_whenlist of objectsOptional

Stop conditions for the server-tool agent loop. Any condition firing halts the loop (OR logic). When set, this overrides max_tool_calls.

streambooleanOptional

systemstring or list of objectsOptional

temperaturedoubleOptional

thinkingobjectOptional

tool_choiceobjectOptional

toolslist of objectsOptional

top_kintegerOptional

top_pdoubleOptional

traceobjectOptional

Metadata for observability and tracing. Known keys (trace_id, trace_name, span_name, generation_name, parent_span_id) have special handling. Additional keys are passed through as custom metadata to configured broadcast destinations.

userstringOptional<=256 characters

A unique identifier representing your end-user, which helps distinguish between different users of your app. This allows your app to identify specific users in case of abuse reports, preventing your entire app from being affected by the actions of individual users. Maximum of 256 characters.

Response

Preset created or updated successfully.

dataobject

A preset with its currently designated version.

Errors

400

Bad Request Error

401

Unauthorized Error

403

Forbidden Error

404

Not Found Error

409

Conflict Error

500

Internal Server Error