> ## Documentation Index > Fetch the complete documentation index at: https://docs.reilabs.org/llms.txt > Use this file to discover all available pages before exploring further. # Chat completion Generate a chat completion with a Reigent. * **URL**: `/v1/chat/completions` * **Method**: `POST` * **Headers**: | Key | Value | | - | - | | Authorization | Bearer [**rei-agent-secret-token**](/docs/api-and-sdk/quickstart/#unit-api-key) | * ## **Request**: **model** `string` Optional *Default*: Agent's Configured Model *Allowed values*: * `google/gemini-2.5-flash` *** **messages** `array` (min length: 1) Required
Show message structure Each message object contains: **role** `string` Required\ The role of the message author.\ *Allowed values: `"system"`, `"user"`, `"assistant"`, `"tool"`* **content** `string` or `array` Required\ The contents of the message. Can be: * Simple text string * Array of content parts (for multimodal inputs)
Show content parts structure Each content part object contains: **type** `string` Required\ The type of content part.\ *Allowed values: `"text"`, `"image_url"`, `"file"`, `"file_url"`* **text** `string` Conditional\ Text content (required when type is `"text"`) **image\_url** `object` Conditional\ Image URL details (required when type is `"image_url"`)\ *Contains:* * **url** `string` Required\ The URL of the image
**file** `object` Conditional\ File details (required when type is `"file"`)\ *Contains:* * **filename** `string` Required\ The name of the file * **file\_data** `string` Required\ The buffer content of the file
**file\_url** `string` Conditional\ The URL of the file (required when type is `"file_url"`)
**name** `string` Optional\ An optional name for the participant **tool\_call\_id** `string` Optional\ Required when role is `"tool"` **tool\_calls** `array` Optional\ Tool calls made by the assistant
*** ## **temperature** `number` Optional *Range*: 0 to 2 *Default*: 1 ## **max\_tokens** `integer` Optional *Minimum*: 1 ## **top\_p** `number` Optional *Range*: 0 to 1 ## **n** `integer` Optional *Minimum*: 1 ## **seed** `number` Optional *Range*: 0 to 2^53-1 ## **stream** `boolean` Optional ## **stop** `string` or `array[string]` Optional ## **presence\_penalty** `number` Optional *Range*: -2.0 to 2.0 ## **frequency\_penalty** `number` Optional *Range*: -2.0 to 2.0 ## **logit\_bias** `object` Optional *Key format*: Token IDs as string numbers *Value range*: -100 to 100 ## **logprobs** `boolean` Optional ## ***top\_logprobs*** `number` Optional ## **user** `string` Optional **response\_format** `object` Optional Specifies the format of the model's output. Use this to request structured responses.
Show response\_format structure **type** `string` Required The type of response format. *Allowed values: `"text"`, `"json_object"`, `"json_schema"`* * `"text"` - Standard text response (default) * `"json_object"` - Response will be valid JSON * `"json_schema"` - Response will conform to a specified JSON schema **json\_schema** `object` Conditional Schema definition (required when type is `"json_schema"`) *Contains:* * **name** `string` Required The name of the schema * **strict** `boolean` Optional Whether to enforce strict schema adherence. Default: `false` * **schema** `object` Required JSON Schema definition with: * **type** `string` - Schema type (e.g., `"object"`) * **properties** `object` - Property definitions * **required** `array` - Required property names * **additionalProperties** `boolean` - Allow extra properties
*** **tools** `array` Optional
A list of tools the model may call
Show tool structure Each tool object contains: **type** `string` Required\ *Must be: `"function"`* **function** `object` Required\ The function definition **function.name** `string` Required\ The name of the function **function.parameters** `object` Required\ The parameters the function accepts
*** **tool\_choice** `string` or `object` Optional
Controls which tool is called
*Allowed string values: `"none"`, `"auto"`*
*Or specify a tool with:* ```json theme={null} { "type": "function", "function": { "name": "tool_name" } } ``` *** * **Sample Request** 1. **Type: Text**
Show sample ```json theme={null} { "messages": [ { "role": "user", "content": "Hello, can you help me with my research?" } ], "tools": [ { "type": "function", "function": { "name": "get_weather", "description": "Get current temperature of given location", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "City and country (e.g. Paris, France)" } }, "required": ["location"], "additionalProperties": false }, "strict": true } } ] }; ```
2. **Type: Image (in URL)**
Show sample ```json theme={null} { "messages": [ { "role": "user", "content": [ { "type": "text", "text": "Hello, can you help me with my research?" }, { "type": "image_url", "image_url": { "url": "https://test.png" } }, ] } ], "tools": [] }; ```
3. **Type: Image (in Base64)**
Show sample ```json theme={null} { "messages": [ { "role": "user", "content": [ { "type": "text", "text": "Hello, can you help me with my research?" }, { "type": "image_url", "image_url": { "url": "data:image/png;base64,iV..." } }, ] } ], "tools": [] }; ```
4. **Type: Docs (PDF)**
Show sample ```json theme={null} { "messages": [ { "role": "user", "content": [ { "type": "text", "text": "Hello, what's inside the PDF?" }, { "type": "file", "file": { "filename": "Sample File Name", "file_data": "data:application/pdf;base64,JVBERi0xLjMNCiXi48/....", } } ] } ], "tools": [] }; ```
5. **Type: Docs** * Supported File Types: - `json`, `xlsx`, `xlsm`, `csv`, `md`, `pptx`, `docx`, `txt`
Show sample ```json theme={null} { "messages": [ { "role": "user", "content": [ { "type": "text", "text": "Hello, what's inside the PDF?" }, { "type": "input_file", "file_url": "https://file_url", } ] } ], "tools": [] }; ```
6. **Type: JSON Schema Response**
Show sample ```json theme={null} { "model": "google/gemini-2.5-flash", "messages": [ { "role": "user", "content": "Tell me about a cat named Whiskers. Return the response as a JSON object with the following fields: 'name' (string), 'color' (string - the cat's fur color), 'age' (integer - in years), and 'personality' (string - brief description). Make sure to include all required fields." } ], "response_format": { "type": "json_schema", "json_schema": { "name": "cat_info", "strict": true, "schema": { "type": "object", "properties": { "name": { "type": "string", "description": "The cat's name" }, "color": { "type": "string", "description": "The cat's fur color" }, "age": { "type": "integer", "description": "The cat's age in years" }, "personality": { "type": "string", "description": "Brief description of the cat's personality" } }, "required": ["name", "color", "age", "personality"], "additionalProperties": false } } } } ```
*** * **Response**: 1. **Without Tools**
Show sample ```json theme={null} { "choices": [ { "index": 0, "message": { "content": "Hello! How can I assist you today?", "role": "assistant" } } ] } ```
2. **With Tools**
Show sample ```json theme={null} { "choices": [ { "index": 0, "message": { "content": "", "role": "assistant", "tool_calls": [ { "id": "call_zSIBPi4QKxjkpAewfi5YbTnI", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\":\"Paris, France\"}" } } ] } } ] } ```
3. **With JSON Schema**
Show sample ```json theme={null} { "choices": [ { "index": 0, "message": { "content": "{\"name\":\"Whiskers\",\"color\":\"orange tabby\",\"age\":3,\"personality\":\"Playful and curious, loves to explore and cuddle\"}", "role": "assistant" } } ] } ```
*** * **Error** | Response Code | Reason | | - | - | | 400 | Validation Error | | 401 | Unauthorized | | 404 | Agent not found | This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.