> For clean Markdown of any page, append `.md` to the page URL.
> For a complete documentation index, see https://docs.sarvam.ai/llms.txt.
> For full documentation content in one file, see https://docs.sarvam.ai/llms-full.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.sarvam.ai/_mcp/server.

# Chat Completion V2

POST https://api.sarvam.ai/v2/chat/completions
Content-Type: application/json

Creates a model response for the given chat conversation, using an OpenAI-compatible request and response shape.

Requires `api-subscription-key` with beta access to this endpoint.

**Streaming is optional.** Default is one JSON response (`stream` omitted or `false`). Set `stream: true` for server-sent events; the stream ends with a `[DONE]` line.

**Reasoning (`glm5.3`, `deepseekv4-flash`):** set `reasoning_effort` to **`low`**, **`high`**, or **`max`**. Default when omitted is **`max`** — omit the field or pass **`max`** for maximum reasoning. The trace is in `choices[].message.reasoning_content` and counts toward `max_tokens`. `gemma4` does not use reasoning on this route.

Request fields documented on this operation are validated by the API. Other OpenAI-compatible fields may be forwarded to the model when sent.

Legacy `functions` / `function_call` are rejected — use `tools` and `tool_choice`.

Reference: https://docs.sarvam.ai/api-reference/chat/chat-completions-v2

## Authentication

- `api-subscription-key` header (required) — API Key authentication via header
- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Request

### Body (application/json)

This endpoint expects an object.

- `messages` (list of object or object or object or object or object or object, required) — Non-empty conversation history. Roles: `system`, `developer`, `user`, `assistant`, `tool`. Content is a string or an array of parts (`text`, `image_url`). Images must use inline `data:image/…;base64,…` URLs — remote HTTP(S) image URLs are rejected.
  - ChatCompletionRequestSystemMessage
    - `content` (string, required) — The contents of the system message.
    - `role` ("system", required) — The role of the messages author, in this case `system`.
  - ChatCompletionRequestDeveloperMessage
    - `content` (string, required) — The contents of the developer message.
    - `role` ("developer", required) — The role of the messages author, in this case `developer`.
  - ChatCompletionRequestUserMessage
    - `role` ("user", required) — The role of the messages author, in this case `user`.
    - `content` (string or list of object, required) — The contents of the user message.
  - ChatCompletionRequestAssistantMessage
    - `role` ("assistant", required) — The role of the messages author, in this case `assistant`.
    - `content` (string, optional, nullable) — The contents of the assistant message
    - `tool_calls` (list of object, optional, nullable) — The tool calls generated by the model.
      - `id` (string, required) — Tool call id (for example `call-<uuid>`).
      - `type` ("function", required) — The type of the tool call, currently only `function`.
      - `function` (object, required)
        - `name` (string, required) — The name of the function to call.
        - `arguments` (string, required) — The arguments to call the function with, as a JSON string.
  - ChatCompletionRequestToolMessage
    - `role` ("tool", required) — The role of the messages author, in this case `tool`.
    - `content` (string, required) — The contents of the tool message.
    - `tool_call_id` (string, required) — Tool call that this message is responding to.
  - ChatCompletionRequestGenericMessage
    - `role` (string, required) — The role of the messages author.
    - `content` (string or list of object, required) — The contents of the message.
    - `name` (string, optional, nullable) — An optional name for the participant.
- `model` (enum, required) — Model IDs accepted by `POST /v2/chat/completions` (case-sensitive; unknown ids return `404`): - **`sarvam-105b`** — Sarvam flagship chat model. - **`glm5.3`** — 1,048,576-token context window; visible reasoning in `reasoning_content` (billed as completion tokens); tool calling; max request size 10,485,760 bytes; `n` must be `1`. - **`gemma4`** — image input (inline base64) and tool calling. - **`deepseekv4-flash`** — 1,048,576-token context window, tool calling, and reasoning.
  - Allowed values: `sarvam-105b`, `glm5.3`, `gemma4`, `deepseekv4-flash`
- `temperature` (double, optional, nullable, default: 1) — Sampling temperature from `0` to `2`. Higher values increase variation; lower values focus the output. Output is not guaranteed to be identical across requests, even at `0`. Prefer changing either `temperature` or `top_p`, not both.
- `top_p` (double, optional, nullable, default: 0.95) — Nucleus sampling: greater than `0` and at most `1`. On `glm5.3`, `top_p: 0` is rejected. Prefer changing either `top_p` or `temperature`, not both.
- `reasoning_effort` (enum, optional, nullable) — On reasoning models (`glm5.3`, `deepseekv4-flash`): **`low`**, **`high`**, or **`max`**. Default when omitted is **`max`** — omit this field or set **`max`** for maximum reasoning. Trace in `message.reasoning_content`; billed as completion tokens and counts toward `max_tokens`. Ignored on non-reasoning models such as `gemma4`.
  - Allowed values: `low`, `high`, `max`
- `max_tokens` (integer, optional, nullable, default: 2048) — Maximum tokens to generate in the completion, including reasoning tokens on reasoning models. Default `2048`. Set explicitly when you need longer answers — a low limit can yield `finish_reason: "length"` with little or no visible `content` if reasoning consumes the budget.
- `stream` (boolean, optional, nullable, default: false) — Optional. Default `false` — omit or `false` for one JSON response. If `true`, the response is streamed as server-sent events and ends with a `[DONE]` line. Use `stream_options.include_usage: true` to receive a final usage chunk (including `reasoning_tokens`). That chunk has an empty `choices` array — do not assume `choices[0]` is present on every event.
- `stop` (string or list of string, optional, nullable) — Up to 4 stop sequences (string or array). Generated text excludes the matched sequence. On `glm5.3`, more than four entries may return `503 model_overloaded` rather than `400`.
- `n` (integer, optional, nullable, default: 1) — Number of chat completion choices to generate per request. You are billed for tokens across all choices. Default `1`. On `glm5.3`, only `n: 1` is accepted; higher values return `400 invalid_request_error`.
- `seed` (integer, optional, nullable) — Optional integer seed for OpenAI SDK compatibility.
- `frequency_penalty` (double, optional, nullable, default: 0) — Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model's likelihood to repeat the same line verbatim.
- `presence_penalty` (double, optional, nullable, default: 0) — Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far, increasing the model's likelihood to talk about new topics.
- `tools` (list of object, optional, nullable) — A list of tools the model may call. Currently, only functions are supported as a tool.
  - `type` ("function", required) — The type of the tool. Currently, only `function` is supported.
  - `function` (object, required)
    - `name` (string, required) — The name of the function to be called.
    - `description` (string, optional, nullable) — A description of what the function does.
    - `parameters` (map from string to any, optional, nullable) — The parameters the function accepts, described as a JSON Schema object.
- `tool_choice` (enum or object, optional, nullable) — Controls tool calling: `auto`, `none`, `required`, or a named function object. `required` with an empty `tools` array returns `400`. A named function that is not listed in `tools` returns `400`.
  - ChatCompletionNamedToolChoice
    - `type` ("function", required) — The type of the tool. Currently, only `function` is supported.
    - `function` (object, required)
      - `name` (string, required) — The name of the function to call.
- `response_format` (object, optional, nullable) — An object specifying the format that the model must output. Setting `{ "type": "json_schema", "json_schema": {...} }` enables Structured Outputs which guarantees the model generates output matching the supplied JSON Schema. Setting `{ "type": "json_object" }` enables the older JSON mode, which guarantees valid JSON but not a specific schema.
  - `type`: `json_object` (ResponseFormatJsonObject)
  - `type`: `json_schema` (ResponseFormatJsonSchema)
    - `json_schema` (object, required) — Structured Outputs configuration options, including a JSON Schema.
      - `name` (string, required) — The name of the response format. Must contain only alphanumeric characters, underscores and dashes.
      - `schema` (map from string to any, required) — The schema for the response format, described as a JSON Schema object.
      - `description` (string, optional, nullable) — A description of what the response format is for, used by the model to determine how to respond in the format.
      - `strict` (boolean, optional, nullable, default: false) — Whether to enable strict schema adherence when generating the output.
  - `type`: `text` (ResponseFormatText)
- `extra_body` (map from string to any, optional, default: {}) — Additional model-specific options merged into the request. Must not duplicate a top-level field documented on this endpoint; duplicates return `400 invalid_request_error`.
- `top_k` (integer, optional, nullable) — Top-k sampling. Omit or set to `-1` to disable. Values `>= 1` enable top-k; `0` is rejected. There is no documented upper bound.
- `min_p` (double, optional, nullable) — Minimum probability mass. Must be between 0 and 1 inclusive. Outside that range is `400`.
- `repetition_penalty` (double, optional, nullable) — Repetition penalty. Must be greater than 0 and at most 2. `0` and values above 2 are `400`.
- `parallel_tool_calls` (boolean, optional, nullable) — **`false`** is correctly enforced (a single tool call) on **`gemma4`** and **`deepseekv4-flash`**. On **`glm5.3`** and **`sarvam-105b`**, **`false`** is accepted without error but is **not** enforced — the model may still return multiple tool calls in one turn.
- `stream_options` (object, optional, nullable) — Only valid with `stream: true` (otherwise `400`). Must be a top-level field, not inside `extra_body`. Use `{"include_usage": true}` to receive token usage in the final SSE chunk.
  - `include_usage` (boolean, optional) — If `true`, a final SSE chunk includes `usage`, with `completion_tokens_details.reasoning_tokens` when applicable. That chunk has an empty `choices` array.
- `logprobs` (boolean, optional, nullable) — If `true`, return log probabilities for output tokens (use with `top_logprobs`). Supported on **`sarvam-105b`** and **`gemma4`**. Not supported on **`glm5.3`** (`400` if enabled) or **`deepseekv4-flash`** (returns `503 model_overloaded` instead of a clean rejection — omit this field for that model).
- `top_logprobs` (integer, optional, nullable) — How many top token log probabilities to return at each position when `logprobs` is `true` (otherwise **`400`**). Same model support as `logprobs`: works on `sarvam-105b` and `gemma4`; on `glm5.3` and `deepseekv4-flash`, omit entirely — do not send `0`, since many SDKs add it by default.

## Response

### 200

Successful Response

- `id` (string, required) — A unique identifier for the chat completion.
- `choices` (list of object, required) — A list of chat completion choices. Can be more than one if `n` is greater than 1.
  - `finish_reason` (enum, required) — The reason the model stopped generating tokens. This will be `stop` if the model hit a natural stop point or a provided stop sequence, `length` if the maximum number of tokens specified in the request was reached, `content_filter` if content was omitted due to a flag from our content filters, `tool_calls` if the model called a tool, or `function_call` (deprecated) if the model called a function.
    - Allowed values: `stop`, `length`, `tool_calls`, `content_filter`, `function_call`
  - `index` (integer, required) — The index of the choice in the list of choices.
  - `message` (object, required)
    - `content` (string, required, nullable) — Assistant message text. May be `null` when `tool_calls` is present.
    - `role` (enum, required) — The role of the author of this message.
      - Allowed values: `assistant`
    - `refusal` (string, optional, nullable)
    - `reasoning_content` (string, optional, nullable) — Visible reasoning trace from the model, when supported. Billed as completion tokens.
    - `tool_calls` (list of object, optional, nullable) — The tool calls generated by the model.
      - `id` (string, required) — Tool call id (for example `call-<uuid>`).
      - `type` ("function", required) — The type of the tool call, currently only `function`.
      - `function` (object, required)
        - `name` (string, required) — The name of the function to call.
        - `arguments` (string, required) — The arguments to call the function with, as a JSON string.
  - `logprobs` (map from string to any, optional, nullable) — Token log probabilities when supported (`sarvam-105b`, `gemma4`). Always `null` on `glm5.3` and `deepseekv4-flash`, which don't support this field.
- `created` (integer, required) — The Unix timestamp (in seconds) of when the chat completion was created.
- `model` (string, required) — The model used for the chat completion.
- `object` ("chat.completion", required) — The object type, which is always `chat.completion`.
- `service_tier` (string, optional, nullable)
- `system_fingerprint` (string, optional, nullable) — OpenAI-compatible backend fingerprint when available. Always `null` on `glm5.3`.
- `usage` (object, optional, nullable)
  - `completion_tokens` (integer, required) — Number of tokens in the generated completion.
  - `prompt_tokens` (integer, required) — Number of tokens in the prompt.
  - `total_tokens` (integer, required) — Total number of tokens used in the request (prompt + completion).
  - `completion_tokens_details` (object, optional, nullable)
    - `reasoning_tokens` (integer, optional, nullable) — Tokens spent on the chain-of-thought. Billed as completion / output tokens.
  - `prompt_tokens_details` (object, optional, nullable) — `null` on a cache miss. On a hit, includes `cached_tokens`. Treat a missing object and `cached_tokens: 0` as different when computing cache-hit rates.
    - `cached_tokens` (integer, optional) — Prompt tokens served from cache and billed at the cached-input rate.

## Errors

### 400 Bad Request Error

Invalid request — wrong types or shapes in the JSON body (the gateway may return a serde-style message such as a field that expected a boolean receiving a string), unsupported parameters, model capability mismatch (e.g. image to a text-only model, remote image URL), or the context-window guard (prompt plus requested completion budget exceeds the model limit). The response includes `error.message` and, when present, `error.request_id` for support.

- `any`

### 401 Unauthorized Error

Missing or invalid API key — returned as 403 invalid_api_key_error in practice.

- `any`

### 403 Forbidden Error

Missing or invalid API key (`invalid_api_key_error`).

- `any`

### 404 Not Found Error

Unknown or wrongly cased model id (`not_found_error`). Model ids are case-sensitive.

- `any`

### 413 Content Too Large Error

Serialised request body larger than 10,485,760 bytes (10 MB), including text and inline image data.

- `any`

### 429 Too Many Requests Error

Rate limit exceeded, or account seat budget exhausted.

- `any`

### 502 Bad Gateway Error

The model backend could not be reached (`model_call_failed`). Retry the request.

- `any`

### 503 Service Unavailable Error

Model overloaded (`model_overloaded`). Retry with backoff. On `glm5.3`, more than four `stop` sequences may return `503` rather than `400` — client retry logic may treat that as transient overload.

- `any`

## Examples

**Request**

```json
{
  "messages": [
    {
      "content": "Summarise the causes of the 2008 financial crisis.",
      "role": "user"
    }
  ],
  "model": "glm5.3"
}
```

**Response**

```json
{
  "id": "20250101_0a1b2c3d-1234-5678-9abc-def012345678",
  "choices": [
    {
      "finish_reason": "stop",
      "index": 0,
      "message": {
        "content": "The 2008 financial crisis was driven by a housing bubble, subprime lending, and the collapse of mortgage-backed securities.",
        "role": "assistant",
        "refusal": null,
        "reasoning_content": null,
        "tool_calls": null
      },
      "logprobs": {}
    }
  ],
  "created": 1735689600,
  "model": "glm5.3",
  "object": "chat.completion",
  "system_fingerprint": null,
  "usage": {
    "completion_tokens": 24,
    "prompt_tokens": 18,
    "total_tokens": 42,
    "completion_tokens_details": {
      "reasoning_tokens": 10
    },
    "prompt_tokens_details": {
      "cached_tokens": 0
    }
  }
}
```

**SDK Code**

```typescript chat_completionsV2_example
import { SarvamAIClient } from "sarvamai";

async function main() {
    const client = new SarvamAIClient({
        apiSubscriptionKey: "YOUR_API_KEY_HERE",
    });
    await client.chat.completionsV2({
        messages: [
            {
                content: "Summarise the causes of the 2008 financial crisis.",
                role: "user",
            },
        ],
        model: "glm5.3",
    });
}
main();

```

```python chat_completionsV2_example
from sarvamai import SarvamAI

client = SarvamAI(
    api_subscription_key="YOUR_API_KEY_HERE",
)

client.chat.completions_v2(
    messages=[
        {
            "content": "Summarise the causes of the 2008 financial crisis.",
            "role": "user"
        }
    ],
    model="glm5.3",
)

```

```go chat_completionsV2_example
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.sarvam.ai/v2/chat/completions"

	payload := strings.NewReader("{\n  \"messages\": [\n    {\n      \"content\": \"Summarise the causes of the 2008 financial crisis.\",\n      \"role\": \"user\"\n    }\n  ],\n  \"model\": \"glm5.3\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("api-subscription-key", "<apiSubscriptionKey>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby chat_completionsV2_example
require 'uri'
require 'net/http'

url = URI("https://api.sarvam.ai/v2/chat/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["api-subscription-key"] = '<apiSubscriptionKey>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"messages\": [\n    {\n      \"content\": \"Summarise the causes of the 2008 financial crisis.\",\n      \"role\": \"user\"\n    }\n  ],\n  \"model\": \"glm5.3\"\n}"

response = http.request(request)
puts response.read_body
```

```java chat_completionsV2_example
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.sarvam.ai/v2/chat/completions")
  .header("api-subscription-key", "<apiSubscriptionKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"messages\": [\n    {\n      \"content\": \"Summarise the causes of the 2008 financial crisis.\",\n      \"role\": \"user\"\n    }\n  ],\n  \"model\": \"glm5.3\"\n}")
  .asString();
```

```php chat_completionsV2_example
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.sarvam.ai/v2/chat/completions', [
  'body' => '{
  "messages": [
    {
      "content": "Summarise the causes of the 2008 financial crisis.",
      "role": "user"
    }
  ],
  "model": "glm5.3"
}',
  'headers' => [
    'Content-Type' => 'application/json',
    'api-subscription-key' => '<apiSubscriptionKey>',
  ],
]);

echo $response->getBody();
```

```csharp chat_completionsV2_example
using RestSharp;

var client = new RestClient("https://api.sarvam.ai/v2/chat/completions");
var request = new RestRequest(Method.POST);
request.AddHeader("api-subscription-key", "<apiSubscriptionKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"messages\": [\n    {\n      \"content\": \"Summarise the causes of the 2008 financial crisis.\",\n      \"role\": \"user\"\n    }\n  ],\n  \"model\": \"glm5.3\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift chat_completionsV2_example
import Foundation

let headers = [
  "api-subscription-key": "<apiSubscriptionKey>",
  "Content-Type": "application/json"
]
let parameters = [
  "messages": [
    [
      "content": "Summarise the causes of the 2008 financial crisis.",
      "role": "user"
    ]
  ],
  "model": "glm5.3"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.sarvam.ai/v2/chat/completions")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```