Create Chat Completion

Send a conversation to any Gateway model using the OpenAI Chat Completions schema. Set stream: true to receive server-sent events; add stream_options: {"include_usage": true} to get token usage in the final chunk.

POST /router/v1/chat/completions

Create Chat Completion

cURL

curl --request POST \
  --url https://api.perplexity.ai/router/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "messages": [
    {
      "content": "<string>",
      "role": "developer",
      "name": "<string>"
    }
  ],
  "model": "gpt-5.4",
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "<string>",
        "parameters": {},
        "strict": false
      }
    }
  ]
}
'

200

{
  "id": "<string>",
  "choices": [
    {
      "index": 123,
      "message": {
        "content": "<string>",
        "refusal": "<string>",
        "role": "assistant",
        "tool_calls": [
          {
            "id": "<string>",
            "type": "function",
            "function": {
              "name": "<string>",
              "arguments": "<string>"
            }
          }
        ],
        "annotations": [
          {
            "type": "url_citation",
            "url_citation": {
              "end_index": 123,
              "start_index": 123,
              "url": "<string>",
              "title": "<string>"
            }
          }
        ],
        "function_call": {
          "arguments": "<string>",
          "name": "<string>"
        },
        "audio": {
          "id": "<string>",
          "expires_at": 123,
          "data": "<string>",
          "transcript": "<string>"
        }
      },
      "logprobs": {
        "content": [
          {
            "token": "<string>",
            "logprob": 123,
            "bytes": [
              123
            ],
            "top_logprobs": [
              {
                "token": "<string>",
                "logprob": 123,
                "bytes": [
                  123
                ]
              }
            ]
          }
        ],
        "refusal": [
          {
            "token": "<string>",
            "logprob": 123,
            "bytes": [
              123
            ],
            "top_logprobs": [
              {
                "token": "<string>",
                "logprob": 123,
                "bytes": [
                  123
                ]
              }
            ]
          }
        ]
      }
    }
  ],
  "created": 123,
  "model": "<string>",
  "object": "chat.completion",
  "service_tier": "auto",
  "system_fingerprint": "<string>",
  "usage": {
    "completion_tokens": 0,
    "prompt_tokens": 0,
    "total_tokens": 0,
    "completion_tokens_details": {
      "accepted_prediction_tokens": 0,
      "audio_tokens": 0,
      "reasoning_tokens": 0,
      "rejected_prediction_tokens": 0
    },
    "prompt_tokens_details": {
      "audio_tokens": 0,
      "cached_tokens": 0,
      "cache_write_tokens": 0
    }
  },
  "moderation": {
    "input": {
      "type": "moderation_results",
      "model": "<string>",
      "results": [
        {
          "type": "moderation_result",
          "model": "<string>",
          "flagged": true,
          "categories": {},
          "category_scores": {},
          "category_applied_input_types": {}
        }
      ]
    },
    "output": {
      "type": "moderation_results",
      "model": "<string>",
      "results": [
        {
          "type": "moderation_result",
          "model": "<string>",
          "flagged": true,
          "categories": {},
          "category_scores": {},
          "category_applied_input_types": {}
        }
      ]
    }
  }
}

The Gateway API accepts the OpenAI Chat Completions schema, with a defined subset of parameters. Requests using an unsupported parameter fail with a 400 naming the parameter.

Parameter support

Honored: model, messages, stream, stream_options.include_usage, max_completion_tokens, max_tokens, temperature, top_p, stop, reasoning_effort, service_tier (auto, default, flex, priority), response_format (text, json_schema), tools, tool_choice, parallel_tool_calls, prompt_cache_key.

Accepted but not forwarded to the model: user, safety_identifier, metadata.

Accepted only at their default values: n (1), logprobs (false), store (false), presence_penalty (0), frequency_penalty (0).

Rejected with a 400: seed, logit_bias, top_logprobs, functions (use tools), function_call (use tool_choice), modalities, audio, prediction, web_search_options, moderation, verbosity, prompt_cache_options, prompt_cache_retention, stream_options.include_obfuscation set to true, plus any unrecognized top-level field.

Notes: response_format.json_schema always runs in strict mode; json_object is not supported — use json_schema. Function tools require a description.

Errors

Errors use the OpenAI envelope:

{
  "error": {
    "code": null,
    "message": "Invalid model 'example/does-not-exist'. Permitted models can be found in the documentation at https://docs.perplexity.ai/docs/getting-started/models.",
    "param": null,
    "type": "invalid_request_error"
  }
}

type is invalid_request_error for 4xx errors, rate_limit_error for 429 (rate limited or model overloaded — retry after the Retry-After interval), and server_error for 5xx. Requests that fail before producing output are not billed.

Authorizations

Authorization · string · header · required

Your Perplexity API key.

Body

application/json

messages · (Developer message · object | System message · object | User message · object | Assistant message · object | Tool message · object | Function message · object)[] · required

The conversation so far, as an array of message objects with role and content. The leading system or developer message is applied as the system prompt.

Minimum array length: 1

Developer message

System message

User message

Assistant message

Tool message

Function message

Show child attributes

model · string enum<string> · required

The model that will process the request, as a creator/model-name id from the catalog — for example anthropic/claude-sonnet-5. Any cataloged model works with this endpoint.

Example:

"gpt-5.4"

metadata · object | null

Accepted for SDK compatibility; not forwarded to the model.

Show child attributes

temperature · number | null · default: 1

Sampling temperature, 0 to 2. Higher values produce more varied output. Adjust this or top_p, not both.

Required range: 0 <= x <= 2

Example:

1

top_p · number | null · default: 1

Nucleus-sampling threshold, 0 to 1. Adjust this or temperature, not both.

Required range: 0 <= x <= 1

Example:

1

user · string · deprecated

Accepted for SDK compatibility; not forwarded to the model.

Example:

"user-1234"

safety_identifier · string | null

Accepted for SDK compatibility; not forwarded to the model.

Maximum string length: 64

Example:

"safety-identifier-1234"

prompt_cache_key · string | null

Stable key grouping related requests to improve prompt-cache hit rates.

Example:

"prompt-cache-key-1234"

service_tier · enum<string> | null · default: auto

Processing tier for the request. flex halves token rates on supported models; auto and default are equivalent.

Available options: auto, default, flex, scale, priority

reasoning_effort · enum<string> | null · default: medium

How much reasoning the model performs before answering, on models that support it.

Available options: none, minimal, low, medium, high, xhigh, max

max_completion_tokens · integer | null

Upper bound on generated tokens for this request, including reasoning tokens.

response_format · Text · object

Output format. Use type json_schema for structured output; schemas always run in strict mode.

Text

JSON schema

JSON object

Show child attributes

stream · boolean | null · default: false

When true, tokens are sent as server-sent events as they are generated, terminated by data: [DONE].

stop · string string[] · default: <|endoftext|>

Up to 4 sequences at which generation stops.

Example:

"\n"

max_tokens · integer | null · deprecated

Legacy alias of max_completion_tokens.

stream_options · object | null

Streaming options. Only allowed when stream is true.

Show child attributes

tools · (Function tool · object | Custom tool · object)[]

Function tools the model may call. Every tool requires a description.

Function tool

Custom tool

Show child attributes

tool_choice · enum<string> Allowed tools · object Function tool choice · object Custom tool choice · object

Controls whether the model may call a tool, and which one.

Available options: none, auto, required

parallel_tool_calls · boolean · default: true

Whether the model may request more than one tool call in a single turn.

Response

200

application/json

Successful response. JSON for non-streaming requests; a text/event-stream of chat completion chunks terminated by data: [DONE] when stream is true.

id · string · required

Unique identifier for the completion.

choices · object[] · required

The completion. Contains exactly one choice.

Show child attributes

created · integer<unixtime> · required

Unix timestamp of when the completion was created.

model · string · required

The model id you requested. Billing always uses this model's published rates.

object · enum<string> · required

Always "chat.completion".

Available options: chat.completion

service_tier · enum<string> | null · default: auto

The processing tier that served the request.

Available options: auto, default, flex, scale, priority

system_fingerprint · string · deprecated

usage · object

Token accounting for the request.

Show child attributes

moderation · object

Show child attributes