Advanced Parameters

Chat Completions Parameters

These parameters are available on the Chat Completions endpoint (OpenAI-compatible).

Core Parameters

Parameter	Type	Required	Default	Description
`model`	string	Yes	—	Model ID to use. See List Models for available models.
`messages`	array	Yes	—	Array of message objects with `role` and `content`.
`max_tokens`	integer	No	1000	Maximum tokens to generate. Range: 1 to model’s max context.
`stream`	boolean	No	`false`	Enable Server-Sent Events streaming.

Sampling Parameters

Parameter	Type	Range	Default	Description
`temperature`	float	0–2	1.0	Controls randomness. Lower values (0.1–0.3) produce focused, deterministic output. Higher values (0.8–1.5) increase creativity and variety. Set to 0 for greedy decoding.
`top_p`	float	0–1	1.0	Nucleus sampling — only consider tokens with cumulative probability above this threshold. Lower values (0.1) make output more focused. Use either `temperature` or `top_p`, not both.
`top_k`	integer	1+	—	Only sample from the top K most likely tokens. Lower values constrain output. Not all models support this.

Avoid setting both temperature and top_p at the same time. Use one or the other for best results.

Penalty Parameters

Parameter	Type	Range	Default	Description
`presence_penalty`	float	-2 to 2	0	Penalizes tokens that have appeared in the text so far. Positive values encourage the model to explore new topics.
`frequency_penalty`	float	-2 to 2	0	Penalizes tokens based on how often they’ve appeared. Positive values reduce repetition proportionally to frequency.
`repetition_penalty`	float	0.1–2	1.0	Multiplicative penalty on repeated tokens. Values > 1 discourage repetition, < 1 encourage it.

Stop Sequences

Parameter	Type	Default	Description
`stop`	string or array	`null`	Up to 4 sequences where the API will stop generating. The stop sequence is not included in the output.

{
  "stop": ["\n\n", "END", "```"]
}

Response Format

Parameter	Type	Default	Description
`response_format`	object	—	Force the model to output in a specific format.
`seed`	integer	—	Attempt deterministic output. Same seed + same input should produce same output.
`n`	integer	1	Number of completions to generate.

JSON mode:

{
  "response_format": {"type": "json_object"}
}

When using JSON mode, you must also instruct the model to output JSON in your system or user message, e.g. “Respond in JSON format.”

Function Calling

Parameter	Type	Default	Description
`tools`	array	—	List of tools/functions the model can call. See Function Calling.
`tool_choice`	string or object	`"auto"`	Controls tool usage: `"auto"`, `"none"`, `"required"`, or a specific tool.
`parallel_tool_calls`	boolean	`true`	Whether the model can call multiple tools in one turn.

Messages Parameters

These parameters are available on the Messages endpoint (Anthropic-compatible).

Core Parameters

Parameter	Type	Required	Default	Description
`model`	string	Yes	—	Model ID to use.
`messages`	array	Yes	—	Input messages. Roles: `user` and `assistant` only (system goes in `system` param).
`max_tokens`	integer	Yes	—	Maximum tokens to generate. Required for Anthropic format.
`system`	string	No	—	System prompt. Passed separately, not as a message.
`stream`	boolean	No	`false`	Enable streaming via Server-Sent Events.

Sampling Parameters

Parameter	Type	Range	Default	Description
`temperature`	float	0–1	1.0	Controls randomness. Note: Anthropic format caps at 1.0, not 2.0.
`top_p`	float	0–1	—	Nucleus sampling threshold.
`top_k`	integer	1+	—	Only sample from the top K tokens.

Stop Sequences

Parameter	Type	Default	Description
`stop_sequences`	array	—	Custom stop sequences.

Tool Use

Parameter	Type	Default	Description
`tools`	array	—	Tools the model can use. Uses `input_schema` instead of `parameters`. See Function Calling.
`tool_choice`	object	`{"type": "auto"}`	Controls tool usage: `{"type": "auto"}`, `{"type": "any"}`, or `{"type": "tool", "name": "..."}`.

Common Patterns

Deterministic Output

For reproducible results, use low temperature with a seed:

{
  "temperature": 0,
  "seed": 42
}

Creative Writing

For creative, varied output:

{
  "temperature": 1.2,
  "presence_penalty": 0.6,
  "frequency_penalty": 0.3
}

Structured Extraction

For extracting structured data:

{
  "temperature": 0,
  "response_format": {"type": "json_object"},
  "max_tokens": 2000
}

Code Generation

For code generation tasks:

{
  "temperature": 0.2,
  "top_p": 0.95,
  "stop": ["\n\n\n", "```"]
}

Conversational

For natural, engaging conversations:

{
  "temperature": 0.8,
  "presence_penalty": 0.5,
  "max_tokens": 500
}

Using the APIs

Our AI APIs

Advanced Parameters

Chat Completions Parameters

Core Parameters

Sampling Parameters

Penalty Parameters

Stop Sequences

Response Format

Function Calling

Messages Parameters

Core Parameters

Sampling Parameters

Stop Sequences

Tool Use

Common Patterns

Deterministic Output

Creative Writing

Structured Extraction

Code Generation

Conversational

​Chat Completions Parameters

​Core Parameters

​Sampling Parameters

​Penalty Parameters

​Stop Sequences

​Response Format

​Function Calling

​Messages Parameters

​Core Parameters

​Sampling Parameters

​Stop Sequences

​Tool Use

​Common Patterns

​Deterministic Output

​Creative Writing

​Structured Extraction

​Code Generation

​Conversational

Chat Completions Parameters

Core Parameters

Sampling Parameters

Penalty Parameters

Stop Sequences

Response Format

Function Calling

Messages Parameters

Core Parameters

Sampling Parameters

Stop Sequences

Tool Use

Common Patterns

Deterministic Output

Creative Writing

Structured Extraction

Code Generation

Conversational