Reasoning Models

Some models think out loud before answering. They work through problems step by step, then give you a final answer. This makes them stronger at math, code, and logic-heavy tasks.

See the full list of models, pricing and context limits on the Models page. Not all reasoning models support the reasoning_effort parameter. See model support for details.

Reading the output

Reasoning models return their thinking in a separate reasoning_content field, keeping content clean:

response = client.chat.completions.create(
    model="zai-org-glm-5-1",
    messages=[{"role": "user", "content": "What is 15% of 240?"}]
)

thinking = response.choices[0].message.reasoning_content
answer = response.choices[0].message.content

const response = await client.chat.completions.create({
    model: "zai-org-glm-5-1",
    messages: [{ role: "user", content: "What is 15% of 240?" }]
});

const thinking = response.choices[0].message.reasoning_content;
const answer = response.choices[0].message.content;

curl https://api.venice.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "zai-org-glm-5-1",
    "messages": [{"role": "user", "content": "What is 15% of 240?"}]
  }'

Some providers (Anthropic, Google, OpenAI, Qwen) return encrypted or summarized reasoning tokens. When this happens, reasoning_content contains a "[Some reasoning content is encrypted]" placeholder.

Streaming

When streaming, reasoning_content arrives in the delta before the final answer:

stream = client.chat.completions.create(
    model="zai-org-glm-5-1",
    messages=[{"role": "user", "content": "Explain photosynthesis"}],
    stream=True
)

for chunk in stream:
    if chunk.choices:
        delta = chunk.choices[0].delta
        if delta.reasoning_content:
            print(delta.reasoning_content, end="")
        if delta.content:
            print(delta.content, end="")

const stream = await client.chat.completions.create({
    model: "zai-org-glm-5-1",
    messages: [{ role: "user", content: "Explain photosynthesis" }],
    stream: true
});

for await (const chunk of stream) {
    if (chunk.choices?.[0]?.delta) {
        const delta = chunk.choices[0].delta;
        if (delta.reasoning_content) process.stdout.write(delta.reasoning_content);
        if (delta.content) process.stdout.write(delta.content);
    }
}

curl https://api.venice.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "zai-org-glm-5-1",
    "messages": [{"role": "user", "content": "Explain photosynthesis"}],
    "stream": true
  }'

Reasoning effort

The reasoning_effort parameter controls how much thinking a model does before responding. Higher effort means deeper reasoning but more tokens and latency.

Accepted values

Value	Description
`none`	Disables reasoning entirely
`minimal`	Basic reasoning with minimal effort
`low`	Light reasoning for simple problems
`medium`	Balanced reasoning for moderate complexity
`high`	Deep reasoning for complex problems
`xhigh`	Extra-high reasoning depth
`max`	Maximum reasoning capability

Not all models support all values. Venice does not auto-map to the nearest supported level. Unsupported values return a 400 error from the upstream provider. For example, sending xhigh to Claude or max to GPT-5.2 will fail.When in doubt, use low, medium, or high. These are the most widely supported values.

Model support

The tables below list models with known reasoning_effort support. Other models may still generate reasoning tokens (visible in usage.completion_tokens_details.reasoning_tokens) without exposing an effort control. To check whether a specific model supports reasoning or the reasoning_effort parameter, read the supportsReasoning and supportsReasoningEffort fields on the /v1/models endpoint.

OpenAI

Model	Supported values
GPT-5.2	`none`, `low`, `medium`, `high`, `xhigh`
GPT-5.2 Codex, GPT-5.3 Codex	`low`, `medium`, `high`, `xhigh`

Anthropic

Model	Supported values
Claude Opus 4.6, Opus 4.6 Fast	`low`, `medium`, `high`, `max`
Claude Opus 4.5, Sonnet 4.5, Sonnet 4.6	`low`, `medium`, `high`

Google

Model	Supported values
Gemini 3 Pro Preview	`low`, `high`
Gemini 3.1 Pro Preview	`low`, `medium`, `high`
Gemini 3 Flash Preview	`minimal`, `low`, `medium`, `high`

xAI

Grok models (Grok 4.1 Fast, Grok Code Fast) do not support reasoning_effort. Specifying it will result in an error.

Other models

Model	Supported values
Qwen 3 235B A22B Thinking, Qwen 3.5 35B A3B	`low`, `medium`, `high`
Kimi K2.5	`low`, `medium`, `high`
MiniMax M2.5, M2.1	`low`, `medium`, `high`
GLM 5.1 series	Built-in reasoning only, not configurable
DeepSeek R1	Built-in reasoning only, not configurable

Usage

Pass reasoning_effort as a top-level parameter or use the nested reasoning.effort format:

response = client.chat.completions.create(
    model="minimax-m25",
    messages=[{"role": "user", "content": "Prove that there are infinitely many primes"}],
    extra_body={"reasoning": {"effort": "high"}}
)

const response = await client.chat.completions.create({
    model: "minimax-m25",
    messages: [{ role: "user", content: "Prove that there are infinitely many primes" }],
    reasoning: { effort: "high" }
});

curl https://api.venice.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "minimax-m25",
    "messages": [{"role": "user", "content": "Prove that there are infinitely many primes"}],
    "reasoning": {"effort": "high"}
  }'

The flat format "reasoning_effort": "high" is also accepted.

Disabling reasoning

There are two ways to disable reasoning:

Method	Syntax	How it works
`reasoning.enabled: false`	`"reasoning": {"enabled": false}`	Venice-level toggle that prevents reasoning parameters from being sent to the provider. Recommended.
`reasoning.effort: "none"`	`"reasoning": {"effort": "none"}`	Passed to the provider, which decides how to handle it. Only supported by some models (e.g. GPT-5.x).

For models that support it, reasoning.enabled: false is the more reliable option:

Model	Can disable?
GPT-5.2	Yes
GPT-5.2 Codex, GPT-5.3 Codex	Yes (but `none` effort not supported)
Qwen 3 235B A22B Thinking, Qwen 3.5 35B A3B	Yes
GLM 5.1 series	Yes
Claude Opus 4.5/4.6/4.6 Fast, Sonnet 4.5/4.6	No (always reasons)
Gemini 3 Pro, 3.1 Pro, 3 Flash	No (always reasons)
DeepSeek R1	No (always reasons)

response = client.chat.completions.create(
    model="openai-gpt-52",
    messages=[{"role": "user", "content": "What's the capital of France?"}],
    extra_body={"reasoning": {"enabled": False}}
)

const response = await client.chat.completions.create({
    model: "openai-gpt-52",
    messages: [{ role: "user", content: "What's the capital of France?" }],
    reasoning: { enabled: false }
});

curl https://api.venice.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $VENICE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai-gpt-52",
    "messages": [{"role": "user", "content": "What is the capital of France?"}],
    "reasoning": {"enabled": false}
  }'

Token limits

Reasoning models generate visible answer tokens (in content) and reasoning tokens (in reasoning_content). Both count toward your token budget.

Setting a token cap

Use max_completion_tokens to cap the total number of tokens the model generates, including reasoning:

{
  "model": "deepseek-v4-flash",
  "messages": [...],
  "max_completion_tokens": 500
}

max_tokens is also accepted and behaves the same way. If both are set, max_completion_tokens takes precedence. To get more visible output, raise the cap, lower reasoning_effort, or disable reasoning.

Reading the breakdown

The usage object shows how your budget was spent:

"usage": {
  "completion_tokens": 501,
  "completion_tokens_details": { "reasoning_tokens": 169 },
  "prompt_tokens": 13,
  "total_tokens": 514
}

In this example, 169 tokens were spent on reasoning and 332 on the visible answer. When the cap is reached, finish_reason is length. Each model’s upper bound is available as maxCompletionTokens on the /v1/models endpoint.

Non-reasoning models

max_tokens and max_completion_tokens behave the same on non-reasoning models, capping visible output directly.

Capability discovery

Check what a model supports via the /v1/models endpoint:

Field	Meaning
`supportsReasoning`	Model has reasoning capability (chain-of-thought)
`supportsReasoningEffort`	Model accepts the `reasoning_effort` / `reasoning.effort` parameter

Best practices

Default to medium for general use
Use high or xhigh for complex tasks (math, code, analysis)
Use low for latency-sensitive applications
Use reasoning.enabled: false or set effort to none to disable reasoning
When in doubt, use low, medium, or high. These are the most widely supported values

Docs

Getting Started

Text & Chat

Image, Video & Audio

Search & RAG

Agents & Integrations

Coding Tools

Agent Tooling

SDKs & Frameworks

Reading the output

Streaming

Reasoning effort

Accepted values

Model support

OpenAI

Anthropic

Google

xAI

Other models

Usage

Disabling reasoning

Token limits

Setting a token cap

Reading the breakdown

Non-reasoning models

Capability discovery

Best practices

​Reading the output

​Streaming

​Reasoning effort

​Accepted values

​Model support

​OpenAI

​Anthropic

​Google

​xAI

​Other models

​Usage

​Disabling reasoning

​Token limits

​Setting a token cap

​Reading the breakdown

​Non-reasoning models

​Capability discovery

​Best practices

Reading the output

Streaming

Reasoning effort

Accepted values

Model support

OpenAI

Anthropic

Google

xAI

Other models

Usage

Disabling reasoning

Token limits

Setting a token cap

Reading the breakdown

Non-reasoning models

Capability discovery

Best practices