modelparams.dev
API MCP GitHub

Providers

Alibaba Anthropic Bedrock Cerebras Cohere DeepSeek Fireworks Google Groq Meta MiniMax Mistral Moonshot AI NVIDIA OpenAI Perplexity Thinking Machines Vertex xAI Xiaomi Z.ai

Providers

Alibaba Anthropic Bedrock Cerebras Cohere DeepSeek Fireworks Google Groq Meta MiniMax Mistral Moonshot AI NVIDIA OpenAI Perplexity Thinking Machines Vertex xAI Xiaomi Z.ai
OpenAI Retired 2 params

OpenAI o1-preview API parameters

These are the API parameters modelparams.dev tracks for OpenAI o1-preview — the settings you send in a request. Each row gives the type, default, valid range or values, and the conditions that gate it. It's the same data the JSON API serves.

This model is retired. Shutdown date: 2025-07-28. Suggested replacement: openai/o3.

After the parameter count instead — how many weights o1-preview has? That's a different number, and we don't track it. Here's the difference.

Length 1 param
Parameter Type Default Description Condition
Max tokens
max_tokens 		integer (1…+∞) 4096 Maximum number of output tokens the model may generate. —
Reasoning 1 param
Parameter Type Default Description Condition
Reasoning effort
reasoning_effort 		enum (minimal | low | medium | high) "medium" Controls how much reasoning the model should perform before producing an answer. —

OpenAI o1-preview API parameters in brief

OpenAI o1-preview documents 2 API parameters, grouped by what they control:

Frequently asked questions

Which API parameters does OpenAI o1-preview support?
OpenAI o1-preview accepts 2 API parameters in the request body: max_tokens, reasoning_effort.
What is the default max_tokens for OpenAI o1-preview?
The default max_tokens for OpenAI o1-preview is 4096, with a minimum of 1.

Resources

All OpenAI models Glossary Full catalog

o1-preview — JSON

The full model definition as served by the API. Copy it or open the endpoint directly.

/api/v1/models/openai/o1-preview.json 
{
  "$schema": "https://modelparams.dev/api/v1/schema.json",
  "provider": "openai",
  "authType": "api_key",
  "model": "o1-preview",
  "status": "retired",
  "replacement": "openai/o3",
  "shutdownOn": "2025-07-28",
  "params": [
    {
      "path": "max_tokens",
      "label": "Max tokens",
      "description": "Maximum number of output tokens the model may generate.",
      "group": "generation_length",
      "type": "integer",
      "default": 4096,
      "range": {
        "min": 1
      }
    },
    {
      "path": "reasoning_effort",
      "label": "Reasoning effort",
      "description": "Controls how much reasoning the model should perform before producing an answer.",
      "group": "reasoning",
      "type": "enum",
      "default": "medium",
      "values": [
        "minimal",
        "low",
        "medium",
        "high"
      ]
    }
  ]
}

Other OpenAI models

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How to use

Building with an AI agent? Hit Copy to grab this whole guide as Markdown and paste it in — or point your agent straight at /llms.txt.

modelparams.dev is an open, community-maintained catalog of model parameters. Each entry shows the knobs you can turn — type, default, range, and the conditions that gate it.

The same model accessed via an API key and via a subscription usually exposes a different set of parameters. We list both as separate entries so the data stays honest.

Catalog API

The full catalog is static JSON, CORS-enabled, served from the edge.

curl https://modelparams.dev/api/v1/models.json

Each entry is keyed by provider/model for API-key variants; subscription variants append -subscription.

If you only need the params for one model contract, use the providerless endpoint. Subscription contracts are model slugs with -subscription. 

curl https://modelparams.dev/api/v1/models/openai/gpt-5.5.json
curl https://modelparams.dev/api/v1/models/openai/gpt-5.5-subscription.json

Single model

curl https://modelparams.dev/api/v1/models/anthropic/claude-opus-4-7.json
curl https://modelparams.dev/api/v1/models/anthropic/claude-opus-4-7-subscription.json

JSON Schema

Every entry validates against a JSON Schema you can use in your editor or pipeline. 

curl https://modelparams.dev/api/v1/schema.json

Add this header to any YAML you author for autocomplete in VS Code: 

# yaml-language-server: $schema=https://modelparams.dev/api/v1/schema.json

Logos

Provider logos are available at /assets/logos/{provider}.svg where {provider} is the provider slug. They use currentColor so they inherit your text color. 

curl https://modelparams.dev/assets/logos/anthropic.svg

Logos are sourced from the models.dev repo (MIT) and used under nominative fair use.

Contribute

The data lives in YAML under models/{provider}/{model}-{auth}.yaml in the GitHub repo. Open a PR; CI validates against the schema and rebuilds.

Edit on GitHub MIT licensed