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Providers

Alibaba Anthropic Cohere DeepSeek Google Meta MiniMax Mistral Moonshot AI Nvidia OpenAI Perplexity xAI Xiaomi Z.ai

Providers

Alibaba Anthropic Cohere DeepSeek Google Meta MiniMax Mistral Moonshot AI Nvidia OpenAI Perplexity xAI Xiaomi Z.ai
Anthropic 4 params

Anthropic Claude 3 Opus 20240229 parameters

These are the parameters modelparams.dev tracks for Anthropic Claude 3 Opus 20240229. 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.

Length 1 param
Parameter Type Default Description Condition
Max tokens
max_tokens 		integer (1…+∞) 4096 Maximum number of output tokens the model may generate. —
Sampling 3 params
Parameter Type Default Description Condition
Temperature
temperature 		number (0…1 step 0.1) 1 Controls randomness. Lower values make outputs more focused; higher values make them more varied.
Not when thinking.type ∈ {"adaptive", "enabled"}
Top P
top_p 		number (0…1 step 0.01) 1 Controls nucleus sampling by limiting generation to tokens whose cumulative probability reaches this value.
Not when thinking.type ∈ {"adaptive", "enabled"} or temperature ≠ 1
Top K
top_k 		integer (0…+∞) 0 Limits token sampling to the top K most likely next tokens.
Not when thinking.type ∈ {"adaptive", "enabled"}

Anthropic Claude 3 Opus 20240229 parameters in brief

Anthropic Claude 3 Opus 20240229 documents 4 API parameters, grouped by what they control:

Resources

All Anthropic models Glossary Full catalog

Claude 3 Opus 20240229 — JSON

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

/api/v1/models/anthropic/claude-3-opus-20240229.json 
{
  "$schema": "https://modelparams.dev/api/v1/schema.json",
  "provider": "anthropic",
  "authType": "api_key",
  "model": "claude-3-opus-20240229",
  "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": "temperature",
      "label": "Temperature",
      "description": "Controls randomness. Lower values make outputs more focused; higher values make them more varied.",
      "group": "sampling",
      "applicability": {
        "except": {
          "thinking.type": [
            "adaptive",
            "enabled"
          ]
        }
      },
      "type": "number",
      "default": 1,
      "range": {
        "min": 0,
        "max": 1,
        "step": 0.1
      }
    },
    {
      "path": "top_p",
      "label": "Top P",
      "description": "Controls nucleus sampling by limiting generation to tokens whose cumulative probability reaches this value.",
      "group": "sampling",
      "applicability": {
        "except": [
          {
            "thinking.type": [
              "adaptive",
              "enabled"
            ]
          },
          {
            "temperature": {
              "not": 1
            }
          }
        ]
      },
      "type": "number",
      "default": 1,
      "range": {
        "min": 0,
        "max": 1,
        "step": 0.01
      }
    },
    {
      "path": "top_k",
      "label": "Top K",
      "description": "Limits token sampling to the top K most likely next tokens.",
      "group": "sampling",
      "applicability": {
        "except": {
          "thinking.type": [
            "adaptive",
            "enabled"
          ]
        }
      },
      "type": "integer",
      "default": 0,
      "range": {
        "min": 0
      }
    }
  ]
}

Other Anthropic models

Claude 3 Opus Latest 4 params View Claude 3.5 Haiku 20241022 4 params View Claude 3.5 Haiku Latest 4 params View Claude 3.5 Sonnet 20241022 4 params View Claude 3.5 Sonnet Latest 4 params View Claude 3.7 Sonnet 20250219 6 params View Claude 3.7 Sonnet Latest 6 params View Claude Fable 5 4 params View Claude Fable 5 Subscription 4 params View Claude Haiku 4 6 params View Claude Haiku 4 Subscription 6 params View Claude Haiku 4.5 6 params View Claude Haiku 4.5 Subscription 6 params View Claude Haiku 4.5 20251001 6 params View Claude Haiku 4.5 20251001 Subscription 6 params View Claude Opus 4 Subscription 6 params View Claude Opus 4 20250514 7 params View Claude Opus 4 20250514 Subscription 7 params View Claude Opus 4.1 20250805 7 params View Claude Opus 4.1 20250805 Subscription 7 params View Claude Opus 4.5 20251101 8 params View Claude Opus 4.5 20251101 Subscription 8 params View Claude Opus 4.6 8 params View Claude Opus 4.6 Subscription 8 params View Claude Opus 4.7 4 params View Claude Opus 4.7 Subscription 4 params View Claude Opus 4.8 4 params View Claude Opus 4.8 Subscription 4 params View Claude Sonnet 4 Subscription 6 params View Claude Sonnet 4 20250514 7 params View Claude Sonnet 4 20250514 Subscription 7 params View Claude Sonnet 4.5 6 params View Claude Sonnet 4.5 Subscription 6 params View Claude Sonnet 4.5 20250929 6 params View Claude Sonnet 4.5 20250929 Subscription 6 params View Claude Sonnet 4.6 8 params View Claude Sonnet 4.6 Subscription 8 params View

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/params/gpt-5.5.json
curl https://modelparams.dev/api/v1/params/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