modelparams.dev
Reasoning integer 26 models

Budget tokens thinking.budget_tokens

Maximum token budget Anthropic may use for extended thinking before producing the final answer.

Type
integer
Default
4096
Range
1024 – +∞

thinking.budget_tokens by model

The exact type, default, range, and conditions for thinking.budget_tokens on each model that documents it.

Model Provider Type Default Range / values Condition
Claude 3.7 Sonnet 20250219 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude 3.7 Sonnet Latest Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4.5 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4.5 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4.5 20251001 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Haiku 4.5 20251001 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4 20250514 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4 20250514 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.1 20250805 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.1 20250805 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.5 20251101 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.5 20251101 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.6 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Opus 4.6 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4 20250514 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4 20250514 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.5 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.5 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.5 20250929 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.5 20250929 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.6 Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"
Claude Sonnet 4.6 Subscription Anthropic integer 4096 1024…+∞
Only when thinking.type = "enabled"

Models without thinking.budget_tokens documented yet

These models don't list thinking.budget_tokens in the catalog. That may mean the provider doesn't accept it, or it simply hasn't been added yet — the data is community-maintained.

Related reasoning parameters

Resources

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