modelparams.dev
Anthropic API key 6 params

Anthropic Claude Haiku 4.5 parameters

These are the parameters modelparams.dev tracks for Anthropic Claude Haiku 4.5. 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.

Parameter Type Default Description Condition
Length · 1 param
Max tokens
max_tokens 		integer (1…+∞) 4096 Maximum number of output tokens the model may generate. —
Sampling · 3 params
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"}
Reasoning · 2 params
Thinking mode
thinking.type 		enum (disabled | enabled) "disabled" Controls the Anthropic thinking mode values supported by this model. —
Budget tokens
thinking.budget_tokens 		integer (1024…+∞) 4096 Maximum token budget Anthropic may use for extended thinking before producing the final answer.
Only when thinking.type = "enabled"
This model as JSON All Anthropic models Parameter glossary Full catalog

Other Anthropic models

Claude 3 Opus 20240229 Claude 3 Opus Latest Claude 3.5 Haiku 20241022 Claude 3.5 Haiku Latest Claude 3.5 Sonnet 20241022 Claude 3.5 Sonnet Latest Claude 3.7 Sonnet 20250219 Claude 3.7 Sonnet Latest Claude Haiku 4 Claude Haiku 4 subscription Claude Haiku 4.5 20251001 Claude Opus 4 subscription Claude Opus 4.1 20250805 Claude Opus 4.20250514 Claude Opus 4.5 20251101 Claude Opus 4.6 Claude Opus 4.7 Claude Sonnet 4 subscription Claude Sonnet 4.20250514 Claude Sonnet 4.5 Claude Sonnet 4.5 20250929 Claude Sonnet 4.6

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 LLM 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.

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