---

modelparams.dev

An open, community-maintained catalog of LLM model parameters.

Every parameter each AI model accepts, in one place. Inspired by models.dev; we use it at Manifest.

TypeScript

npm install modelparams

ParamsOf<Id> is the exact set of parameters a model accepts. Pass one it doesn't, and your code won't compile.

import type { ParamsOf } from "modelparams";
import OpenAI from "openai";

const params: ParamsOf<"openai/gpt-4.1"> = {
  max_tokens: 1024,
  temperature: 0.7,
  // top_k: 40, // won't compile: gpt-4.1 has no top_k
};

await new OpenAI().chat.completions.create({ model: "gpt-4.1", messages, ...params });

Defaults, runtime validation, and the helper APIs are in the package README.

API

Prefer raw JSON?

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

Schema at https://modelparams.dev/api/v1/schema.json, per the Model Parameters convention.

Adding a model

Drop a YAML file in models/<provider>/, open a PR, and CI validates it against the schema. Details in CONTRIBUTING.md. Can't open a PR? File an issue with a link to the docs.

Local development

npm install
npm run dev          # http://localhost:3000
npm run build        # → dist/
npm run validate     # check every YAML
npm test

License

MIT