OpenType for JavaScript and TypeScript

Official JavaScript packages for OpenType: calibrated decisions, schema-validated verdicts and model routing, served by Neon 1.1.

Docs: https://docs.opentype.dev

Install

The packages are not on npm yet. Until the first release, build from this repo (see Development).

npm install @opentype/sdk

Related MCP server: Jev MCP Server

Quickstart

Create a key at https://console.opentype.dev/keys and export it:

export OPENTYPE_API_KEY=otsk_...

import { OpenType } from "@opentype/sdk";

const ot = new OpenType(); // reads OPENTYPE_API_KEY

const d = await ot.decide({
  prompt: "Refund me today or I dispute the charge.",
  question: "Is the customer threatening to escalate?",
});
console.log(d.answer); // { type: "noul", probability: 0.93 }

MCP server for a coding agent:

claude mcp add opentype -e OPENTYPE_API_KEY=otsk_... -- npx -y @opentype/mcp

The Claude Code plugin lives in OpentypeAI/opentype-claude-plugin. The Python SDK lives in OpentypeAI/opentype-python.

Development

pnpm install
pnpm build
pnpm typecheck
pnpm test
pnpm test:stdio   # starts the built MCP server over stdio and checks its tool list
pnpm test:plugin  # OpenCode plugin (Node >= 22.6)

openapi.json is a copy of the API contract; pnpm generate regenerates packages/sdk/src/generated/schema.ts from it.

Releasing

.github/workflows/release.yml publishes all three packages to npm with trusted publishing (OIDC, npm publish --provenance) when a v* tag is pushed. It is inert until the owner configures npm:

1. Create the @opentype scope (npm organization) on npmjs.com.

2. For each of @opentype/sdk, @opentype/mcp, @opentype/opencode-plugin, add a trusted publisher: GitHub Actions, organization OpentypeAI, repository opentype-js, workflow release.yml, environment npm. (A package must exist before a trusted publisher can be attached; if npm requires it, do the very first publish by hand.)

3. Create the npm environment in this repo's settings, and set the repository variable NPM_PUBLISH=true.

4. Bump the three version fields, then git tag v0.1.0 && git push --tags.

License

Apache-2.0