Generating a Typed Client

The Outpost API is described by an OpenAPI 3.1 document, generated from the same route schemas the server enforces at runtime. That means you never have to hand-write request or response types: generate them from the spec and they are correct by construction.

The API serves its own spec at GET /v1/openapi.json (no authentication required), so you can generate against any environment you can reach.

1. Generate types with openapi-typescript

openapi-typescript converts the spec into a single .ts file of types, with zero runtime code.

npm install -D openapi-typescript typescript
npx openapi-typescript "$OUTPOST_URL/v1/openapi.json" -o ./src/outpost-api.ts

Re-run the command whenever the API changes; the diff of the generated file shows you exactly what changed in the contract.

2. Call the API with openapi-fetch

openapi-fetch is a tiny (~6 kB) fetch wrapper that consumes those types. Paths, methods, path/query parameters, request bodies, and response shapes are all checked at compile time.

npm install openapi-fetch

import createClient from 'openapi-fetch';
import type { paths } from './outpost-api';

const api = createClient<paths>({
  baseUrl: process.env.OUTPOST_URL,
  headers: { 'x-api-key': process.env.OUTPOST_API_KEY },
});

// Fully typed: TypeScript knows this endpoint, its body shape, and its 202 response.
const { data, error } = await api.POST('/v1/messages/sms', {
  body: {
    items: [{ to: '+15551234567', body: 'Hello from Outpost!' }],
    communicationId: 'welcome-blast-1',
  },
});

if (error) {
  // `error` is the typed error response body.
  console.error('Send failed:', error);
} else {
  // `data` is the typed 202 payload with per-item outcomes.
  console.log('Accepted:', data.accepted, 'Rejected:', data.rejected);
}

Every request returns { data, error } rather than throwing, and both sides are typed from the spec. A typo in a path, a missing required field, or reading a property that does not exist on the response is a compile error, not a production bug.

Authentication is a project-scoped API key in the x-api-key header. See API Keys & Authentication for roles and scoping.

Inside the Outpost monorepo

The dashboard follows the same generate-from-spec path as any other TypeScript consumer. Types are produced from the committed document at packages/api/openapi.json (npm run generate:api in packages/dashboard, hooked to predev / prebuild).

After changing an API route schema, regenerate the committed document first:

npm run generate:openapi -w @outpost/api

Other languages

The spec is a standard OpenAPI 3.1 document, so any OpenAPI generator works, for example openapi-generator for Python, Go, Java, and others:

openapi-generator generate -i "$OUTPOST_URL/v1/openapi.json" -g python -o ./outpost-client

Browsing the contract

The full endpoint-by-endpoint contract, with schemas and error responses, lives in the API Reference section of these docs, generated from the same OpenAPI document.