Add Plugin

You are helping a developer add a new custom plugin to their Corsair integration so they can call a third-party API through Corsair's pipeline.

Step 1: Gather Requirements

Ask the developer two questions before doing anything else:

1. What API/service do you want to integrate? (e.g., "Stripe", "Twilio", "Notion", "OpenAI")
2. What do you want to be able to do with it? List specific actions (e.g., "create customers and charge them", "send SMS messages", "read and update pages")

Step 2: Research the API

Use WebSearch or WebFetch to look up the API documentation. Find:

• The API base URL (e.g., https://api.stripe.com/v1)
• How authentication works (Bearer token, X-API-Key header, etc.)
• The exact endpoints the developer needs: URL paths, HTTP methods, request body/query fields, and response shape

Step 3: Scaffold the Plugin

Run the scaffold command:

npm run new-plugin <PluginName>

Use PascalCase (e.g., Stripe, Twilio, OpenAI). This creates server/plugins/<pluginname>.ts with a single-file boilerplate.

Step 4: Implement the Plugin

Open the generated file and fill it in based on the API docs:

1. Update API_BASE to the correct base URL.

2. Update the auth header to match the API:

// Bearer token (most common)
Authorization: `Bearer ${apiKey}`,

// API key in header
'X-API-Key': apiKey,

// Basic auth
Authorization: `Basic ${Buffer.from(`${apiKey}:`).toString('base64')}`,

3. Replace response types with actual shapes from the API docs:

type Customer = {
  id: string;
  email: string;
  name: string | null;
  created: number;
};

4. Replace the example endpoints with the ones the developer needs:

const customersGet: CorsairEndpoint<StripeContext, { id: string }, Customer> = async (ctx, input) => {
  return apiRequest<Customer>(`customers/${input.id}`, ctx.key);
};

const customersCreate: CorsairEndpoint<StripeContext, { email: string; name?: string }, Customer> = async (ctx, input) => {
  return apiRequest<Customer>('customers', ctx.key, {
    method: 'POST',
    body: { email: input.email, name: input.name },
  });
};

5. Update the endpoint tree to group related endpoints:

const endpoints = {
  customers: {
    get: customersGet,
    create: customersCreate,
    list: customersList,
  },
  charges: {
    create: chargesCreate,
  },
} as const;

6. Update the plugin function name and id to match your plugin name.

The full structure of a complete single-file plugin looks like this:

import type {
  BindEndpoints,
  CorsairEndpoint,
  CorsairPlugin,
  CorsairPluginContext,
} from 'corsair/core';

type StripeOptions = { key: string };

const StripeSchema = { version: '1.0.0', entities: {} } as const;

type StripeContext = CorsairPluginContext<typeof StripeSchema, StripeOptions>;

type Customer = { id: string; email: string; name: string | null };

const API_BASE = 'https://api.stripe.com/v1';

async function apiRequest<T>(
  path: string,
  apiKey: string,
  options: {
    method?: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH';
    body?: Record<string, unknown>;
    query?: Record<string, string | number | boolean | undefined>;
  } = {},
): Promise<T> {
  const { method = 'GET', body, query } = options;
  const url = new URL(`${API_BASE}/${path}`);
  if (query) {
    for (const [k, v] of Object.entries(query)) {
      if (v !== undefined) url.searchParams.set(k, String(v));
    }
  }
  const res = await fetch(url.toString(), {
    method,
    headers: {
      Authorization: `Bearer ${apiKey}`,
      'Content-Type': 'application/json',
    },
    body: body ? JSON.stringify(body) : undefined,
  });
  if (!res.ok) {
    throw new Error(`Stripe API error: ${res.status} ${res.statusText}`);
  }
  // 204 No Content
  if (res.status === 204) return { success: true } as T;
  return res.json() as Promise<T>;
}

const customersGet: CorsairEndpoint<StripeContext, { id: string }, Customer> = async (ctx, input) => {
  return apiRequest<Customer>(`customers/${input.id}`, ctx.key);
};

const endpoints = {
  customers: { get: customersGet },
} as const;

const webhooks = {} as const;

const defaultAuthType = 'api_key' as const;

// ── Plugin Types ──────────────────────────────────────────────────────────────

export type BoundEndpoints = BindEndpoints<typeof endpoints>;

export type StripePlugin<PluginOptions extends StripeOptions> = CorsairPlugin<
  'stripe',
  typeof StripeSchema,
  typeof endpoints,
  typeof webhooks,
  PluginOptions,
  typeof defaultAuthType
>;

export function stripe<const PluginOptions extends StripeOptions>(
  options: StripeOptions & PluginOptions = {} as StripeOptions & PluginOptions,
): StripePlugin<PluginOptions> {
  return {
    id: 'stripe',
    schema: StripeSchema,
    options,
    endpoints,
    keyBuilder: async (_ctx, source) => {
      if (source === 'endpoint') return options.key;
      return '';
    },
  };
}

Step 5: Register the Plugin in Corsair

Open server/corsair.ts and add the plugin import and registration:

import { createCorsair, googlecalendar, linear, resend, slack } from 'corsair';
import { stripe } from './plugins/stripe'; // add this
import { pool } from './db';

export const corsair = createCorsair({
  plugins: [slack(), linear(), resend(), googlecalendar(), stripe({ key: process.env.STRIPE_API_KEY! })], // add plugin here
  database: pool,
  kek: process.env.CORSAIR_KEK!,
  multiTenancy: false,
});

Remind the developer to add the API key environment variable (e.g., STRIPE_API_KEY) to their .env file.

Step 6: Add Seed Examples

Open server/seed/examples.ts and add 2–3 examples showing how to use the new plugin. These are used by the AI agent to understand how to write code against this API.

Each example has a description (plain English, used for search) and code (a runnable async function):

{
  description:
    'Get a Stripe customer by their ID. Returns customer details including email, name, and metadata.',
  code: `async function main() {
  const customer = await corsair.stripe.api.customers.get({ id: 'cus_xxx' });
  console.log(customer);
}
main().catch(console.error);`,
},
{
  description:
    'Create a new Stripe customer with an email address.',
  code: `async function main() {
  const customer = await corsair.stripe.api.customers.create({
    email: 'user@example.com',
    name: 'Jane Doe',
  });
  console.log(customer.id);
}
main().catch(console.error);`,
},

The API call pattern is always: corsair.<pluginId>.api.<endpointGroup>.<method>(input)

Key Rules

• All plugin code lives in a single file (server/plugins/<name>.ts). No subdirectories.
• The developer passes the API key directly: stripe({ key: process.env.STRIPE_API_KEY! }). No key manager needed.
• Use ctx.key inside endpoint implementations — Corsair populates it from the keyBuilder.
• Keep types simple — inline response types are fine. No need for complex generics or separate type files.
• The id field in the plugin must be a unique string (lowercase, no spaces). It becomes the property name on corsair.*.