Overview - Corsair

Use fal through Corsair: one client, typed API calls, and incoming webhooks. Every model on fal takes its own input fields. Look them up with models.search({ endpointIds: ['<endpoint id>'], includeOpenApi: true }), then pass them as input. Video, audio and training runs usually take minutes. After submitting, models.run waits up to 10 seconds (at most 15). When it sees the run end within the wait, it answers a final state: SUCCEEDED with output, or FAILED with error (bad input or a model error), and there is nothing to follow. Any other answer carries the run’s response_url and IN_PROGRESS or IN_QUEUE. IN_QUEUE also covers a read that failed or ran out of time, so the run may already have started or even finished at fal. Follow every IN_QUEUE or IN_PROGRESS answer with queue.status({ responseUrl }) until it says SUCCEEDED or FAILED, or pass webhookUrl and let fal post the result. On Corsair’s cloud, get_job and the job card do the following for you. What you get:

14 typed API operations
1 incoming webhook event types

Setup

Install

npm install corsair @corsair-dev/fal

yarn add corsair @corsair-dev/fal

pnpm install corsair @corsair-dev/fal

bun add corsair @corsair-dev/fal

Add the plugin

corsair.ts

import Database from 'better-sqlite3';
import { createCorsair } from 'corsair';
import { fal } from '@corsair-dev/fal';

export const corsair = createCorsair({
	plugins: [
		fal(),
	],
	database: new Database('corsair.db'),
	kek: process.env.CORSAIR_KEK!,
	multiTenancy: true,
	hub: {
		projectApiKey: process.env.CORSAIR_API_KEY!,
		signingSecret: process.env.CORSAIR_SIGNING_SECRET!,
	},
});

With multiTenancy: true, scope calls with corsair.withTenant(id). See Quick start for KEK + Hub keys, and Multi-tenancy for account isolation.

Choose authentication

API Key (Recommended)

No setup required yet. When you make your first request as a tenant, Corsair prompts for the API key.

fal()

More: API Key

Connect a tenant

Mint a connect link and send the tenant to it. Hub hosts the page and delivers the result to your app — see Connect / OAuth.

const { connectUrl } = await corsair.manage.connect.createLink({
	plugin: 'fal',
	tenantId: 'acme',
});
// redirect the user's browser to connectUrl

Example API calls

Find text-to-video models

const tenant = corsair.withTenant('acme');
await tenant.fal.api.models.search({ category: 'text-to-video', limit: 5 });

Generate an image

const tenant = corsair.withTenant('acme');
await tenant.fal.api.queue.submit({
	endpointId: 'fal-ai/flux/schnell',
	input: { prompt: 'A watercolor lighthouse on a cliff at dawn', image_size: 'square_hd' },
});

See the full list on the API page.

Webhooks

Pass webhookUrl to queue.submit and fal POSTs the result there when the request finishes. Hand processWebhook the raw body text (await request.text()), not parsed JSON. fal signs the exact bytes it sent; a parsed body is rebuilt as a best effort, which fails for outputs with whole-number floats or integers past 2^53. To hold deliveries to one fal account, store its fal user id (the x-fal-webhook-user-id header) as the account’s user_id.

fal({
    webhookHooks: {
        requests: {
            completed: {
                after: async (ctx, result) => {
                    if (result.data?.status === 'OK') console.log(result.data.request_id, result.data.payload);
                }
            },
        },
    },
})

Mount your framework handler once (see Frameworks), then point the provider at that URL. Full event list: Webhooks. Concepts: Webhooks, Hooks.

What’s next

API reference

Every fal.api.* operation with input and output types.

Webhooks

Event paths, payloads, and webhookHooks examples.

Connect / OAuth

createLink, Hub delivery, and tenant connect flows.

Use with agents

Expose this plugin’s operations as MCP tools.

​Setup

​Example API calls

​Webhooks

​What’s next

API reference

Webhooks

Connect / OAuth

Use with agents

Setup

Example API calls

Webhooks

What’s next