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Overview

Hooks in Magma allow you to expose HTTP endpoints that external services can call to interact with your agent. They’re perfect for handling webhooks, callbacks, and API integrations.

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Implementation

To add a hook to your agent, use the @hook decorator:

import { MagmaAgent } from "@pompeii-labs/magma";
import { hook } from "@pompeii-labs/magma/decorators";
import { Request, Response } from 'express';

class MyAgent extends MagmaAgent {
    @hook('webhook')
    async handleWebhook(req: Request, res: Response) {
        const data = req.body;
        res.status(200).json({ status: "success", received: data });
    }
}

The first parameter is the name of the hook. The second parameter is optional, and is covered in the Advanced Usage section.

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Hook URLs

When your agent is deployed, hooks are automatically exposed at:

https://api.magmadeploy.com/v1/agents/<AGENT_ID>/hooks/<HOOK_NAME>

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Request Handling

Hooks support both GET and POST methods by default. The request and response objects are the standard Express Request and Response type, giving you access to:

  • req.query - URL query parameters
  • req.body - POST request body
  • req.headers - HTTP headers
  • req.params - URL parameters

You can also use the res object to send a response to the caller.

  • res.status(code).json(body) - Send a JSON response
  • res.send(body) - Send a string or buffer response
  • res.end() - End the response

For more information on the Express Request and Response objects, see the Express documentation.

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Common Use Cases

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OAuth Callbacks

class MyAgent extends MagmaAgent {
    @hook('oauth-callback')
    async handleOAuth(req: Request, res: Response) {
        const { code } = req.query;
        const tokens = await this.exchangeCodeForTokens(code as string);
        res.status(200).json({ success: true, tokens });
    }
}

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Webhook Listeners

class MyAgent extends MagmaAgent {
    @hook('stripe-webhook')
    async handleStripeEvent(req: Request, res: Response) {
        const event = req.body;
        switch (event.type) {
            case 'payment.succeeded':
                await this.processPayment(event.data);
                break;
            case 'subscription.created':
                await this.activateSubscription(event.data);
                break;
        }

        res.status(200).json({ received: true });
    }
}

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API Endpoints

class MyAgent extends MagmaAgent {
    @hook('status')
    async getStatus(req: Request, res: Response) {
        const metrics = await this.getSystemMetrics();
        res.status(200).json({
            status: "healthy",
            uptime: process.uptime(),
            metrics
        });
    }
}

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Best Practices

  1. Validation: Always validate incoming data
@hook('user-update')
async updateUser(req: Request) {
    const { userId, data } = req.body;
    if (!userId || !data) {
        throw new Error('Missing required fields');
    }
    await this.updateUserData(userId, data);
}
  1. Error Handling: Implement proper error handling
@hook('process-data')
async processData(req: Request, res: Response) {
    try {
        const result = await this.processPayload(req.body);
        res.status(200).json({ success: true, result });
    } catch (error) {
        res.status(500).json({
            success: false,
            error: error.message
        });
    }
}
  1. Security: Implement authentication when needed
@hook('secure-endpoint')
async secureEndpoint(req: Request, res: Response) {
    const apiKey = req.headers['x-api-key'];
    if (!apiKey || !this.validateApiKey(apiKey)) {
        res.status(401).json({ error: 'Unauthorized' });
    }
    const data = await this.getSecureData();
    res.status(200).json({ success: true, data });
}

Hooks are publicly accessible endpoints. Always implement appropriate security measures for sensitive operations.

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Advanced Usage

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Static Hooks

Some hooks don’t need to access the agent’s context. You can declare them as static methods:

@hook('user-update')
static async updateUser(req: Request, res: Response) {
    const { userId, data } = req.body;
}

This hook will be handled without instantiating the agent.

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Session-based Hooks

Sometimes you need a hook to be handled by a specific session. You can do this by utilizing the second parameter of the hook decorator:

@hook('user-update', HookRequest.Body('userId'))
async updateUser(req: Request, res: Response) {
    const { userId, data } = req.body;
}

This will direct the hook to the session with the id that matches the userId in the request body. To learn more about sessions, see the Sessions page.

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Limitations

  • File uploads are limited to 10MB
  • Webhook timeout is 30 seconds
  • Rate limiting applies based on your plan

For long-running operations, consider using a job instead of a hook, or implement an async pattern with a status endpoint.

MiddlewareJobs