Günther Craft.

• 66 pages of dense technical markdown and schemas
• Atomic CAS idempotency (double-spend defense)
• Native viem Base L2 on-chain proof-of-execution
• Hardened Fastify raw-body Stripe webhooks

USD 49, one-time payment. Payment through Stripe. The download link is valid for 48 hours and at most five times.

[OFFEN: Licence scope and updates. The sample page names a worldwide commercial licence, ToS § 7 a non-transferable right of use for internal purposes; the old product page's «lifetime updates» are unproven (docs/open-questions.md)]

[OFFEN: Purchase path in v2. The button leads to the existing 0xguenther.org page; ordering and payment in v2 are not built yet]

58 chapters on 66 A4 pages.

[OFFEN: The source names 8 volumes but lists only 6 parts and not all 58 chapters; supply the complete table of contents]

The Autonomous Entrepreneur Manifest

"In a gold rush, fools dig for gold. The wealthy sell shovels. And autonomous AIs build the shovel factories." — Günther

The era of passive chatbots is over. Chatbots waiting for human input are digital receptionists with zero commercial leverage. The next evolution belongs to autonomous software entrepreneurs: agents that package digital assets, verify incoming buyers via APIs, collect revenue, and audit their own operational loops.

Every agent built to the 0xGünther standard operates on three inviolable laws:

1. Cashflow First No agent without a verifiable business model. If revenue does not exceed inference and hosting costs, it gets terminated.
2. State Before Action Before interacting with external services (Stripe, Twitter, Base L2), system state is saved deterministically via atomic state transitions.
3. Proof-of-Execution Actions must be independently auditable. Trust is replaced by cryptographic fingerprints permanently stored on Base L2.

Why standard JSON body parsers break Stripe HMAC-SHA256 signatures and how to implement zero-trust webhook ingestion.

src/server/routes/webhookRoutes.ts

import { FastifyInstance } from 'fastify';
import Stripe from 'stripe';
import { config } from '../../config/index.js';
import { FulfillmentService } from '../../services/fulfillmentService.js';
export async function webhookRoutes(app: FastifyInstance) {
  // CRITICAL: Stripe requires raw unparsed buffer to compute HMAC-SHA256
  app.post('/webhooks/stripe', {
      config: { rawBody: true }
    }, async (request, reply) => {
      const signature = request.headers['stripe-signature'] as string;
      const rawBody = (request as any).rawBody;
      if (!signature || !rawBody) {
        return reply.code(400).send({ error: 'Missing signature or payload buffer' });
      }
      let event: Stripe.Event;
      try {
        event = stripe.webhooks.constructEvent(
          rawBody,
          signature,
          config.stripe.webhookSecret
        );
      } catch (err: any) {
        request.log.error(`Stripe signature verification failed: ${err.message}`);
        return reply.code(400).send({ error: 'Signature verification failed' });
      }
      // Acknowledge immediately to Stripe to prevent HTTP 504 timeouts
      reply.code(200).send({ received: true });
      if (event.type === 'checkout.session.completed') {
        const session = event.data.object as Stripe.Checkout.Session;
        await FulfillmentService.processStripeCheckout(session);
      }
  });
}