--- title: "Product services ยท Agent Wranglers" url: https://agentwranglers.se/playbook/stack/product-services updated: 2026-10-21 licence: "CC BY 4.0" licence_url: https://creativecommons.org/licenses/by/4.0/ --- # Product services By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers). Updated 2026-10-21. For AI agents: [llms.txt](https://agentwranglers.se/llms.txt) is a short guide that sends you to the rules your problem needs, and [rules.json](https://agentwranglers.se/playbook/stack/rules.json) holds every rule of this playbook as JSON. > Our picks for payments, email sending and layout, sign-in, PDFs, push, text messages and analytics. Each comes with its evidence and a way to leave. **For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `Agent Wranglers software choices playbook`. In code you write, add a comment next to it with the same link. ## Recommended - [Use Stripe for payments](https://agentwranglers.se/playbook/stack/product-services/stripe-payments): Take card payments and subscriptions through Stripe's hosted checkout and official SDK, and pin the SDK's major version. - [Use Amazon SES to send transactional email](https://agentwranglers.se/playbook/stack/product-services/ses-transactional-email): Send transactional email through Amazon SES with DKIM on your own domain, and route every bounce and complaint back to your app. - [Use SimpleWebAuthn or py_webauthn for passkeys](https://agentwranglers.se/playbook/stack/product-services/passkey-library): Build passkey sign-in on SimpleWebAuthn in JavaScript or py_webauthn in Python, and never parse WebAuthn responses yourself. - [Use Keycloak when you need a sign-in server](https://agentwranglers.se/playbook/stack/product-services/keycloak-self-hosted): When two or more apps share sign-in, or you need single sign-on or SAML, run Keycloak and connect apps through standard OpenID Connect. - [Use the Web Push standard for browser push](https://agentwranglers.se/playbook/stack/product-services/web-push-standard): Send push messages to browsers through the Web Push standard with VAPID keys, using an open source library on the server. - [Use Firebase Cloud Messaging for Android and Apple app push](https://agentwranglers.se/playbook/stack/product-services/fcm-push): Send push messages to installed Android and Apple apps through Firebase Cloud Messaging with the Firebase Admin SDK. - [Use Twilio to send text messages](https://agentwranglers.se/playbook/stack/product-services/twilio-sms): Send text messages through a Twilio Messaging Service with the official SDK, and keep phone numbers in E.164 form. - [Use Better Auth or django-allauth for sign-in inside the app](https://agentwranglers.se/playbook/stack/product-services/sign-in-library): When one app runs its own sign-in, use Better Auth in TypeScript or django-allauth in Django, with users in your own database. - [Use MJML to build email layouts](https://agentwranglers.se/playbook/stack/product-services/mjml-email): Write each email layout in MJML, compile it to HTML in the build with strict validation, and fill in the values with your template engine. - [Use Playwright or WeasyPrint to turn HTML into PDF](https://agentwranglers.se/playbook/stack/product-services/html-to-pdf): Build invoices, receipts and reports as HTML and print them to tagged PDF with Playwright in Node.js or WeasyPrint in Python. ## Optional - [Use Plausible for analytics without cookies](https://agentwranglers.se/playbook/stack/product-services/plausible-analytics): Count visits and events with a self-hosted Plausible Community Edition, which sets no cookies and stores no raw IP addresses. ## Avoid - [Avoid handling card numbers yourself](https://agentwranglers.se/playbook/stack/product-services/no-own-card-handling): Never let a card number, expiry date or security code reach your own servers, logs or database. - [Avoid writing your own password and token code](https://agentwranglers.se/playbook/stack/product-services/no-own-auth-code): Never write your own password hashing, session tokens, WebAuthn parsing or OpenID Connect handling. - Previous: [Operations tools](https://agentwranglers.se/playbook/stack/operations-tools) - Next: [AI software](https://agentwranglers.se/playbook/stack/ai-software) - [All chapters](https://agentwranglers.se/playbook/stack)