Add authentication rule for Fastify with @fastify/jwt and @fastify/auth

.changeset/add-authentication-rule.md

@@ -0,0 +1,5 @@
+---
+"@thecodepace/fastify-skills": minor
+---
+
+Add authentication rule for Fastify with @fastify/jwt and @fastify/auth patterns

AGENTS.md

@@ -24,6 +24,8 @@ Rules are stored in `skills/fastify-best-practise/rules/`:
 | Encapsulation           | `encapsulation.md`            | HIGH       |
 | Error Handling          | `error-handling.md`           | HIGH       |
 | Hooks & Lifecycle       | `hooks-lifecycle.md`          | MEDIUM     |
+| Logging                 | `logging.md`                  | HIGH       |
+| Authentication          | `authentication.md`           | HIGH       |
 | Testing                 | `testing.md`                  | HIGH       |
 | TypeScript              | `typescript-integration.md`   | MEDIUM     |
 | Decorators              | `decorators.md`               | MEDIUM     |

README.md

@@ -20,6 +20,8 @@ Apply Fastify best practices when creating servers, plugins, routes, schemas, ho
 | Encapsulation           | HIGH       | Proper scope isolation and when to use `fastify-plugin`                    |
 | Error Handling          | HIGH       | Custom error handlers, `@fastify/error`, `@fastify/sensible`, 404 handling |
 | Hooks & Lifecycle       | MEDIUM     | Full lifecycle hook coverage: request pipeline (`onRequest` → `onResponse`), application hooks (`onReady`, `onClose`), scoped hooks, and async/callback patterns |
+| Logging                 | HIGH       | Built-in Pino logger, request correlation, redaction, child loggers          |
+| Authentication          | HIGH       | JWT auth with `@fastify/jwt`, multi-strategy with `@fastify/auth`            |
 | Testing                 | HIGH       | Test with `inject()`, buildServer pattern, vitest/node:test                |
 | TypeScript              | MEDIUM     | Type providers, module augmentation, typed decorators                      |
 | Decorators              | MEDIUM     | Extend the Fastify instance, request, and reply with `decorate` / `decorateRequest` / `decorateReply` |

skills/fastify-best-practise/SKILL.md

@@ -17,19 +17,20 @@ A curated set of rules and patterns for building production-ready Fastify applic
 
 The rules are organized by topic in the `rules/` directory. Each rule follows a consistent format with impact rating, incorrect/correct examples, and references to official docs.
 
-| Rule                    | File                                                         | Impact     | Description                                                                                           |
-| ----------------------- | ------------------------------------------------------------ | ---------- | ----------------------------------------------------------------------------------------------------- |
-| Create Server           | [create-server.md](rules/create-server.md)                   | LOW-MEDIUM | Use a `buildServer()` factory function for reusable, testable server setup                            |
-| Create Plugin           | [create-plugin.md](rules/create-plugin.md)                   | LOW-MEDIUM | Encapsulate reusable functionality in plugins with `fastify-plugin`                                   |
-| Autoload                | [autoload.md](rules/autoload.md)                             | HIGH       | Automatically load plugins and routes from the filesystem with `@fastify/autoload`                    |
-| Route Best Practices    | [route-best-practices.md](rules/route-best-practices.md)     | MEDIUM     | Organize routes with plugins/prefixes, use async handlers, full route options                         |
-| Schema Validation (Zod) | [schema-validation-zod.md](rules/schema-validation-zod.md)   | HIGH       | Type-safe validation with Zod + `fastify-type-provider-zod`                                           |
-| Encapsulation           | [encapsulation.md](rules/encapsulation.md)                   | HIGH       | Proper scope isolation and when to use `fastify-plugin`                                               |
-| Error Handling          | [error-handling.md](rules/error-handling.md)                 | HIGH       | Custom error handlers, `@fastify/error`, 404 handling, structured responses                           |
-| Hooks & Lifecycle       | [hooks-lifecycle.md](rules/hooks-lifecycle.md)               | MEDIUM     | All request/reply and application hooks: onRequest, preParsing, preValidation, preHandler, preSerialization, onError, onSend, onResponse, onTimeout, onRequestAbort, onReady, onListen, onClose, onRoute, onRegister |
+| Rule                    | File                                                         | Impact     | Description                                                                        |
+| ----------------------- | ------------------------------------------------------------ | ---------- | ---------------------------------------------------------------------------------- |
+| Create Server           | [create-server.md](rules/create-server.md)                   | LOW-MEDIUM | Use a `buildServer()` factory function for reusable, testable server setup         |
+| Create Plugin           | [create-plugin.md](rules/create-plugin.md)                   | LOW-MEDIUM | Encapsulate reusable functionality in plugins with `fastify-plugin`                |
+| Autoload                | [autoload.md](rules/autoload.md)                             | HIGH       | Automatically load plugins and routes from the filesystem with `@fastify/autoload` |
+| Route Best Practices    | [route-best-practices.md](rules/route-best-practices.md)     | MEDIUM     | Organize routes with plugins/prefixes, use async handlers, full route options      |
+| Schema Validation (Zod) | [schema-validation-zod.md](rules/schema-validation-zod.md)   | HIGH       | Type-safe validation with Zod + `fastify-type-provider-zod`                        |
+| Encapsulation           | [encapsulation.md](rules/encapsulation.md)                   | HIGH       | Proper scope isolation and when to use `fastify-plugin`                            |
+| Error Handling          | [error-handling.md](rules/error-handling.md)                 | HIGH       | Custom error handlers, `@fastify/error`, 404 handling, structured responses        |
+| Hooks & Lifecycle       | [hooks-lifecycle.md](rules/hooks-lifecycle.md)               | MEDIUM     | All request/reply and application hooks: onRequest, preParsing, preValidation, preHandler, preSerialization, onError, onSend, onResponse, onTimeout, onRequestAbort, onReady, onListen, onClose, onRoute, onRegister                           |
 | Logging                 | [logging.md](rules/logging.md)                               | HIGH       | Built-in Pino logger, request correlation, redaction, child loggers                                   |
-| Testing                 | [testing.md](rules/testing.md)                               | HIGH       | Test with `inject()`, buildServer pattern, vitest/node:test                                           |
-| TypeScript              | [typescript-integration.md](rules/typescript-integration.md) | MEDIUM     | Type providers, module augmentation, typed decorators                                                 |
+| Authentication          | [authentication.md](rules/authentication.md)                 | HIGH       | JWT auth with `@fastify/jwt`, multi-strategy with `@fastify/auth`                  |
+| Testing                 | [testing.md](rules/testing.md)                               | HIGH       | Test with `inject()`, buildServer pattern, vitest/node:test                        |
+| TypeScript              | [typescript-integration.md](rules/typescript-integration.md) | MEDIUM     | Type providers, module augmentation, typed decorators                              |
 | Decorators              | [decorators.md](rules/decorators.md)                         | MEDIUM     | Extend the Fastify instance, request, and reply with `decorate` / `decorateRequest` / `decorateReply` |
 
 ## Usage
@@ -40,7 +41,7 @@ When generating Fastify code, read the relevant rule file(s) for the topic and a
 - **Adding routes**: `route-best-practices.md`, `autoload.md`, `schema-validation-zod.md`
 - **Adding shared services**: `create-plugin.md`, `autoload.md`, `encapsulation.md`
 - **Error handling**: `error-handling.md`
-- **Auth/middleware**: `hooks-lifecycle.md`, `encapsulation.md`
+- **Auth/middleware**: `authentication.md`, `hooks-lifecycle.md`, `encapsulation.md`
 - **Custom decorators**: `decorators.md`, `typescript-integration.md`
 - **Logging**: `logging.md`
 - **Writing tests**: `testing.md`, `create-server.md`