Implementation complete. Delivering the report.

IMPLEMENTATION REPORT
Task: CORE-002 — CsrfMiddleware Sprint: Sprint 1 — Core Utilities Date: 2026-07-01

1. Implementation Summary
CORE-002 delivers the CSRF protection middleware for the Inveetaire framework. One new file was created. No existing files were modified.

app/middleware/CsrfMiddleware.php implements App\Core\MiddlewareInterface and integrates the Sprint 0 CSRF infrastructure into the middleware pipeline in a single, focused handle() method:

Csrf::validate($request) is called unconditionally. For non-POST methods (GET, HEAD, OPTIONS), Csrf::validate() returns true transparently — the bypass logic lives in Csrf, not in this middleware, keeping the middleware single-purpose and free of branching on HTTP method.
On validation failure: Logger::warning() records the method and path, then ErrorHandler::renderForbidden() renders the 403 response. $next is not called — the pipeline terminates.
On validation success: $next($request) is called, continuing the pipeline to the next layer or controller action.
The middleware has zero coupling to authentication, sessions (beyond what Csrf::validate() already accesses), controllers, models, or services. CSRF exemptions are handled per-route by simply omitting CsrfMiddleware from a route's middleware list — no bypass logic within this class.

Correction found during implementation: The initial Logger call used $request->method() and $request->uri() — methods that do not exist on Request. The correct methods are getMethod() and getPath(). The file was corrected before syntax validation was run.

2. Files Created
File	Type	Lines
app/middleware/CsrfMiddleware.php	New	85
3. Files Modified
None.

4. Acceptance Criteria Verification
#	Criterion	Status	Note
1	app/middleware/CsrfMiddleware.php exists	PASS	File created
2	Class implements App\Core\MiddlewareInterface	PASS	class CsrfMiddleware implements MiddlewareInterface
3	handle(Request $request, callable $next): void declared	PASS	Exact signature matches interface
4	POST with valid CSRF token → $next($request) called	PASS	Csrf::validate() returns true → $next($request)
5	POST with missing/invalid token → 403, $next NOT called	PASS	ErrorHandler::renderForbidden() + return before $next
6	Non-POST requests pass through unconditionally	PASS	Csrf::validate() returns true for non-POST; $next($request) called
7	ErrorHandler::renderForbidden() used (no raw output)	PASS	No echo, no header() in middleware
8	Logger::warning() called on CSRF failure	PASS	Logs method and path
9	No authentication, authorization, or session logic	PASS	Only Csrf::validate(), Logger::warning(), ErrorHandler::renderForbidden()
10	No Controller, Model, or Service dependency	PASS	All dependencies are Sprint 0 kernel classes
11	Namespace App\Middleware\ — PSR-4 mapping app/middleware/	PASS	
12	PHP syntax valid	PASS	No syntax errors detected
13	No debug code	PASS	No var_dump, print_r, die, exit
14	No TODO comments	PASS	None present
15	Docblock complete with @param, @return, @ref	PASS	Class and method fully docblocked
5. Definition of Done
Item	Status
All "Files Expected" created	✅ app/middleware/CsrfMiddleware.php
No files created outside "Files Expected"	✅
No kernel files modified	✅ Zero kernel files touched
PHP syntax validated	✅ Passes php -l
No debug code	✅
No TODO comments	✅
Docblocks present on class and all methods	✅
Output escaping applied	N/A — no view output produced by this middleware
CORE-001 dependency satisfied before implementation	✅ f50f73f committed
6. Proposed Git Commit Message
feat: implement CsrfMiddleware (CORE-002)
Files to stage:

app/middleware/CsrfMiddleware.php
docs/ai/memory/21_core001.md
docs/ai/prompts/28_CORE002.md
Note: app/middleware/.gitkeep removal — per SPRINT1_PLANNING.md §6, .gitkeep becomes redundant when CsrfMiddleware.php is created. Recommend staging git rm app/middleware/.gitkeep as part of this commit. This is documented in OBS-04 of the Sprint 1 Planning document. Awaiting Human Approver decision.

7. Documentation Deviations
One method name correction: During implementation, $request->method() and $request->uri() were used in the initial Logger call. Review of Request.php confirmed the correct method names are getMethod() and getPath(). Corrected before the file was finalized.

This is not a documentation deviation — the specification in SPRINT1_PLANNING.md §5 does not prescribe the Logger context keys. The correction was made by reading the actual dependency file (as required), not by deviating from any approved requirement.

8. Dependency Verification
Dependency	Status
CORE-001 committed (f50f73f — MiddlewareInterface exists)	✅
app/core/MiddlewareInterface.php — interface contract	✅
app/core/Csrf.php — validate(Request): bool (INIT-010)	✅
app/core/ErrorHandler.php — renderForbidden(): void (INIT-006)	✅
app/core/Logger.php — warning(string, array): void (INIT-006)	✅
app/core/Request.php — getMethod(), getPath(), isPost() (INIT-007)	✅
Sprint 0 framework remains frozen	✅ Zero Sprint 0 files modified
Governance unchanged	✅
No stub files created for future middleware	✅ app/middleware/ contains only CsrfMiddleware.php + .gitkeep
CORE-002 is complete. Awaiting Human Approver review and approval before CORE-003 begins.