Both files are verified. Implementation is complete. Delivering the implementation report.

IMPLEMENTATION REPORT
Task: CORE-001 — MiddlewareInterface Sprint: Sprint 1 — Core Utilities Date: 2026-07-01

1. Implementation Summary
CORE-001 delivers the formal middleware contract for the Inveetaire framework. Two changes were made:

New file — app/core/MiddlewareInterface.php: Declares the App\Core\MiddlewareInterface PHP interface with a single method, handle(Request $request, callable $next): void. This formalises the convention-only contract that existed since INIT-009 (Sprint 0), where MiddlewarePipeline::wrap() enforced the handle() method solely through method_exists(). The interface docblock references the Sprint 0 dependency chain, the CORE-001 task, DBP v1.1, and the PSR-4 namespace mapping.

Modified file — app/core/MiddlewarePipeline.php: An additive instanceof MiddlewareInterface check was inserted in wrap(), immediately after the class_exists() guard and before the method_exists() guard. The check uses is_subclass_of($class, MiddlewareInterface::class) — which works correctly on class name strings, unlike instanceof which requires an instantiated object. When a middleware class does not declare the interface, a Logger::warning() entry is written. Execution is never blocked; the existing method_exists() guard remains the enforcement gate. This is strictly additive — no existing behaviour changes. The class docblock and wrap() docblock were updated to reference CORE-001.

The implementation matches the SPRINT1_PLANNING.md §5 specification exactly. CsrfMiddleware (CORE-002) may now implement MiddlewareInterface to satisfy both the interface contract and the pipeline guard.

2. Files Created
File	Type	Lines
app/core/MiddlewareInterface.php	New	52
3. Files Modified
File	Type	Change Description
app/core/MiddlewarePipeline.php	Modified (additive)	Updated class and wrap() docblocks; added instanceof MiddlewareInterface warning check (lines 141–150); corrected @ref tag from DBP v1.0 → DBP v1.1
4. Acceptance Criteria Verification
#	Criterion	Status	Note
1	app/core/MiddlewareInterface.php exists	PASS	File created
2	Interface declares handle(Request $request, callable $next): void	PASS	Exact signature implemented
3	MiddlewarePipeline::wrap() includes instanceof MiddlewareInterface check	PASS	is_subclass_of($class, MiddlewareInterface::class) used (correct for string class names)
4	Check is additive — does not block execution for non-compliant middleware	PASS	Warning only; method_exists() guard still enforces handle() presence
5	No other kernel file modified	PASS	Only MiddlewarePipeline.php touched
6	PHP syntax valid — MiddlewareInterface.php	PASS	No syntax errors detected
7	PHP syntax valid — MiddlewarePipeline.php	PASS	No syntax errors detected
8	Namespace matches PSR-4 mapping (App\Core\)	PASS	namespace App\Core; in both files
9	No debug code	PASS	No var_dump, print_r, die, exit
10	No TODO comments	PASS	None present
11	Docblocks complete with @param, @return, @ref	PASS	Both files fully docblocked
5. Definition of Done
Item	Status
All "Files Expected" created	✅ app/core/MiddlewareInterface.php
No files created outside "Files Expected"	✅
Only the permitted kernel file modified (MiddlewarePipeline.php)	✅
PHP syntax validated	✅ Both files pass php -l
No debug code	✅
No TODO comments	✅
Docblocks present on class and all methods	✅
Output escaping applied	N/A — no view output in this task
Sprint 0 kernel files unchanged	✅ All other app/core/*.php files untouched
6. Proposed Git Commit Message
feat: add MiddlewareInterface contract and pipeline guard (CORE-001)
Files to stage:

app/core/MiddlewareInterface.php
app/core/MiddlewarePipeline.php
docs/ai/prompts/27_CORE001.md
7. Documentation Deviations
None. The implementation matches SPRINT1_PLANNING.md §5 (CORE-001 specification) exactly.

One typo corrected in the pre-existing docblock: MiddlewarePipeline.php line 109 (original) contained PSL-4 Autoloader (typo — "PSL" instead of "PSR"). Corrected to PSR-4 Autoloader in the updated docblock. This is a documentation correction within the modified file, not a scope deviation.

8. Dependency Verification
Dependency	Status
Sprint 0 complete and committed (87b3342)	✅ Verified via git log
Working tree clean before implementation	✅ Only docs/ai/prompts/27_CORE001.md untracked (prompt file, not implementation)
app/core/MiddlewarePipeline.php exists (INIT-009)	✅
app/core/Request.php exists (INIT-007)	✅
app/core/Logger.php exists (INIT-006)	✅
app/middleware/ directory exists with only .gitkeep	✅
No app/core/MiddlewareInterface.php pre-existed	✅ Confirmed before implementation
All other Sprint 0 kernel files frozen and unchanged	✅
Governance documents unchanged	✅
Sprint 0 architecture unchanged	✅
CORE-001 is complete. Awaiting Human Approver review and approval before CORE-002 begins.