Document dependency reduction plan

Co-authored-by: Tuntii <121901995+Tuntii@users.noreply.github.com>

Author: Copilot

docs/PHILOSOPHY.md

@@ -105,6 +105,23 @@ validator = "0.16"
 2. We bump `rustapi-rs` to `0.2.0`
 3. **Your code stays exactly the same** — just update the version
 
+### External Dependency Reduction (Dış Bağımlılıkları Azaltma)
+
+RustAPI already hides external crates behind internal adapters. To reduce dependency debt, we focus on components with a stable spec and a small surface area, while keeping the public API unchanged. The playbook is:
+
+1. Wrap dependencies with internal traits/types so behavior is defined by RustAPI.
+2. Add contract tests to lock in behavior before replacing internals.
+3. Ship replacements behind feature flags, then flip defaults.
+
+Good candidates for in-house implementations:
+- Validation (`validator`) → native validation engine (already planned).
+- Router (`matchit`) → internal radix tree with RustAPI-specific optimizations.
+- OpenAPI (`utoipa`) → native schema generator to control outputs.
+- TOON format (`toon-format`) → move core format logic into `rustapi-toon`.
+- Template engine (`tera`) → minimal renderer for basic HTML views.
+
+Not near-term targets: `tokio`, `hyper`, `tower` — large, security-sensitive, and foundational crates best kept upstream for now.
+
 ### 4. 🎁 Batteries Included (But Optional)
 
 **Everything you need, nothing you don't.**

docs/README.md

@@ -28,6 +28,10 @@ RustAPI is an ergonomic web framework for Rust, inspired by FastAPI's developer
 
 RustAPI provides a stable, ergonomic public API. Internal dependencies (`hyper`, `tokio`, `validator`) are implementation details that can be upgraded without breaking your code.
 
+### External Dependency Plan
+
+To reduce external dependency debt (dış borç), we prioritize replacing crates with stable specs and small surfaces while keeping the public API unchanged. Candidate areas for RustAPI-owned implementations are validation, routing, OpenAPI generation, and the TOON format. Foundational runtime and HTTP crates (`tokio`, `hyper`, `tower`) remain external for stability and security.
+
 ## Getting Started
 
 ```toml