| name | ironclaw-reborn-architecture-review |
| description | Use when writing or reviewing a change in crates/ that adds a trait, a crate, a dependency edge, a re-export, or code in ironclaw_composition — or when deciding whether an abstraction, layer, or crate boundary is justified in the IronClaw Reborn stack. |
Reborn Architecture Review
Layer discipline here is enforced by machines, not vibes: cargo test -p ironclaw_architecture_tests (94 tests across 19 files; recount with cat crates/app/ironclaw_architecture_tests/tests/*.rs | grep -cE '^\s*#\[(test|tokio::test)') and the per-crate contract tests are the real reviewers. Your job is the failures machines can't see: mass pooling inside a crate and speculative abstraction.
Checklist (run all six; each is checkable)
- New trait? Demand the second implementation. A trait with one production impl is a ritual, not a boundary. Before accepting it, name the concrete second impl (a real backend, not a test fake) or the enforced boundary it serves (e.g. it keeps a forbidden dep out of a crate — verifiable in Cargo.toml). "So we can swap formatters later" / "so callers can hold
Arc<dyn …>" is the exact rationalization to reject — later can add the trait when later arrives; extraction from a concrete type is mechanical. Justified counter-examples to copy: RootFilesystem, PolicySource, LlmProvider (35 impls), and dependency-inversion ports whose impl must live up-layer (SkillInferencePort, CapabilityDispatcher). Unjustified precedent to not repeat: the ironclaw_memory contract crate as originally split (it now has two providers — ironclaw_memory_native and ironclaw_memory_mem0 — so the trait earns its keep; still on audit watch).
- New code in
ironclaw_composition? Prove it's assembly. The crate's charter is service-graph wiring. If your change adds behavior — delivery logic, auth flows, a domain service, a serve surface — it belongs in an owning crate; the host-side-of-a-product role is a real crate (ironclaw_webui is the model). Composition gets the build_*/with_* wiring only.
- New dependency edge? Check both the rules and their shape. Run
cargo test -p ironclaw_architecture_tests. Know its blind spots: most rules are blocklists, so a new crate is unruled by default — if you add a crate, add its boundary rule in the same PR (crates/app/ironclaw_architecture_tests/tests/reborn_dependency_boundaries.rs, boundary_rules()); the v1-only enclave those rules used to guard against (ironclaw_engine, ironclaw_tui, ironclaw_gateway, ironclaw_oauth) has been deleted, so every crate you can depend on is Reborn.
- New
pub use? Name the downstream consumer and the test that closes the direct path. The house pattern: composition's re-exports each carry a doc-comment citing consumer + boundary test. No glob re-exports of another crate at a crate root (the one sanctioned wildcard shape left is ironclaw_trace_commons' re-namespaced modules — ironclaw_host_api deliberately has no flat prelude any more; see the comment at crates/contracts/ironclaw_host_api/src/lib.rs).
- New public surface? Copy the visibility kit:
#![warn(unreachable_pub)], pub(crate) internals, sealed traits for strategy slots (ironclaw_agent_loop/src/planner.rs:15-26 is the template), directory-of-modules lib.rs (no re-export wall — a boundary test enforces this for internal crates).
- File growing past 1,500 lines (3,000 = tracking issue)? The rule is real (
.claude/rules/architecture.md §5), but verify whether the pre-commit check exists before relying on it: grep -n 'ARCH-SPRAWL' scripts/pre-commit-safety.sh. Same for #[allow(clippy::too_many_arguments)]: require an // arch-exempt: …, plan #NNNN line above it; don't add bare allows.
Rationalizations vs reality
| Rationalization | Reality |
|---|
| "Trait now, so we can swap later" | One impl = ritual. Add the trait with the second impl; extracting it later is mechanical. |
| "Composition already has similar code, I'll put it next to that" | Existing behavior-heavy code there is composition debt, not precedent. Precedent-by-pollution isn't placement. |
| "The boundary tests passed, so the architecture is fine" | They police edges, not interior mass or abstraction quality — the two ways this codebase actually decays. |
| "It's just a convenience re-export" | Every legitimate re-export here names its consumer and its enforcing test. No test, no re-export. |
| "This crate is in crates/, so it's current architecture" | It is — the v1-only enclave (ironclaw_engine/tui/gateway/oauth) has been deleted. The live risk is now the opposite: guidance still routing you around crates that no longer exist. Check reverse-deps before building on any crate. |
Verify
cargo test -p ironclaw_architecture_tests · cargo clippy -p <crate> --all-targets --all-features -- -D warnings · if routes changed: cargo test -p ironclaw_webui --test webui_v2_descriptors_contract.
Worked good/bad examples (before/after shapes, live exemplars, re-verify commands): references/worked-examples.md — the living curriculum; update it as the code evolves.
