Composition seams

ELI5: Where two protocols plug together — the risky edges. The flywheel has four pillars; some repos are intentionally outside the loop.

In-scope flywheel seams

Seam	From → To	Mechanism
Fee ingress	Coil → CoilFeeRouter	USDC harvest
Keep funding	CoilFeeRouter → CoilMaker / vault	keep_bps deposit path
Surplus	CoilFeeRouter → TareEngine	Swap + donate
Surplus split	Engine → SurplusSplitter → sTARE + Keep	Skim
Governance	GaugeController → GaugeWeightRouter → Keep	set_allocations
Bribes	CoilFeeRouter → BribeDistributor	gauge_bps USDC
Market making	CoilMakerStrategy → Coil	EIP-1271 intents

flowchart TD
    subgraph inScope [In-scope four pillars]
        TARE[TARE]
        Keep[Keep]
        Coil[Coil]
        veForge[veForge]
    end
    Coil -->|fees| TARE
    Coil -->|keep_bps| Keep
    Coil -->|gauge_bps| veForge
    TARE -->|surplus split| Keep
    veForge -->|allocations| Keep
    Keep -->|CoilMaker| Coil

Out of scope (by design)

Repo	Reason
tribute/	Standalone payments — no Sepolia binding
SnekSentry/	Monitoring tooling — not value path
AGENTS_FLYWHEEL/	Read-only security agents

Known composition fixes

ID	Fix
COMP-2	ALLOCATOR_ROLE on vault — router cannot full manager
COMP-4	Document out-of-scope repos explicitly
FMR-002	CoilFeeRouter redeploy — correct keep deposit path

Verification tooling

• Composition auditor — AGENTS_FLYWHEEL/agents/security/composition_auditor/
• deploy_verifier — address drift vs manifests
• stresssim — adversarial economic scenarios

What can go wrong

Seam risks

• Bare USDC transfer to vault without deposit — does not credit total_idle (FLYWHEEL 2.0 addressed in router)
• Stale address in marketing HTML vs on-chain manifest
• Gauge epoch lag — votes apply weekly, not instantly

See internal review: reviews/composition-review-2026-06/