Rust CI Policy

This project uses a tiered Rust CI policy so parity coverage is predictable while CI remains stable.

Required Rust Jobs

The following jobs in .github/workflows/ci.yml are required gates:

• rust-parity-required
• rust-feed-parity-required

build depends on both required Rust jobs, so PRs cannot merge cleanly unless these lanes pass.

Required scope

rust-parity-required must:

• install/build the Rust extension in CI,
• run Python<->Rust engine parity suites in at least one required environment,
• fail on parity regressions.

Current required engine parity coverage includes:

• Rust bridge smoke tests,
• event normalization parity,
• sequencer parity,
• invariant parity,
• core parity fixtures,
• legal transition matrix parity,
• replay parity.

rust-feed-parity-required must:

• install/build the Rust extension in CI,
• run the feed parity gate (scripts/run_feed_rust_parity_gate.py) with benchmark checks,
• fail on feed parity or benchmark gate regressions.

Optional Rust Job

rust-parity-extended is non-blocking (continue-on-error: true).

It runs a heavier parity gate (including optional integration and benchmark checks) to surface issues early without blocking merges on occasional environment noise.

Local Skip/Fallback Policy

When the Rust extension is unavailable locally:

• Python<->Rust parity modules skip via runtime availability checks.
• Python-only suites remain runnable.
• Contributors can build the extension with:
• python scripts/install_rust_backend.py

Local skips are acceptable for development, but PRs must pass required Rust CI lanes before merge.