Last updated Jun 14, 2026

MFN cascade (SEV2)

Triggered by: an MFN-bearing convertible's terms were improved strictly (lower cap OR higher discount OR lower interest, none worse), triggering propagation to siblings (apps/api/lib/convertible-amend.ts). The cascade saga executes per-sibling; partial failure is the alert condition.

On-call: Primary (cap-table bounded context). Estimated MTTR: 30-90 minutes.

Stop-the-bleed

1. Freeze new MFN-bearing convertibles in the affected entity:

   matter ops freeze-convertibles --entity-id <id> --reason "mfn cascade in flight"

2. Snapshot the affected convertibles + amendments:

   matter ops snapshot-cascade --cascade-id <id>

Diagnose

Per-sibling cascade state is in saga_instance rows. Check:

• Which siblings completed?
• Which failed and why?
• Are any in a compensating state?

matter ops mfn-cascade-status --cascade-id <id>

Failure modes:

Mode A: Counterparty consent missing

The cascade tried to amend a sibling whose counterparty consent wasn't pre-collected. Resolution: collect consent, resume.

Mode B: Fresh-409A drift

A sibling's cap reduction needs fresh 409A but the available valuation expired mid-cascade. Resolution: re-run valuation, resume.

Mode C: Concurrent amend race

Another amend operation on the same convertible raced with the cascade. Optimistic-concurrency conflict at the cascade step. Resolution: retry the failed leg.

Recover

matter ops mfn-cascade-resume --cascade-id <id>

The saga primitive's decideResume (P5.4) determines whether to retry vs compensate. Per packages/saga/close-package.tla — non-compensable steps halt; compensable retry.

Validate

matter ops verify-mfn-cascade --entity-id <id>

Expected: every MFN-bearing convertible's terms ≥ the triggering amendment's terms. The isMfnTriggered check should now return false for the cascade trigger.

Post-recovery action items

1. Add property test for the failed mode using apps/api/lib/saga-property.ts harness.
2. Update convertible-amend.ts admissibility if a missing gate caused the failure.