What MPC solves — and what it does not
Multi-party computation can remove the single raw private-key boundary by distributing signing material/participation. It does not decide whether a transaction should happen, whether the destination is allowed, whether an amount exceeds business limits or whether the product ledger should be updated. Those remain application responsibilities.
Production integration boundary
A robust MPC integration has at least four independent layers: business authorization → signing request → blockchain execution → business posting. A successful signature is evidence that the signing system approved an operation. It is not evidence that the business process is complete.
Policy before signing
Evaluate actor, role, transaction intent, asset, network, amount, destination, velocity limits and required approvals. Treasury flows often need multi-person approval or provider-side policy engines; programmatic wallet products may require application-side policy before calling their signing API.
Idempotency and correlation
Every signing request should have a stable business operation ID. Persist provider request IDs, transaction hashes and status transitions. Retrying an API timeout must not create a second withdrawal.
Recovery and key rotation
Design recovery for user access, operator access, entity secrets, signer changes and provider migration. Recovery should be rehearsed, documented and separated from normal transaction privileges.
Provider selection questions
- Who controls each signing share or credential?
- Can signing be executed server-side?
- Which approval policies exist natively?
- How is recovery performed?
- How are audit events exported?
- What happens during partial service outage?
- How are EVM and non-EVM accounts represented?
- Can the application retain a provider-neutral wallet registry?
MPC does not replace the ledger
Even perfect signing infrastructure cannot tell finance why money moved. Keep wallet execution references attached to a product-owned ledger and reconciliation timeline.
Implementation pattern
Transaction Intent → Authorization Policy → Approval(s) → MPC/Signing API → Broadcast → Chain Observation → Finality → Ledger Posting → Reconciliation.
This order creates clear failure boundaries and allows a support/operator team to answer where a transaction stopped.