# Atomic-tx invariant (/sdk/atomic-tx-invariant)



`In progress`

AgentTrust treats a policy check as useful only when the facilitator enforces the same payment context through settlement. The SDK keeps that invariant explicit in config and tests.

| Source              | Path                                                                                                                                     |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| SDK invariant guard | [`trustgate/sdk/src/atomicity.ts`](https://github.com/agenttrust-labs/agenttrust/blob/main/trustgate/sdk/src/atomicity.ts)               |
| tests               | [`trustgate/sdk/test/atomicity.test.ts`](https://github.com/agenttrust-labs/agenttrust/blob/main/trustgate/sdk/test/atomicity.test.ts)   |
| facilitator routes  | [`trustgate/server/src/routes/settle.ts`](https://github.com/agenttrust-labs/agenttrust/blob/main/trustgate/server/src/routes/settle.ts) |