* Permit.io provides several mechanisms to ensure consistency between policy decisions and underlying data: *Strong Consistency via "Send Consistent Updates" (Read-Your-Own-Writes) * Permit offers a feature called ​*Local Facts*​ that routes data changes through the PDP and waits for them to be applied before responding. (1) This ensures that when you create or update data (e.g., a user or role assignment) , subsequent permission checks immediately reflect that change. (2) For example, with

proxy_facts_via_pdp

enabled, the API call waits until the data is fully synced to the PDP before returning. (1) ​*Configuration Options:*​ • `timeout`: Controls how long to wait for data synchronization (0 = no waiting, positive value = wait up to N seconds, negative = wait indefinitely) • `timeout_policy`: Defines behavior on timeout—either

ignore

(respond immediately) or

fail

(return 424 status code) ​*Consistency Guarantees Available:*​ Permit provides fine-tuned consistency options: (3) • ​*Eventual consistency*​ (PDP updates within ~100ms on P95) • ​*Fully consistent updates*​ for mission-critical policies • ​*Health-check-based consistency with callbacks*​ for dynamic environments ​*Regarding Zanzibar-style Tokens:*​ While Permit doesn't use zookie tokens specifically, the Permit Cloud itself is described as a "Google Zanzibar equivalent" (4) , and the Local Facts / Send Consistent Updates feature provides similar guarantees by ensuring the PDP has the latest data before returning from write operations. (2) ​*Offline Mode:*​ For disconnected scenarios, Permit's PDP supports ​*Offline Mode*​, allowing it to operate without a live connection to the cloud—retrieving configuration once and continuing autonomously, even after restarts.

To learn more, see the sources I considered: [[1] Send Consistent Updates (Read-Your-Own-Writes)](https://docs.permit.io/how-to/manage-data/local-facts-uploader) [[2] Permit.io Launch Week - Day 5: Fine-Tuned Performance](https://www.permit.io/blog/launch-week-5-performance) [[3] Permit Strength Points](https://docs.permit.io/concepts/differentiator-checklist) [[4] Integration with Google Zanzibar inspired Authorization Frameworks like OpenFGA, SpiceDB, Ory Keto](https://github.com/permitio/opal/discussions/633)