Security engineering

Secure and reliable by default

Defendy processes production events with explicit contracts, idempotency, backpressure and observability.

Event-driven contracts

Versioned NATS JetStream events and explicit ConsumerConfig.

Nats-Msg-Id, Redis dedupe and unique constraints prevent duplicate processing.

Pending limits, timeouts and retries only for transient failures.

Secrets stay outside Git; Telegram initData and administrator rights are validated.

Structured logs, correlation IDs, health checks and runbooks.

Feature flags, shadow mode, canaries and fast rollback.

Event path

01Telegram eventmember join or message

02Policy checkthe group's enabled rules

03Actiondelete, warn or restrict

04Log chatreason and applied policy

Permissions in the default add link

Delete messagescore filters

Restrict memberscaptcha and penalties

Ban usersviolation escalation

Pin messagesmanagement workflows

Some workflows, including topics and invite-link management, require additional permissions.