Bindings
A binding is the routing rule: it joins a signal filter (which events?) to a deliverable type (what payload shape?) to a destination (ship where?) via a serializer (encoded how?). On create, the backend validates all four pieces form a compatible triangle — the serializer must support the resolver's shape, and the connector must support the serializer format.
Optional field_map (rename/drop/static rules) lets you reshape the payload without custom code. Optional delivery_policy overrides the default retry ladder (6 attempts at 5s, 30s, 2min, 10min, 1h) and timeout.