# `AshPhoenixGenApi.Verifiers.VerifyDomainConfig`
[🔗](https://github.com/ohhi-vn/ash_phoenix_gen_api/blob/v1.0.3/lib/ash_phoenix_gen_api/verifiers/verify_domain_config.ex#L1)

Verifier for the `gen_api` section of `AshPhoenixGenApi.Domain`.

This verifier performs compile-time validation of the PhoenixGenApi domain-level
configuration. It checks:

1. **Supporter module name** — The `supporter_module` must be a valid Elixir
   module name (atom).

2. **Service configuration** — When `define_supporter?` is `true`, the `service`
   must be configured.

3. **Resource consistency** — All resources in the domain that have the
   `AshPhoenixGenApi.Resource` extension must also have a `service` configured
   in their `gen_api` section. If a resource doesn't have its own `service`,
   the domain's `service` will be used as a fallback, so the domain must have
   one in that case.

4. **Request type uniqueness across resources** — No two resources in the
   domain may expose the same `request_type` string. This prevents routing
   conflicts on the gateway node.

5. **Supporter module not already defined** — When `define_supporter?` is
   `true`, warns if the supporter module already exists (which could indicate
   a conflict with a manually-defined module).

6. **Push nodes configuration** — When `push_nodes` is configured, validates
   that it is either a list of atom node names, an MFA tuple
   `{module, function, args}`, `:local`, or `nil`. Lists must contain only
   atoms, and MFA tuples must have the correct structure.

7. **Permission callback configuration** — When `permission_callback` is
   configured, validates that it is either a valid MFA tuple
   `{module, function, args}` or `nil`. MFA tuples must have the correct
   structure (module and function must be atoms, args must be a list).

## Error Messages

The verifier raises `Spark.Error.DslError` with descriptive messages
and the path to the offending configuration.

---

*Consult [api-reference.md](api-reference.md) for complete listing*