# `GRPC.Client.ServiceConfig`
[🔗](https://github.com/elixir-grpc/grpc/tree/master/grpc/blob/v1.0.1/lib/grpc/client/service_config.ex#L1)

Represents the gRPC `ServiceConfig` parsed from JSON, which can come from DNS TXT records or xDS.

The gRPC `ServiceConfig` allows a client to configure per-service and per-method
behaviors such as load balancing, timeouts, and retry policies.

## Spec

According to the gRPC specification ([service_config.md](https://github.com/grpc/grpc/blob/master/doc/service_config.md)):

- loadBalancingConfig: a list of load balancing policies.
  The client should pick the first policy it supports. Common values are:
    - `"pick_first"`: always pick the first server.
    - `"round_robin"`: distribute calls across servers in round-robin.

- methodConfig: a list of configurations applied to specific methods or services.
  Each entry can include:
    - `"name"`: a list of `{ "service": "<service_name>", "method": "<method_name>" }`
      or `{ "service": "<service_name>" }` to match all methods in the service.
    - `"timeout"`: RPC timeout as a string (e.g., `"1.000000001s"`).
    - `"retryPolicy"`: optional retry policy map.
    - Other optional method-level settings.

## Example TXT record

A DNS TXT record for a service `my-service.local` might look like this:

    _grpc_config.my-service.local 3600 TXT
    "grpc_config={
      "loadBalancingConfig":[{"round_robin":{}}],
      "methodConfig":[
        {
          "name":[
            {"service":"foo","method":"bar"},
            {"service":"baz"}
          ],
          "timeout":"1.000000001s"
        }
      ]
    }"

This JSON will be parsed into a `%GRPC.Client.ServiceConfig{}` struct with:

    %GRPC.Client.ServiceConfig{
      load_balancing_policy: :round_robin,
      method_configs: [
        %{
          "name" => [
            %{"service" => "foo", "method" => "bar"},
            %{"service" => "baz"}
          ],
          "timeout" => "1.000000001s"
        }
      ],
      raw: <original JSON map>
    }

## Usage

```elixir
{:ok, config} = GRPC.Client.ServiceConfig.parse(txt_json)
IO.inspect(config.load_balancing_policy)
IO.inspect(config.method_configs)
```

# `t`

```elixir
@type t() :: %GRPC.Client.ServiceConfig{
  load_balancing_policy: atom(),
  method_configs: list(),
  raw: map()
}
```

# `parse`

---

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