Clean up RFD

Author: benbrandt

docs/rfds/custom-llm-endpoint.mdx

@@ -102,8 +102,23 @@ If `providers` is absent, clients must treat provider methods as unsupported.
 ### Types
 
 ```typescript
-/** Well-known API protocol identifiers. */
-type LlmProtocol = "anthropic" | "openai" | "azure" | "vertex" | "bedrock";
+/**
+ * Well-known API protocol identifiers for LLM providers.
+ *
+ * This is an open string type: agents and clients MUST handle unknown
+ * protocol identifiers gracefully.
+ *
+ * Protocol names beginning with `_` are free for custom use, like other
+ * ACP extension methods. Protocol names that do not begin with `_` are
+ * reserved for the ACP spec.
+ */
+type LlmProtocol =
+  | "anthropic"
+  | "openai"
+  | "azure"
+  | "vertex"
+  | "bedrock"
+  | string;
 
 interface ProviderCurrentConfig {
   /** Protocol currently used by this provider. */
@@ -172,8 +187,9 @@ interface ProvidersSetRequest {
   /**
    * Full headers map for this provider.
    * May include authorization, routing, or other integration-specific headers.
+   * Omitting this field is equivalent to an empty map (no headers).
    */
-  headers: Record<string, string>;
+  headers?: Record<string, string>;
 
   /** Extension metadata */
   _meta?: Record<string, unknown>;
@@ -321,7 +337,7 @@ interface ProvidersDisableResponse {
 3. **List semantics**: `providers/list` returns configurable providers, their supported protocol types, current effective routing, and `required` flag. Providers SHOULD remain discoverable in list after `providers/disable`.
 4. **Client behavior for required providers**: clients SHOULD NOT call `providers/disable` for providers where `required: true`.
 5. **Disabled state encoding**: in `providers/list`, `current: null` means the provider is disabled and MUST NOT be used by the agent for LLM calls.
-6. **Set semantics and validation**: `providers/set` replaces the full configuration for the target `id` (`apiType`, `baseUrl`, full `headers`). If `id` is unknown, `apiType` is unsupported for that provider, or params are malformed, agents SHOULD return `invalid_params`.
+6. **Set semantics and validation**: `providers/set` replaces the full configuration for the target `id` (`apiType`, `baseUrl`, `headers`); an omitted `headers` field is treated as an empty map. If `id` is unknown, `apiType` is unsupported for that provider, or params are malformed, agents SHOULD return `invalid_params`.
 7. **Disable semantics**: `providers/disable` disables the target provider at runtime. A disabled provider MUST appear in `providers/list` with `current: null`. If target provider has `required: true`, agents MUST return `invalid_params`. Disabling an unknown `id` SHOULD be treated as success (idempotent behavior).
 8. **Scope and persistence**: provider configuration is process-scoped and SHOULD NOT be persisted to disk.
 

src/agent.rs

@@ -3593,7 +3593,7 @@ impl ListProvidersResponse {
 ///
 /// Replaces the full configuration for one provider id.
 #[cfg(feature = "unstable_llm_providers")]
-#[derive(Clone, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
 #[schemars(extend("x-side" = "agent", "x-method" = PROVIDERS_SET_METHOD_NAME))]
 #[serde(rename_all = "camelCase")]
 #[non_exhaustive]
@@ -3617,26 +3617,6 @@ pub struct SetProvidersRequest {
     pub meta: Option<Meta>,
 }
 
-#[cfg(feature = "unstable_llm_providers")]
-impl std::fmt::Debug for SetProvidersRequest {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("SetProvidersRequest")
-            .field("id", &self.id)
-            .field("api_type", &self.api_type)
-            .field("base_url", &self.base_url)
-            .field(
-                "headers",
-                &self
-                    .headers
-                    .keys()
-                    .map(|k| (k.as_str(), "[REDACTED]"))
-                    .collect::<Vec<_>>(),
-            )
-            .field("meta", &self.meta)
-            .finish()
-    }
-}
-
 #[cfg(feature = "unstable_llm_providers")]
 impl SetProvidersRequest {
     #[must_use]