feat(unstable-v2): require v2 implementation info

agent-client-protocol-schema/src/v2/agent.rs

@@ -58,13 +58,8 @@ pub struct InitializeRequest {
     /// Capabilities supported by the client.
     #[serde(default)]
     pub capabilities: ClientCapabilities,
-    /// Information about the Client name and version sent to the Agent.
-    ///
-    /// Note: in future versions of the protocol, this will be required.
-    #[serde_as(deserialize_as = "DefaultOnError")]
-    #[schemars(extend("x-deserialize-default-on-error" = true))]
-    #[serde(default)]
-    pub client_info: Option<Implementation>,
+    /// Information about the implementation sending this initialize request.
+    pub info: Implementation,
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -77,11 +72,11 @@ pub struct InitializeRequest {
 impl InitializeRequest {
     /// Builds [`InitializeRequest`] with the required request fields set; optional fields start unset or empty.
     #[must_use]
-    pub fn new(protocol_version: ProtocolVersion) -> Self {
+    pub fn new(protocol_version: ProtocolVersion, info: Implementation) -> Self {
         Self {
             protocol_version,
             capabilities: ClientCapabilities::default(),
-            client_info: None,
+            info,
             meta: None,
         }
     }
@@ -93,13 +88,6 @@ impl InitializeRequest {
         self
     }
 
-    /// Information about the Client name and version sent to the Agent.
-    #[must_use]
-    pub fn client_info(mut self, client_info: impl IntoOption<Implementation>) -> Self {
-        self.client_info = client_info.into_option();
-        self
-    }
-
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -137,13 +125,8 @@ pub struct InitializeResponse {
     #[schemars(extend("x-deserialize-default-on-error" = true, "x-deserialize-skip-invalid-items" = true))]
     #[serde(default)]
     pub auth_methods: Vec<AuthMethod>,
-    /// Information about the Agent name and version sent to the Client.
-    ///
-    /// Note: in future versions of the protocol, this will be required.
-    #[serde_as(deserialize_as = "DefaultOnError")]
-    #[schemars(extend("x-deserialize-default-on-error" = true))]
-    #[serde(default)]
-    pub agent_info: Option<Implementation>,
+    /// Information about the implementation sending this initialize response.
+    pub info: Implementation,
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -156,12 +139,12 @@ pub struct InitializeResponse {
 impl InitializeResponse {
     /// Builds [`InitializeResponse`] with the required response fields set; optional fields start unset or empty.
     #[must_use]
-    pub fn new(protocol_version: ProtocolVersion) -> Self {
+    pub fn new(protocol_version: ProtocolVersion, info: Implementation) -> Self {
         Self {
             protocol_version,
             capabilities: AgentCapabilities::default(),
             auth_methods: vec![],
-            agent_info: None,
+            info,
             meta: None,
         }
     }
@@ -180,13 +163,6 @@ impl InitializeResponse {
         self
     }
 
-    /// Information about the Agent name and version sent to the Client.
-    #[must_use]
-    pub fn agent_info(mut self, agent_info: impl IntoOption<Implementation>) -> Self {
-        self.agent_info = agent_info.into_option();
-        self
-    }
-
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.

agent-client-protocol-schema/src/v2/conversion.rs

@@ -2697,13 +2697,13 @@ impl IntoV1 for super::InitializeRequest {
         let Self {
             protocol_version,
             capabilities,
-            client_info,
+            info,
             meta,
         } = self;
         Ok(crate::v1::InitializeRequest {
             protocol_version: protocol_version.into_v1()?,
             client_capabilities: capabilities.into_v1()?,
-            client_info: into_v1_default_on_error(client_info),
+            client_info: Some(info.into_v1()?),
             meta: meta.into_v1()?,
         })
     }
@@ -2719,10 +2719,18 @@ impl IntoV2 for crate::v1::InitializeRequest {
             client_info,
             meta,
         } = self;
+        let info = match client_info {
+            Some(client_info) => client_info.into_v2()?,
+            None => {
+                return Err(ProtocolConversionError::new(
+                    "v1 InitializeRequest without `clientInfo` cannot be represented in v2",
+                ));
+            }
+        };
         Ok(super::InitializeRequest {
             protocol_version: protocol_version.into_v2()?,
             capabilities: client_capabilities.into_v2()?,
-            client_info: into_v2_default_on_error(client_info),
+            info,
             meta: meta.into_v2()?,
         })
     }
@@ -2736,14 +2744,14 @@ impl IntoV1 for super::InitializeResponse {
             protocol_version,
             capabilities: agent_capabilities,
             auth_methods,
-            agent_info,
+            info,
             meta,
         } = self;
         Ok(crate::v1::InitializeResponse {
             protocol_version: protocol_version.into_v1()?,
             agent_capabilities: agent_capabilities.into_v1()?,
             auth_methods: into_v1_vec_skip_errors(auth_methods),
-            agent_info: into_v1_default_on_error(agent_info),
+            agent_info: Some(info.into_v1()?),
             meta: meta.into_v1()?,
         })
     }
@@ -2760,11 +2768,19 @@ impl IntoV2 for crate::v1::InitializeResponse {
             agent_info,
             meta,
         } = self;
+        let info = match agent_info {
+            Some(agent_info) => agent_info.into_v2()?,
+            None => {
+                return Err(ProtocolConversionError::new(
+                    "v1 InitializeResponse without `agentInfo` cannot be represented in v2",
+                ));
+            }
+        };
         Ok(super::InitializeResponse {
             protocol_version: protocol_version.into_v2()?,
             capabilities: agent_capabilities.into_v2()?,
             auth_methods: into_v2_vec_skip_errors(auth_methods),
-            agent_info: into_v2_default_on_error(agent_info),
+            info,
             meta: meta.into_v2()?,
         })
     }
@@ -9049,20 +9065,41 @@ mod tests {
 
     #[test]
     fn converts_v2_initialize_request_to_v1_without_serde() {
-        let request = v2::InitializeRequest::new(ProtocolVersion::V2);
+        let request = v2::InitializeRequest::new(
+            ProtocolVersion::V2,
+            v2::Implementation::new("test-client", "1.0.0"),
+        );
 
         let converted: v1::InitializeRequest = v2_to_v1(request).unwrap();
 
         assert_eq!(converted.protocol_version, ProtocolVersion::V2);
+        assert_eq!(
+            converted
+                .client_info
+                .as_ref()
+                .map(|info| info.name.as_str()),
+            Some("test-client")
+        );
     }
 
     #[test]
-    fn converts_v1_initialize_request_to_v2_without_serde() {
+    fn v1_initialize_request_without_client_info_does_not_convert_to_v2() {
         let request = v1::InitializeRequest::new(ProtocolVersion::V1);
 
-        let converted: v2::InitializeRequest = v1_to_v2(request).unwrap();
+        assert_v1_to_v2_error(
+            request,
+            "v1 InitializeRequest without `clientInfo` cannot be represented in v2",
+        );
+    }
+
+    #[test]
+    fn v1_initialize_response_without_agent_info_does_not_convert_to_v2() {
+        let response = v1::InitializeResponse::new(ProtocolVersion::V1);
 
-        assert_eq!(converted.protocol_version, ProtocolVersion::V1);
+        assert_v1_to_v2_error(
+            response,
+            "v1 InitializeResponse without `agentInfo` cannot be represented in v2",
+        );
     }
 
     #[test]
@@ -9086,9 +9123,13 @@ mod tests {
         let converted: v2::InitializeRequest =
             v1_to_v2(request).expect("v1 -> v2 conversion failed");
         let converted_capabilities =
-            serde_json::to_value(converted.capabilities).expect("v2 serialize");
+            serde_json::to_value(&converted.capabilities).expect("v2 serialize");
         assert_eq!(converted_capabilities.get("fs"), None);
         assert_eq!(converted_capabilities.get("terminal"), None);
+        let converted_json = serde_json::to_value(&converted).expect("v2 serialize");
+        assert_eq!(converted_json.get("clientInfo"), None);
+        assert_eq!(converted_json.get("implementation"), None);
+        assert!(converted_json.get("info").is_some());
     }
 
     #[test]
@@ -9101,6 +9142,9 @@ mod tests {
         let converted_json = serde_json::to_value(&converted).expect("v2 serialize");
         assert_eq!(converted_json.get("agentCapabilities"), None);
         assert!(converted_json.get("capabilities").is_some());
+        assert_eq!(converted_json.get("agentInfo"), None);
+        assert_eq!(converted_json.get("implementation"), None);
+        assert!(converted_json.get("info").is_some());
         assert_eq!(converted_json.pointer("/capabilities/loadSession"), None);
     }
 
@@ -9918,17 +9962,20 @@ mod tests {
 
     #[test]
     fn v2_collection_conversion_skips_items_like_v1_vec_skip_error() {
-        let response = v2::InitializeResponse::new(ProtocolVersion::V2)
-            .capabilities(v2::AgentCapabilities::new().session(v2::SessionCapabilities::new()))
-            .auth_methods(vec![
-                v2::AuthMethod::Other(v2::OtherAuthMethod::new(
-                    "_oauth",
-                    "oauth",
-                    "OAuth",
-                    BTreeMap::default(),
-                )),
-                v2::AuthMethod::Agent(v2::AuthMethodAgent::new("agent", "Agent")),
-            ]);
+        let response = v2::InitializeResponse::new(
+            ProtocolVersion::V2,
+            v2::Implementation::new("test-agent", "2.0.0"),
+        )
+        .capabilities(v2::AgentCapabilities::new().session(v2::SessionCapabilities::new()))
+        .auth_methods(vec![
+            v2::AuthMethod::Other(v2::OtherAuthMethod::new(
+                "_oauth",
+                "oauth",
+                "OAuth",
+                BTreeMap::default(),
+            )),
+            v2::AuthMethod::Agent(v2::AuthMethodAgent::new("agent", "Agent")),
+        ]);
         let converted: v1::InitializeResponse = v2_to_v1(response).unwrap();
         assert_eq!(converted.auth_methods.len(), 1);
         assert!(matches!(

docs/protocol/v2/draft/initialization.mdx

@@ -27,8 +27,7 @@ Before a Session can be created, Clients **MUST** initialize the connection by c
 
 - The latest [protocol version](#protocol-version) supported
 - The [capabilities](#client-capabilities) supported
-
-They **SHOULD** also provide a name and version to the Agent.
+- The [implementation information](#implementation-information) for the Client
 
 ```json
 {
@@ -38,7 +37,7 @@ They **SHOULD** also provide a name and version to the Agent.
   "params": {
     "protocolVersion": 2,
     "capabilities": {},
-    "clientInfo": {
+    "info": {
       "name": "my-client",
       "title": "My Client",
       "version": "1.0.0"
@@ -47,7 +46,7 @@ They **SHOULD** also provide a name and version to the Agent.
 }
 ```
 
-The Agent **MUST** respond with the chosen [protocol version](#protocol-version) and the [capabilities](#agent-capabilities) it supports. It **SHOULD** also provide a name and version to the Client as well:
+The Agent **MUST** respond with the chosen [protocol version](#protocol-version), the [capabilities](#agent-capabilities) it supports, and its [implementation information](#implementation-information):
 
 ```json
 {
@@ -69,7 +68,7 @@ The Agent **MUST** respond with the chosen [protocol version](#protocol-version)
         "load": {}
       }
     },
-    "agentInfo": {
+    "info": {
       "name": "my-agent",
       "title": "My Agent",
       "version": "1.0.0"
@@ -230,7 +229,7 @@ Optionally, they **MAY** support richer types of [content](/protocol/v2/draft/co
 
 ## Implementation Information
 
-Both Clients and Agents **SHOULD** provide information about their implementation in the `clientInfo` and `agentInfo` fields respectively. Both take the following three fields:
+Both Clients and Agents **MUST** provide information about their implementation in the `info` field. It takes the following three fields:
 
 <ParamField path="name" type="string">
   Intended for programmatic or logical use, but can be used as a display name
@@ -247,10 +246,6 @@ Both Clients and Agents **SHOULD** provide information about their implementatio
   debugging or metrics purposes.
 </ParamField>
 
-<Info>
-  Note: in future versions of the protocol, this information will be required.
-</Info>
-
 ---
 
 Once the connection is initialized, you're ready to [create a session](/protocol/v2/draft/session-setup) and begin the conversation with the Agent.

docs/protocol/v2/draft/schema.mdx

@@ -282,11 +282,8 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v2/d
     - Default: `{"auth":{}}`
 
 </ResponseField>
-<ResponseField name="clientInfo" type={<><span><a href="#implementation">Implementation</a></span><span> | null</span></>} >
-  Information about the Client name and version sent to the Agent.
-
-Note: in future versions of the protocol, this will be required.
-
+<ResponseField name="info" type={<a href="#implementation">Implementation</a>} required>
+  Information about the implementation sending this initialize request.
 </ResponseField>
 <ResponseField name="protocolVersion" type={<a href="#protocolversion">ProtocolVersion</a>} required>
   The latest protocol version supported by the client.
@@ -311,12 +308,6 @@ these keys.
 
 See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v2/draft/extensibility)
 
-</ResponseField>
-<ResponseField name="agentInfo" type={<><span><a href="#implementation">Implementation</a></span><span> | null</span></>} >
-  Information about the Agent name and version sent to the Client.
-
-Note: in future versions of the protocol, this will be required.
-
 </ResponseField>
 <ResponseField name="authMethods" type={<a href="#authmethod">AuthMethod[]</a>} >
   Authentication methods supported by the agent.
@@ -330,6 +321,9 @@ Note: in future versions of the protocol, this will be required.
     - Default: `{"auth":{}}`
 
 </ResponseField>
+<ResponseField name="info" type={<a href="#implementation">Implementation</a>} required>
+  Information about the implementation sending this initialize response.
+</ResponseField>
 <ResponseField name="protocolVersion" type={<a href="#protocolversion">ProtocolVersion</a>} required>
   The protocol version the client specified if supported by the agent,
 or the latest protocol version supported by the agent.