From 1023acf69f2577395d3e7d6ecd104160e6516fc3 Mon Sep 17 00:00:00 2001
From: damocles <damocles@hyperhive>
Date: Sat, 16 May 2026 20:28:42 +0200
Subject: [PATCH] add get_logs tool to manager mcp surface

---
 hive-ag3nt/src/mcp.rs           | 46 +++++++++++++++++++++++++++++++++
 hive-c0re/src/manager_server.rs | 29 +++++++++++++++++++++
 hive-sh4re/src/lib.rs           | 15 +++++++++++
 3 files changed, 90 insertions(+)

diff --git a/hive-ag3nt/src/mcp.rs b/hive-ag3nt/src/mcp.rs
index e252d10..9fc3ddb 100644
--- a/hive-ag3nt/src/mcp.rs
+++ b/hive-ag3nt/src/mcp.rs
@@ -39,6 +39,7 @@ pub enum SocketReply {
     Status(u64),
     QuestionQueued(i64),
     Recent(Vec<hive_sh4re::InboxRow>),
+    Logs(String),
 }
 
 impl From<hive_sh4re::AgentResponse> for SocketReply {
@@ -65,6 +66,7 @@ impl From<hive_sh4re::ManagerResponse> for SocketReply {
             hive_sh4re::ManagerResponse::Status { unread } => Self::Status(unread),
             hive_sh4re::ManagerResponse::QuestionQueued { id } => Self::QuestionQueued(id),
             hive_sh4re::ManagerResponse::Recent { rows } => Self::Recent(rows),
+            hive_sh4re::ManagerResponse::Logs { content } => Self::Logs(content),
         }
     }
 }
@@ -351,6 +353,15 @@ pub struct RequestApplyCommitArgs {
     pub description: Option<String>,
 }
 
+#[derive(Debug, serde::Deserialize, schemars::JsonSchema)]
+pub struct GetLogsArgs {
+    /// Logical name of the sub-agent container to fetch logs for.
+    pub agent: String,
+    /// How many journal lines to return (default: 50, max: 500).
+    #[serde(default)]
+    pub lines: Option<u32>,
+}
+
 #[derive(Debug, Clone)]
 pub struct ManagerServer {
     socket: PathBuf,
@@ -580,6 +591,40 @@ impl ManagerServer {
         })
         .await
     }
+
+    #[tool(
+        description = "Fetch recent journal log lines for a sub-agent container. Useful \
+        for diagnosing MCP server registration failures, startup crashes, plugin install \
+        errors, or any harness issue you can't see from inside the container. `lines` \
+        defaults to 50 (max capped at 500 on the host side)."
+    )]
+    async fn get_logs(&self, Parameters(args): Parameters<GetLogsArgs>) -> String {
+        let log = format!("{args:?}");
+        let agent = args.agent.clone();
+        run_tool_envelope("get_logs", log, async move {
+            let lines = args.lines.map(|n| n.min(500));
+            let (resp, retries) = self
+                .dispatch(hive_sh4re::ManagerRequest::GetLogs {
+                    agent: agent.clone(),
+                    lines,
+                })
+                .await;
+            let s = match resp {
+                Ok(SocketReply::Logs(content)) => {
+                    if content.is_empty() {
+                        format!("(no journal output for {agent})")
+                    } else {
+                        content
+                    }
+                }
+                Ok(SocketReply::Err(m)) => format!("get_logs failed: {m}"),
+                Ok(other) => format!("get_logs unexpected response: {other:?}"),
+                Err(e) => format!("get_logs transport error: {e:#}"),
+            };
+            annotate_retries(s, retries)
+        })
+        .await
+    }
 }
 
 #[tool_handler(
@@ -635,6 +680,7 @@ pub fn allowed_mcp_tools(flavor: Flavor) -> Vec<String> {
             "update",
             "request_apply_commit",
             "ask_operator",
+            "get_logs",
         ],
     };
     let mut out: Vec<String> = names
diff --git a/hive-c0re/src/manager_server.rs b/hive-c0re/src/manager_server.rs
index 1146b9f..5f90a57 100644
--- a/hive-c0re/src/manager_server.rs
+++ b/hive-c0re/src/manager_server.rs
@@ -273,6 +273,35 @@ async fn dispatch(req: &ManagerRequest, coord: &Arc<Coordinator>) -> ManagerResp
                 },
             }
         }
+        ManagerRequest::GetLogs { agent, lines } => {
+            let n = lines.unwrap_or(50);
+            tracing::info!(%agent, %n, "manager: get_logs");
+            match tokio::process::Command::new("journalctl")
+                .args([
+                    "-M",
+                    agent,
+                    "-n",
+                    &n.to_string(),
+                    "--no-pager",
+                    "--output=short",
+                ])
+                .output()
+                .await
+            {
+                Ok(out) => {
+                    let content = if out.status.success() || !out.stdout.is_empty() {
+                        String::from_utf8_lossy(&out.stdout).into_owned()
+                    } else {
+                        let stderr = String::from_utf8_lossy(&out.stderr);
+                        format!("journalctl exited {}: {stderr}", out.status)
+                    };
+                    ManagerResponse::Logs { content }
+                }
+                Err(e) => ManagerResponse::Err {
+                    message: format!("journalctl spawn failed: {e:#}"),
+                },
+            }
+        }
         ManagerRequest::RequestApplyCommit {
             agent,
             commit_ref,
diff --git a/hive-sh4re/src/lib.rs b/hive-sh4re/src/lib.rs
index 5a6fd0c..314aba6 100644
--- a/hive-sh4re/src/lib.rs
+++ b/hive-sh4re/src/lib.rs
@@ -475,6 +475,17 @@ pub enum ManagerRequest {
         #[serde(default)]
         ttl_seconds: Option<u64>,
     },
+    /// Fetch recent journal lines for a sub-agent container. hive-c0re
+    /// runs `journalctl -M <agent> -n <lines> --no-pager` and returns
+    /// the output as a string. Useful for diagnosing MCP registration
+    /// failures, startup crashes, and harness errors.
+    ///
+    /// `lines` defaults to 50 when omitted.
+    GetLogs {
+        agent: String,
+        #[serde(default)]
+        lines: Option<u32>,
+    },
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -502,4 +513,8 @@ pub enum ManagerResponse {
     Recent {
         rows: Vec<InboxRow>,
     },
+    /// `GetLogs` result: journal lines for the requested container.
+    Logs {
+        content: String,
+    },
 }