diff --git a/crates/colibri-daemon/tests/multi_agent_board.rs b/crates/colibri-daemon/tests/multi_agent_board.rs
new file mode 100644
index 0000000..fe0df9d
--- /dev/null
+++ b/crates/colibri-daemon/tests/multi_agent_board.rs
@@ -0,0 +1,159 @@
+use std::path::Path;
+use std::sync::Arc;
+use std::time::Duration;
+
+use colibri_daemon::daemon::DaemonLoopConfig;
+use colibri_daemon::{daemon, socket, DaemonConfig, DaemonState, SharedState};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::net::UnixStream;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn two_agents_claim_distinct_tasks_on_the_board() {
+    let data_dir =
+        std::env::temp_dir().join(format!("colibri-multi-agent-{}", uuid::Uuid::new_v4()));
+    std::fs::create_dir_all(&data_dir).expect("create temp data dir");
+
+    let mut config = DaemonConfig::from_env();
+    config.data_dir = data_dir.clone();
+    config.socket_path = data_dir.join("colibri.sock");
+    config.db_path = data_dir.join("colibri.sqlite");
+    let socket_path = config.socket_path.clone();
+
+    let state: SharedState = Arc::new(DaemonState::new(config));
+
+    let server_state = state.clone();
+    let server_shutdown = state.shutdown_rx.resubscribe();
+    let server = tokio::spawn(async move {
+        let _ = socket::serve(server_state, server_shutdown).await;
+    });
+
+    let loop_state = state.clone();
+    let loop_shutdown = state.shutdown_rx.resubscribe();
+    let loop_config = DaemonLoopConfig {
+        scheduler_interval: Duration::from_millis(50),
+        ..DaemonLoopConfig::default()
+    };
+    let bg_loop = tokio::spawn(async move {
+        daemon::run_loop(loop_state, loop_config, loop_shutdown).await;
+    });
+
+    wait_for_socket(&socket_path).await;
+
+    // Register two agents.
+    let sysadmin = send_command(
+        &socket_path,
+        r#"{"cmd":"register-agent","name":"sysadmin","capabilities":{"freebsd":true}}"#,
+    )
+    .await;
+    assert!(sysadmin["ok"].as_bool().unwrap_or(false));
+    let sa_id = sysadmin["data"]["id"].as_str().unwrap().to_string();
+
+    let dba = send_command(
+        &socket_path,
+        r#"{"cmd":"register-agent","name":"db-admin","capabilities":{"postgres":true}}"#,
+    )
+    .await;
+    assert!(dba["ok"].as_bool().unwrap_or(false));
+    let dba_id = dba["data"]["id"].as_str().unwrap().to_string();
+
+    // Both agents listed.
+    let agents = send_command(&socket_path, r#"{"cmd":"list-agents"}"#).await;
+    assert_eq!(agents["data"].as_array().unwrap().len(), 2);
+
+    // Create two tasks.
+    let zfs = send_command(
+        &socket_path,
+        r#"{"cmd":"create-task","title":"scrub zroot","description":"zpool scrub"}"#,
+    )
+    .await;
+    let zfs_id = zfs["data"]["id"].as_str().unwrap();
+
+    let vacuum = send_command(
+        &socket_path,
+        r#"{"cmd":"create-task","title":"vacuum db","description":"VACUUM ANALYZE"}"#,
+    )
+    .await;
+    let vacuum_id = vacuum["data"]["id"].as_str().unwrap();
+
+    // Both queued.
+    let q = send_command(&socket_path, r#"{"cmd":"list-tasks","status":"queued"}"#).await;
+    assert_eq!(q["data"].as_array().unwrap().len(), 2);
+
+    // Each agent claims one task.
+    let c1 = send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"claim-task","task_id":"{zfs_id}","agent_id":"{sa_id}"}}"#),
+    )
+    .await;
+    assert!(c1["ok"].as_bool().unwrap_or(false), "claim zfs: {c1}");
+
+    let c2 = send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"claim-task","task_id":"{vacuum_id}","agent_id":"{dba_id}"}}"#),
+    )
+    .await;
+    assert!(c2["ok"].as_bool().unwrap_or(false), "claim vacuum: {c2}");
+
+    // Transition both to started, then done.
+    send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"transition-task","task_id":"{zfs_id}","status":"started"}}"#),
+    )
+    .await;
+    send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"transition-task","task_id":"{vacuum_id}","status":"started"}}"#),
+    )
+    .await;
+
+    let active = send_command(&socket_path, r#"{"cmd":"list-tasks","status":"started"}"#).await;
+    assert_eq!(active["data"].as_array().unwrap().len(), 2);
+
+    send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"transition-task","task_id":"{zfs_id}","status":"done"}}"#),
+    )
+    .await;
+    send_command(
+        &socket_path,
+        &format!(r#"{{"cmd":"transition-task","task_id":"{vacuum_id}","status":"done"}}"#),
+    )
+    .await;
+
+    let done = send_command(&socket_path, r#"{"cmd":"list-tasks","status":"done"}"#).await;
+    assert_eq!(done["data"].as_array().unwrap().len(), 2);
+
+    let empty = send_command(&socket_path, r#"{"cmd":"list-tasks","status":"queued"}"#).await;
+    assert!(empty["data"].as_array().unwrap().is_empty());
+
+    state.shutdown_tx.send(()).ok();
+    let _ = tokio::time::timeout(Duration::from_secs(2), server).await;
+    let _ = tokio::time::timeout(Duration::from_secs(2), bg_loop).await;
+    let _ = std::fs::remove_dir_all(&data_dir);
+}
+
+async fn wait_for_socket(socket_path: &Path) {
+    for _ in 0..100 {
+        if socket_path.exists() {
+            return;
+        }
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+    panic!("socket never appeared");
+}
+
+async fn send_command(socket_path: &Path, line: &str) -> serde_json::Value {
+    let stream = UnixStream::connect(socket_path).await.expect("connect");
+    let (reader, mut writer) = stream.into_split();
+    writer
+        .write_all(format!("{line}\n").as_bytes())
+        .await
+        .expect("write");
+    let mut reader = BufReader::new(reader);
+    let mut resp = String::new();
+    tokio::time::timeout(Duration::from_secs(2), reader.read_line(&mut resp))
+        .await
+        .expect("timeout")
+        .expect("read");
+    serde_json::from_str(resp.trim_end()).expect("parse JSON")
+}