diff --git a/crates/trodden/tests/claude_code_plugin.rs b/crates/trodden/tests/claude_code_plugin.rs
new file mode 100644
index 0000000..3deb2f8
--- /dev/null
+++ b/crates/trodden/tests/claude_code_plugin.rs
@@ -0,0 +1,133 @@
+#![cfg(unix)]
+
+use std::{
+    env, fs,
+    os::unix::fs::PermissionsExt,
+    path::{Path, PathBuf},
+    process::{self, Command},
+};
+
+use serde_json::Value;
+
+struct Scratch {
+    dir: PathBuf,
+}
+
+impl Scratch {
+    const HOOKS: &str = concat!(
+        env!("CARGO_MANIFEST_DIR"),
+        "/../../integrations/claude-code/hooks/hooks.json"
+    );
+
+    fn new(name: &str) -> Self {
+        let dir = env::temp_dir().join(format!("trodden-plugin-{name}-{}", process::id()));
+        let _ = fs::remove_dir_all(&dir);
+        fs::create_dir_all(&dir).expect("scratch dir is writable");
+        Self { dir }
+    }
+
+    fn cargo_bin(&self) -> PathBuf {
+        self.dir.join("cargo").join("bin")
+    }
+
+    fn other_bin(&self) -> PathBuf {
+        self.dir.join("other")
+    }
+
+    fn install(&self, dir: &Path, name: &str) {
+        fs::create_dir_all(dir).expect("bin dir is writable");
+        let program = dir.join("trodden");
+        fs::write(&program, format!("#!/bin/sh\necho \"{name} $*\"\n"))
+            .expect("bin dir is writable");
+        fs::set_permissions(&program, fs::Permissions::from_mode(0o755)).expect("program is ours");
+    }
+
+    fn commands() -> Vec<String> {
+        let hooks: Value = serde_json::from_str(
+            &fs::read_to_string(Self::HOOKS).expect("plugin hooks are readable"),
+        )
+        .expect("plugin hooks are JSON");
+        let commands: Vec<String> = hooks["hooks"]
+            .as_object()
+            .expect("hooks map events to groups")
+            .values()
+            .flat_map(|groups| groups.as_array().expect("event lists groups"))
+            .flat_map(|group| group["hooks"].as_array().expect("group lists hooks"))
+            .map(|hook| {
+                hook["command"]
+                    .as_str()
+                    .expect("hook has a command")
+                    .to_owned()
+            })
+            .collect();
+        assert!(!commands.is_empty(), "plugin declares hooks");
+        commands
+    }
+
+    fn run_each(&self, path: &[PathBuf]) -> Vec<String> {
+        let path = env::join_paths(
+            path.iter()
+                .chain(&[PathBuf::from("/usr/bin"), PathBuf::from("/bin")]),
+        )
+        .expect("scratch paths hold no separator");
+        Self::commands()
+            .iter()
+            .map(|command| {
+                let output = Command::new("/bin/sh")
+                    .arg("-c")
+                    .arg(command)
+                    .env_clear()
+                    .env("HOME", &self.dir)
+                    .env("CARGO_HOME", self.dir.join("cargo"))
+                    .env("PATH", &path)
+                    .output()
+                    .expect("sh runs");
+                assert!(output.status.success(), "{command} fails: {output:?}");
+                String::from_utf8(output.stdout).expect("fake trodden prints UTF-8")
+            })
+            .collect()
+    }
+}
+
+impl Drop for Scratch {
+    fn drop(&mut self) {
+        let _ = fs::remove_dir_all(&self.dir);
+    }
+}
+
+#[test]
+fn the_cargo_install_wins_when_the_agent_path_lacks_cargo_bin() {
+    let scratch = Scratch::new("missing-cargo-bin");
+    scratch.install(&scratch.other_bin(), "stale");
+    scratch.install(&scratch.cargo_bin(), "cargo");
+    for printed in scratch.run_each(&[scratch.other_bin()]) {
+        assert_eq!(printed, "cargo hook claude-code\n");
+    }
+}
+
+#[test]
+fn an_agent_path_that_lists_cargo_bin_keeps_its_order() {
+    let scratch = Scratch::new("listed-cargo-bin");
+    scratch.install(&scratch.other_bin(), "preferred");
+    scratch.install(&scratch.cargo_bin(), "cargo");
+    for printed in scratch.run_each(&[scratch.other_bin(), scratch.cargo_bin()]) {
+        assert_eq!(printed, "preferred hook claude-code\n");
+    }
+}
+
+#[test]
+fn a_trodden_found_only_on_path_runs() {
+    let scratch = Scratch::new("path-only");
+    scratch.install(&scratch.other_bin(), "prebuilt");
+    for printed in scratch.run_each(&[scratch.other_bin()]) {
+        assert_eq!(printed, "prebuilt hook claude-code\n");
+    }
+}
+
+#[test]
+fn hooks_stay_quiet_without_trodden() {
+    let scratch = Scratch::new("absent");
+    for printed in scratch.run_each(&[]) {
+        assert_eq!(printed, "");
+    }
+}
diff --git a/integrations/claude-code/hooks/hooks.json b/integrations/claude-code/hooks/hooks.json
index b276739..fc157d4 100644
--- a/integrations/claude-code/hooks/hooks.json
+++ b/integrations/claude-code/hooks/hooks.json
@@ -2,22 +2,22 @@
   "description": "Recall a learned procedure on each prompt and when a command fails with an error a past session fixed; learn from the session when a turn or session ends.",
   "hooks": {
     "UserPromptSubmit": [
-      { "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ],
     "PostToolUseFailure": [
-      { "matcher": "Bash", "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "matcher": "Bash", "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ],
     "SessionStart": [
-      { "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ],
     "Stop": [
-      { "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ],
     "PreCompact": [
-      { "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ],
     "SessionEnd": [
-      { "hooks": [{ "type": "command", "command": "PATH=${PATH:+$PATH:}${CARGO_HOME:-$HOME/.cargo}/bin; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
+      { "hooks": [{ "type": "command", "command": "case :$PATH: in *:\"${CARGO_HOME:-$HOME/.cargo}/bin\":*) ;; *) PATH=${CARGO_HOME:-$HOME/.cargo}/bin${PATH:+:$PATH} ;; esac; command -v trodden >/dev/null 2>&1 || exit 0; exec trodden hook claude-code", "timeout": 5 }] }
     ]
   }
 }