The interpreter hook flags dynamic-code-execution sinks: constructs that turn data into running code or hand it to a shell, from eval to native deserialization. It is language-aware, reading each file by its own rules, and it is the deterministic engine behind the interpreter sub-skill, which you can run yourself in scan or check mode.

Run it

Scan the codebase

node ./.lagune/hooks/interpreter.mjs           # scans the whole project
node ./.lagune/hooks/interpreter.mjs -d src    # scans a directory
node ./.lagune/hooks/interpreter.mjs -f app.py # scans a single file

Check a snippet

node ./.lagune/hooks/interpreter.mjs -l javascript -p 'eval(x)'    # => careful
node ./.lagune/hooks/interpreter.mjs -l python -p 'json.loads(x)'  # => safe

These sinks are dual-use: whether attacker-influenced input reaches one is undecidable by a static scan, so every match is a caution to review, never a confirmed finding. The scan prints a single Dynamic-execution sinks to review section, grouped by file. A clean run prints no dynamic-execution sinks found.

Read the flagged code, never run it!

Reason about each sink statically, tracing whether untrusted input reaches it. Never execute or eval the flagged code, nor any remote or runtime-fetched code it pulls in, to "test" what it does.

How to read the verdict

Verdict	Meaning
careful	The snippet contains a dynamic-execution sink for its language. Review it by reading, never by running it.
safe	No dynamic-execution sink was found for the given language.

CLI options

Option	Alias	Value	Description
--pattern	-p	a code snippet	Check one snippet. Repeat to check several, one verdict per line.
--lang	-l	a language	Required with -p: one of javascript, python, php, ruby, java, kotlin, go, rust, c, cpp, csharp.
--dir	-d	a directory	Scope a scan to a directory. Repeats and combines with -f.
--file	-f	a file	Scope a scan to a single file. Repeats and combines with -d.

With no option it scans the whole project. -p needs -l and cannot be combined with -d or -f.

Supported languages

The scan reads these languages, keyed by file extension, each checked against its own set of dynamic-execution sinks.

#	Language	Extensions	Sinks it flags
1	JavaScript / TypeScript	.js, .jsx, .mjs, .cjs, .ts, .tsx, .mts, .cts, .astro, .vue, .svelte, .marko, .riot	eval(), Function constructor, string-body setTimeout/setInterval, vm module, child_process exec, dynamic require(), dynamic import()
2	Python	.py, .pyi	eval/exec, __import__(), os.system/os.popen, subprocess shell=True, pickle.load/loads, yaml.load (unsafe)
3	Ruby	.rb	eval family (instance_eval/class_eval/module_eval/eval), system/exec, backticks or %x, Kernel#open / IO.popen/read/binread / Open3, Process.spawn, Marshal.load
4	Go	.go	exec.Command/exec.CommandContext, plugin.Open
5	PHP	.php	eval(), assert() on string, create_function(), shell exec (system/exec/shell_exec/passthru/popen/proc_open), call_user_func/call_user_func_array, include/require with runtime path
6	Rust	.rs	Command::new, process::Command
7	Java	.java	Runtime.exec, ProcessBuilder, ScriptEngine, ObjectInputStream.readObject
8	Kotlin	.kt, .kts	The JVM sinks: Runtime.exec, ProcessBuilder, ScriptEngine, ObjectInputStream.readObject
9	C#	.cs	Process.Start / new Process, BinaryFormatter, Assembly.Load
10	C	.c, .h	system(), popen(), the exec* family (execl, execve, execvp, …)
11	C++	.cc, .cpp, .cxx, .hpp, .hh, .hxx	system(), popen(), the exec* family (execl, execve, execvp, …)

Best-effort, not exhaustive

It reads source as text, so a sink assembled at runtime, hidden behind an alias, or written in a form it does not recognize can slip past. Treat the table as a strong starting point, not a complete inventory.

tip

The hook guarantees the floor (these sinks exist and where): whether an untrusted value actually reaches one is the judgment the interpreter sub-skill covers.

Frequently Asked Questions

No. It flags dynamic-execution sinks as a caution to review, never a confirmed finding, because whether attacker-influenced input reaches the sink cannot be decided by a static scan.

It reads the languages in the Supported languages table, keyed by file extension, each checked against its own set of sinks. Other languages produce no sinks.