Snitch

Latest release	1.6.1
Download	GitHub · Thunderstore
Requires	MelonLoader 0.7.3, S1API Forked 3.1.1, Hotline 1.2.0
API	Reference

A performance profiler for Schedule I - measure what’s actually slow, then make it fast.

🛟 Need help or found a bug? Get support at support.doodesch.de/snitch.

Snitch measures the cost and state of NPCs, trash, quests, and - through a tiny no-op API built on S1API - any other mod’s systems. Its in-game panel lives in the Hotline overlay (each mod gets its own panel), alongside a combined log timeline and a live web dashboard so you can see frame times, section costs, and entity-state distributions in real time.

Features

• Frame time distribution + fps + GC pressure - the load-bearing, build-independent truth.
• Section costs - time named code sections (yours via the API, or vanilla hot paths like NPCMovement.Update).
• State distributions - NPCs by movement/visibility, trash by physics state, quests by state, and your own.
• Per-mod panels - any mod that reports data gets its own panel (counters, state, text, action buttons, toggles) in the Hotline overlay and the web dashboard.
• Log timeline - a combined, chronological view of every mod’s log output, with per-mod filtering.
• Ablation A/B - toggle a subsystem off and measure the real frame-time delta (the causal “total cost”).
• Live web dashboard - opens straight to your local game over WebSocket; your telemetry never leaves your PC.
• Phone remote - scan a QR (in the dashboard or the in-game Snitch panel) to drive the profiler from your phone: live FPS, Start/Stop/Reset, and every mod’s actions and toggles. Works on the same Wi-Fi or across networks, end-to-end encrypted.
• Honest - every number self-certifies; Snitch even reports its own overhead (Snitch.Self).
• Modder API - a zero-overhead no-op when Snitch isn’t installed, so you can ship it with no hard dependency.

Requirements

Requirement	Version / Notes
Schedule I	IL2CPP build
MelonLoader	0.7.x
S1API	ifBars-S1API_Forked
Hotline	The in-game overlay framework Snitch’s panel renders in (auto-installed as a dependency).

Installation

Mod manager (Thunderstore / r2modman): install Snitch; the dependencies (MelonLoader, S1API, Hotline) pull in automatically.

Manual: install MelonLoader 0.7.x, S1API and Hotline, then drop Snitch.dll into the game’s Mods/ folder.

Configuration

Settings live in UserData/MelonPreferences.cfg under Snitch_01_Main (or the in-game Mod Manager UI). The profiler is idle until you run snitch start.

Setting	Default	What it does
Enabled	true	Master switch. OFF = Snitch does nothing.
EnableInMultiplayer	true	Profiling runs locally on every peer; state-mutating levers stay host-only.
AutoStart	false	Begin sampling automatically on world load.
PollHz	4	How often state providers + counters are sampled (frame-time is every frame).
ServerEnabled	true	Run the loopback data server for the web dashboard.
ServerPort	6140	The loopback port (127.0.0.1 only).
ServerToken	(empty)	Optional pairing token for the dashboard.
AllowedOrigins	https://snitch.doodesch.de	Web origins allowed to connect from the browser (localhost is always allowed).

Usage

The in-game overlay is provided by Hotline - press F6 to open it; Snitch’s panel (Start/Stop/Reset plus live stats) is inside, alongside every other mod’s.

Snitch’s own console:

• snitch start / snitch stop - arm / disarm sampling (or the Start/Stop buttons on Snitch’s panel in the Hotline overlay).
• snitch panels - list the per-mod panels (toggle their windows from the Hotline overlay).
• snitch act <id> / snitch toggle <id> / snitch log [<channel>|all] - run a panel action, flip a toggle, or read the logs.
• snitch top / snitch sections / snitch states / snitch counters - log the current numbers.
• snitch vanilla on - attribute CPU cost to vanilla hot paths (e.g. NPCMovement.Update/FixedUpdate).
• snitch ablate <lever> - measure a subsystem’s causal frame cost (built-in npc lever; snitch levers lists them).
• snitch report [md|csv|all] - export to Mods/Snitch/runs/.

Or open the web dashboard at snitch.doodesch.de (or the copy bundled offline at http://localhost:6140/) - it auto-connects and shows frame times, section costs, and state distributions live.

For modders

Your mod’s per-frame methods (OnUpdate etc.) are auto-timed with zero code - it just appears as <YourMod>.OnUpdate once Snitch is sampling. To go further, drop in Snitch.cs (or reference Snitch.Api.dll) - a zero-overhead no-op when Snitch isn’t installed - and either name a class SnitchProbe with a static Register() (auto-discovered, no wiring). There you can build your own panel - counters, state, free text, action buttons, toggles and a log channel, shown in the Hotline overlay and the web dashboard:

using Snitch.Api;   // Profiler, Panel, StateSnapshot
Panel p = Profiler.RegisterPanel("MyMod", "My Mod");
p.Counter("QueueLength", () => _q.Count, "items");                // a numeric gauge
p.State("Jobs", () => new StateSnapshot { Title = "Jobs" }.Add("running", _r)); // a distribution
p.Action("Flush", () => Flush());                                 // a button (replaces a debug hotkey)
p.Toggle("Verbose", () => _v, x => _v = x);                       // an on/off control
p.Log();                                                          // show this panel's log channel
using (Profiler.Sample("MyMod.Pathfinding")) { ... }              // hand-time a sub-section

See the SnitchExample mod for the full surface, and the Modder API wiki page.

How it works

ProfilerRecorder engine counters are inert in Schedule I’s IL2CPP build, so Snitch relies on frame-time + GC as the truth and self-measured section timing (Harmony accumulators) for attribution. The web dashboard (snitch.doodesch.de, source at ScheduleOne-SnitchWeb) is served both from that hosted site and bundled inside the mod for offline use; either way the page connects straight to ws://127.0.0.1:6140 so your data stays on your machine.

Compatibility

Profiling is read-only and safe alongside other mods (it even observes their effects). State-mutating features (the ablation levers) run host-only in multiplayer. The profiler stays idle until you run snitch start.

Credits

Built by DooDesch on S1API by ifBars.

License

MIT - see LICENSE.md.