Snitch

A performance profiler for Schedule I - find out what's actually slow.

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

Snitch measures the cost and state of NPCs, trash, quests, and - through a tiny no-op API - 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, and make your mod (or vanilla gameplay) faster.

Live dashboard · Wiki / docs · Modder example · Support

Features

• Frame time distribution + fps + GC pressure - the load-bearing, build-independent truth.
• Section costs - time named code sections (yours, or vanilla hot paths like NPCMovement.Update).
• State distributions - NPCs by movement/visibility, trash by physics state, quests by state, + your own.
• Per-mod panels - each mod that reports data gets its own toggleable, movable, resizable panel (counters, state, text, buttons, toggles).
• Log timeline - a combined, chronological view of every mod's log output, filterable per mod.
• Ablation A/B - toggle a subsystem off and measure the real frame-time delta (causal "total cost").
• Live web dashboard - opens straight to your local game over WebSocket; telemetry never leaves your PC.
• Honest - every number self-certifies; Snitch even reports its own overhead.
• Modder API - a zero-overhead no-op when Snitch isn't installed; no hard dependency.

Requirements

Use it

Install Hotline (pulled in as a dependency) and press F6 for its overlay; Snitch's panel is inside, with Start/Stop/Reset and live stats. Then snitch start (or the Start button on the panel). Or open the web dashboard at snitch.doodesch.de - it auto-connects and shows everything live. Console verbs: start, stop, status, frame, top, sections, states, counters, panels, act, toggle, log, vanilla on|off, ablate <lever>, levers, report. Reports go to Mods/Snitch/runs/.

For modders

Your mod's OnUpdate etc. are auto-timed with zero code (<YourMod>.OnUpdate). For more, drop in Snitch.cs (or reference Snitch.Api.dll) - a no-op when Snitch isn't installed:

using Snitch.Api;   // Profiler, Panel, StateSnapshot
Panel p = Profiler.RegisterPanel("MyMod", "My Mod");             // your own panel in the overlay + dashboard
p.Counter("Queue", () => _q.Count, "items");                     // a gauge
p.Action("Flush", () => Flush());                                // a button (replaces a debug hotkey)
p.Toggle("Verbose", () => _v, x => _v = x);                      // an on/off control
using (Profiler.Sample("MyMod.Work")) { ... }                    // hand-time a sub-section

Or just name a class SnitchProbe with a static Register() - Snitch discovers and calls it automatically. Full example: ScheduleOne-SnitchExample.

Notes

ProfilerRecorder engine counters are inert in Schedule I's IL2CPP build, so Snitch relies on frame-time + GC and self-measured section timing. Profiling is local and safe in multiplayer; state-mutating features run host-only. Everything is idle until you snitch start.

Credits

Built by DooDesch on S1API.

Changelog

All notable changes to Snitch are documented here. Format based on Keep a Changelog.

[1.3.0] - 2026-06-26

The in-game overlay moves to the new Hotline framework, so every mod shares one overlay and one hotkey. The web dashboard and the profiling itself are unchanged.

Changed

• The in-game overlay is now provided by Hotline (a dependency). Snitch contributes its profiler panel (frame stats, sections, states, Start/Stop/Reset) to the unified Hotline overlay, opened with Hotline's master key (default F6).

Removed

• Snitch's own in-game windowing and its overlay settings (ShowHud, HudFontSize, HudX, HudY, WindowLayouts) and the snitch hud / snitch panel <id> console verbs - the overlay lives in Hotline now.

Note

• Without Hotline, Snitch still profiles and serves the web dashboard, but has no in-game overlay. Hotline is pulled in automatically as a dependency.

[1.2.0] - 2026-06-25

The on-screen overlay becomes a small windowing layer, every mod gets its own panel, and there is a combined log timeline. The modder bridge ABI is unchanged (additive), so existing integrations keep working.

Added

• Multi-window overlay: the profiler HUD is now an "Overview" window alongside per-mod panels and a log "Timeline". Each window is independently shown/hidden, dragged (title bar) and resized (bottom-right grip), with a scrollable body and a layout that persists across restarts.
• Per-mod panels: any mod that reports data gets its own toggleable panel of counters, state distributions, free text, action buttons, toggles and a log channel - in the overlay and the web dashboard. New modder API: the Profiler.RegisterPanel(...) fluent builder (Counter/State/Text/Action/Toggle/Log) and Profiler.Log(...).
• Log timeline: a combined, chronological view of all channels (each mod plus Snitch and the console), with per-mod filtering, both in-game and on the dashboard.
• Arm sampling from the overlay: Start / Stop / Reset buttons in the Overview (no console needed). F6 toggles the overlay and always summons the Overview, so it can't get stuck closed.
• New console commands: snitch panels, snitch panel <id> [on|off|move|size|reset], snitch act <id>, snitch toggle <id>, snitch log [<channel>|all].

Changed

• The on-screen "resize" is now a real window resize (width/height with scrolling); font size is a separate setting. Button labels no longer clip descenders.

[1.1.0] - 2026-06-24

The on-screen HUD is now movable and resizable, and remembers where you put it.

Added

• HUD position and font size are adjustable and persist across restarts: snitch hud move <x> <y>, snitch hud font <n>, and snitch hud reset (back to defaults), plus matching HudX, HudY, and HudFontSize settings (sliders in the Mod Manager UI). The overlay auto-fits, so a bigger font makes a bigger window.
• Drag the HUD with the mouse: grab the body to move it, or its bottom-right corner to change the font size (works while the cursor is free, e.g. with the phone or pause menu open).

Fixed

• The F6 hotkey now actually toggles the HUD (it was documented but never wired up).

[1.0.2] - 2026-06-22

Less code in mods, more profiling for free. No change to the host data/wire protocol or the bridge ABI, so existing integrations keep working.

Added

• Auto-instrumentation: while sampling, every other loaded mod's per-frame methods (OnUpdate, OnFixedUpdate, OnLateUpdate, OnGUI) are timed automatically and shown as <Mod>.OnUpdate - per-mod frame cost with zero code on the mod's side. Toggle with the AutoInstrument preference.
• Zero-wiring registration: a mod's SnitchProbe.Register() is now discovered and called by the host automatically when sampling starts, so a mod no longer wires a registration call into its OnInitializeMelon.

Changed

• Modder API shim class renamed Snitch.Api.Snitch -> Snitch.Api.Profiler (drops the using Prof = ... alias; just using Snitch.Api; then Profiler.Sample(...)). The bridge contract is unchanged, so previously shipped shims still bind and report.
• Cheaper no-op path: the shim's pre-bind host lookup no longer scans every loaded assembly each call.

[1.0.1] - 2026-06-22

Internal cleanup. No functional or behavioural changes.

Changed

• Removed leftover development scaffolding: the dev-only verification probes and all internal "phase"-process references in code comments, console help, and docs.

[1.0.0] - 2026-06-22

Initial release. Feature-complete and verified in-game.

Added

• Frame-time + GC sampler (the load-bearing measurement layer).
• Stopwatch section timer (Snitch.Sample), backing both the modder API and vanilla probes.
• Built-in state providers: NPCs (movement/visibility), trash (physics), quests (state).
• Vanilla CPU cost attribution via Harmony accumulators (snitch vanilla on) - e.g. NPCMovement.Update/FixedUpdate.
• Ablation A/B harness with a stability gate + lever registry (snitch ablate <lever>), built-in npc lever.
• Local HTTP + WebSocket data server (loopback :6140) with CORS/PNA/Origin/token.
• SnitchWeb live dashboard (React + uPlot), bundled offline at http://localhost:6140/.
• Zero-overhead modder API (Snitch.Api) - copy-in source or referenced DLL, no hard dependency.
• In-game HUD, periodic telemetry, and Markdown/CSV report export.