# Show HN: Snitch – Deterministic prose claim verifier for coding agents. (OSS)

> Source: <https://github.com/fristovic/snitch>
> Published: 2026-07-10 13:44:08+00:00

**Snitch watches your AI agent so you don't have to.**

[Install](#install) · [Help train Snitch (coming soon)](#help-train-snitch-coming-soon) · [Roadmap](#roadmap)

Snitch is a deterministic prose claim verifier for AI coding agents. It watches transcripts from [Cursor](https://cursor.com), [Claude Code](https://claude.com/claude-code), [Codex](https://github.com/openai/codex), [Pi](https://pi.dev), and [OpenCode](https://opencode.ai), extracts high-confidence claims from assistant text ("all tests pass", "I committed this"), and flags claims contradicted by evidence: tool calls (including subagent merges), tool output, filesystem, git, session lookback (3 prior turns), and same-turn consistency.

```
brew tap fristovic/snitch
brew install snitch
snitch start
```

Snitch Bar opens in the menu bar and starts the claim verifier automatically.

Latest release:

```
curl -fsSL https://raw.githubusercontent.com/fristovic/snitch/main/scripts/install.sh | bash
```

From a cloned repo:

```
./scripts/install.sh
```

After install, open Snitch Bar:

```
snitch start
```

- Downloads or builds
`snitch`

CLI and**Snitch Bar.app**(includes`snitchd`

inside the app) - Installs CLI to
`~/.local/bin`

- Installs
**Snitch Bar.app** to`~/.local/share/snitch/`

- Registers a LaunchAgent to open Snitch Bar at login

Open Snitch Bar once — it lives in the menu bar with no Dock icon:

```
snitch start
```

From the Snitch menu:

| Action | What it does |
|---|---|
Snitching… / Paused / Offline |
Current detection status |
Start Snitching / Stop Snitching |
Turn claim verification on or off |
Latest: … |
Preview of the most recent flagged claim (type + short quote) |
View Details… |
Open Terminal with full details (`snitch log --run <id>` ) |
History ▸ Open Dashboard… |
Open the interactive TUI (`snitch dashboard` ) |
Preferences… |
Open `~/.snitch/config.yaml` |
Quit Snitch Bar |
Stop the daemon and exit |

When a false claim is caught, the menu bar icon alerts and Snitch Bar may show a Notification Center alert (Snitch app icon). Click **View Details…** for the full verification breakdown, or **History ▸ Open Dashboard…** to browse history.

```
snitch status             # is detection running?
snitch dashboard          # browse runs and flagged claims interactively
snitch log --run <id>     # full detail for one agent turn
snitch doctor             # install checklist
```

Snitch stores every agent **turn** as a **run** (with a verdict and claims). A **false claim** is a high-confidence prose claim inside a run that evidence contradicts.

| View | Best for | What you see |
|---|---|---|
`snitch log --run <id>` |
One agent turn | Full breakdown — verdict, prompt, tool calls, every claim with evidence. |
`snitch dashboard` |
Browsing history | Interactive TUI — flip between runs and flagged claims, filter, search, live refresh. |

**Menu bar shortcuts:** **View Details…** runs `snitch log --run <id>`

for the latest flagged claim. **History ▸ Open Dashboard…** runs `snitch dashboard`

.

```
snitch log --run abc12345
snitch dashboard
```

| Item | Description |
|---|---|
Start / Stop Snitching |
Pause or resume claim verification |
| Alert icon | Flashes when a new false claim is caught |
Latest: … |
Disabled preview of the most recent flagged claim |
View Details… |
Open `snitch log --run <id>` for the latest flagged claim |
History ▸ Open Dashboard… |
Open `snitch dashboard` in Terminal |
Preferences… |
Edit `~/.snitch/config.yaml` |
Quit Snitch Bar |
Stop `snitchd` and exit |

| Command | Description |
|---|---|
`snitch start` |
Open Snitch Bar |
`snitch status` |
Detection status (`--detailed` for per-harness stats) |
`snitch log --run <id>` |
Full verification detail for one run (`--trace` , `--json` ) |
`snitch log --harness <name>` |
List recent runs for one agent platform |
`snitch dashboard` |
Interactive TUI for runs and flagged claims (`--harness` filter) |
`snitch replay <path>` |
Run any transcript through the pipeline offline — measure accuracy on your own sessions |
`snitch doctor` |
Debug install checklist (per-harness) |
`snitch uninstall` |
Remove daemon and binaries (`--purge` for data) |
`snitch config` |
View/set configuration |

Snitch runs passively after install — it reads each enabled agent's local transcripts (see [Supported agents](#supported-agents)); Cursor's `~/.cursor/projects`

is watched by default.

When Snitch Bar receives a failed (or optionally warned) run, it posts a macOS Notification Center alert attributed to **Snitch Bar.app** (Snitch head icon). Configure in `~/.snitch/config.yaml`

:

```
notifications:
  enabled: true
  on_warn: false
  rate_limit_s: 5
```

The first notification triggers the macOS permission prompt for Snitch Bar.

| Type | Example prose | Contradiction |
|---|---|---|
`test_pass` |
"all tests pass" | No test run, or test output shows failure |
`command_ran` |
"I ran the command" | No shell tool call in the turn |
`command_succeeded` |
"command ran successfully" | Shell exited with error |
`committed` |
"I committed" | No new commit since turn start |
`pushed` |
"I pushed" | No `git push` shell call |
`file_created` |
"created foo.go" | No matching `Write` + file missing |
`file_modified` |
"updated foo.go" | No matching `Write` /`StrReplace` + file missing |
`file_deleted` |
"deleted foo.go" | No matching `Delete` /`StrReplace` + file still present |
`stub` |
"fully implemented" | Written file is a placeholder (`panic("TODO")` , …) |
`no_action` |
action claims | Zero mutating tool calls in the turn |
`self_contradiction` |
"won't modify X" | Tool call edits X in the same turn |
`count_mismatch` |
"updated all 5 files" | File tool-call count ≠ 5 |
`negation_violation` |
"did not touch tests" | `*_test.*` file edited in the turn |
`tool_write` |
Write tool call | File missing / empty after write |
`tool_str_replace` |
StrReplace tool call | Edit not reflected on disk |
`tool_delete` |
Delete tool call | File still exists |
`tool_shell` |
Shell tool call | Command evidence mismatch |
`tool_read` / `tool_glob` / `tool_task` |
Read / Glob / Task | Tool effect vs disk / subagent evidence |

Snitch persists each turn's full payload (tool calls, git HEAD, file manifest) in SQLite. When verifying recap/summary prose, it can credit evidence from up to **three prior turns** in the same session for:

`committed`

/`pushed`

— git shell or HEAD delta in prior turns`test_pass`

/`command_*`

— shell evidence in prior turns`file_created`

/`file_modified`

/`file_deleted`

— file tools + manifests in prior turns`stub`

— placeholder bodies in files written this turn or prior turns

**Same-turn only:** `no_action`

, `self_contradiction`

, `count_mismatch`

, and `negation_violation`

never use cross-turn lookback.

Recap segments (`### Summary`

, `## Summary`

, horizontal rules) are tagged separately: inaccurate recap claims cap at WARN unless there is zero evidence across the current turn plus lookback.

Snitch watches transcripts from five AI coding agents. Cursor is enabled by default; the others are opt-in.

| Agent | Format | Location | Enable |
|---|---|---|---|
Cursor |
JSONL | `~/.cursor/projects` |
on by default |
Claude Code |
JSONL | `~/.claude/projects` |
`snitch config set platforms.claude.enabled true` |
Codex |
JSONL | `~/.codex/sessions` |
`snitch config set platforms.codex.enabled true` |
Pi |
JSONL | `~/.pi/agent/sessions` |
`snitch config set platforms.pi.enabled true` |
OpenCode |
SQLite | `~/.local/share/opencode/opencode.db` |
`snitch config set platforms.opencode.enabled true` |

After enabling a platform, restart Snitch (`snitch start`

). Each platform's claims, tool calls, and shell output are normalized to a common internal vocabulary, so the verification pipeline works identically across all five.

The dashboard accepts a `--harness`

filter to scope to one agent: `snitch dashboard --harness claude`

.

A community labeling flywheel — mark whether Snitch was right or wrong, report missed claims, and optionally share training examples — is **coming soon**. Labels stay local by default.

When sharing is enabled (dual opt-in: `telemetry.enabled`

+ share flag), a shared example may include:

- the
**claim sentence**(full assistant sentence containing the match) - a
**short surrounding context**(capped ±1–2 sentences) - Snitch’s
**claimed → actual** pair - metadata: claim type, harness, model, verdict, your label, and a hash for dedup

**Never shared:** user prompts, full transcripts, source code, file paths, project paths, or shell dumps.

**0.4.x (this release):** Claim-first UX (flagged sentence → checked),`tool_`

* types,`UNUserNotificationCenter`

alerts.**0.3.x:** Multi-harness ingestion (Cursor + Claude Code + Codex + Pi + OpenCode), session lookback, Snitch Bar notifications with app icon.**Coming soon:** Community labeling and opt-in sync of claim sentences + short context to train a false-positive filter.**Later:** A locally-run false-positive classifier trained on community labels — reduces alert noise by filtering regex hits that aren't genuine claims.**Snitchworks:** A paid team layer — centralized dashboard, policy engine, premium semantic claim extraction.

- Deterministic regex extraction only (no LLM claim parsing) — semantic extraction is a later goal
- Lookback is limited to the current agent session (3 turns), not cross-session history
- Subagent tool calls are merged by
**time window**, not`tool_use_id`

mapping - Consistency checks remain same-turn only
- File manifests hash paths touched by tool calls at turn end; out-of-band disk changes may be missed

By participating, you agree to follow the [Code of Conduct](/fristovic/snitch/blob/main/CODE_OF_CONDUCT.md).