STACKGLASS

See what your project is actually doing.

Developer observability and verification for Cursor.

Stackglass is the observability and verification layer for AI-assisted development.

Cursor writes and reasons about code. Stackglass gives that agent evidence about state, tests, failures, history, configuration, contracts, and documentation — so it does not have to guess.

It is not another coding assistant.

What is Stackglass?

A local-first developer platform:

Developer flight recorder
+ Testing laboratory (GlassLab)
+ Change inspector
+ Debugging assistant
+ Project status console
+ MCP server
+ Cursor agent toolkit
+ GlassLens (narrative, session, heat, clusters)

Why Stackglass?

Agents constantly struggle with questions like: what changed, what is broken, why, which tests matter, whether a failure is new, whether coverage regressed, and whether the README still describes reality.

Stackglass connects those events. Example:

token.ts edited → typecheck fails → two auth tests fail → contract drifts → README example goes stale

Ask Cursor what happened? and Stackglass answers with evidence.

glass why turns the same evidence into a narrative. glass session replays the timeline. glass heat shows which files are actually noisy. Failure clusters group related failures so you do not fix them one-by-one.

Features

• GlassCore workspace runtime, config, process execution, permissions, logging
• GlassIndex files, packages, tests, imports, public exports
• GlassTrace development timeline
• GlassWatch classified file events; optional watch.autoRun related tests
• GlassLab discovery, plans, runs, flakes, coverage, mutation, contracts
• GlassLens narrative, session replay, heat, clusters, snapshot compare, suspicious commits
• 22 MCP tools plus resources and prompts (new capability is optional args, never a 23rd tool)
• CLI glass / stackglass
• Cursor plugin rules, skills, agents, commands, hooks
• Local dashboard glass dashboard with live Why / Session / Heat / Clusters views

GlassLab

GlassLab is not npm test with a coat of paint. It discovers frameworks, selects related tests with reasons, parses failures, stores history, and will not invent coverage.

Repeat a run with glass test repeat 5 to probe flakes. A mixed pass/fail across repeats is a candidate flake. A single failure is never labeled a flake.

Dogfood: this repository runs its own tests through the same adapters and CLI.

22 MCP Tools

Project intelligence: project_snapshot, project_activity_timeline, code_context, dependency_trace, change_impact

Version control: git_change_summary, git_history_context

Runtime & debugging: runtime_status, runtime_logs, error_analyze, error_trace

GlassLab: test_discover, test_plan, test_run, test_failure_analyze, coverage_inspect, mutation_test, contract_verify

Integrity: config_audit, env_usage, docs_check, release_readiness

Optional modes (same 22 tools):

Tool	Optional args
project_snapshot	narrative
project_activity_timeline	session
change_impact	heat
git_history_context	rank_suspicious
test_run	files, repeat
test_failure_analyze	cluster

Resources (not tools): stackglass://project, timeline, session, attention, clusters, heat, tests, failures, coverage, runtime, changes, configuration, release.

Full schemas: MCP documentation.

Architecture

See docs/architecture.md. MCP, CLI, dashboard, and plugin share GlassCore.

Installation

Requires Node.js 22.13+. Stackglass is not an npm package. Download stackglass-cli.zip from GitHub Releases or clone and build:

git clone https://github.com/theworker02/stackglass.git
cd stackglass
npm install
npm run build
node cli/dist/bin.js --help

From another project, point at the extracted release or built checkout:

node /path/to/stackglass/cli/dist/bin.js init

Docs: theworker02.github.io/stackglass

Quick Start

cd your-project
glass init
glass status
glass why
glass test related
glass dashboard

Cursor Setup

1. Clone this repository and run npm install then npm run build
2. node /path/to/stackglass/cli/dist/bin.js init in the project
3. Install this repository as a Cursor plugin (layout is at the repo root: .cursor-plugin/plugin.json, mcp.json, rules/, skills/, agents/, commands/, hooks/)
4. Confirm MCP server stackglass is available in Cursor (node runs scripts/stackglass-mcp.mjs from the plugin root; STACKGLASS_ROOT = workspace)

The plugin UI is the local dashboard (glass dashboard) plus MCP resources. Cursor's plugin format does not provide a custom editor sidebar API; Stackglass keeps the capability in CLI/MCP rather than inventing one.

Testing

glass test related
glass test changed
glass test failed
glass test flakes
glass test repeat 5
glass test mutation src/auth/token.ts
glass test coverage
glass test contracts

Failure Investigation

User: Why did the authentication tests suddenly start failing?

Stackglass can provide the agent:

current failures (new / recurring / regression / flake)
failure clusters
timeline + session replay
file heat
recent Git changes
suspicious commits ranked by overlapping files
related source
previous passing run
dependency relationships

The agent forms a grounded diagnosis instead of editing at random. Newest commit is not assumed guilty.

Timeline

14:21:03  file.changed       src/auth/token.ts
14:21:11  typecheck.failed
14:21:31  typecheck.passed
14:21:44  test.failed        token expiration

glass session compresses that into beats. glass heat scores files by events, changes, and failures.

Runtime

runtime_status and runtime_logs cover processes launched or registered through Stackglass only.

Configuration

glass config audits package managers, CI Node versions, ports, and duplicated lockfiles.

Documentation Verification

If README says pnpm dev:web and that script is gone, docs_check reports a documentation mismatch.

Release Verification

glass release / release_readiness never publishes. Publishing requires deliberate user action.

CLI

glass init | status | why | session | heat | clusters | compare | attention
glass doctor | snapshot | timeline | watch
glass test | test related | test changed | test failed | test history
glass test flakes | test repeat | test mutation | test coverage | test contracts
glass error | runtime | changes | config | env | docs | release
glass mcp | adapters | logs | cache | dashboard

If glass is unavailable, use stackglass.

Sample glass status (documentation only)

The following is a documentation sample, not live output from this repository:

STACKGLASS
Branch          feature/auth-refresh
Changes         4 files
Build           not_run
Tests           328 passed / 2 failed
Coverage        84.7%
Runtime         2 processes
Attention       3 item(s)
MCP             local

Your actual glass status prints values from the current workspace. Unavailable fields say no_data / unavailable / not_configured.

Rules

Fifteen Cursor rules ship in rules/, including observe-before-changing, test integrity, no blind snapshot updates, environment safety, and release safety.

Skills

Failure Investigator, Regression Hunter, Test Architect, Flake Hunter, Coverage Analyst, Contract Guardian, Runtime Investigator, Configuration Auditor, Documentation Verifier, Release Inspector.

Adapters

defineTestAdapter in @stackglass/core. Built-in: Vitest, Jest, Node Test Runner, Playwright, Cypress, pytest, unittest, cargo test, go test, .NET test, JUnit.

Privacy

Local-first. No account for core functionality. Source is not uploaded to a Stackglass service. Telemetry is off by default.

Security

See SECURITY.md. Secrets are redacted from MCP, logs, timeline metadata, and doctor bundles.

Development

npm install
npm run typecheck
npm test
npm run build

Roadmap

See ROADMAP.md.

Contributing

See CONTRIBUTING.md and CODE_OF_CONDUCT.md.

License

MIT