Wedge for your dev team

Stop your AI agent from guessing about your code.

Faultlines ships an MCP server that Cursor, Claude Code, Cline, and Aider call to get precise codebase context — features, owners, hotspots, live errors from Sentry, and the right symbols. Same data your engineering leaders see — never your raw source code.

Guesswork removed, not just tokens

Your agent stops reading the wrong files and asking you what owns what. It pulls the feature map, finds the relevant symbols, and answers with the same context you’d hand a senior engineer on day one.

Right-file accuracyfunction-level, not folder-level
Owner & hotspot lookupone tool call, not a Slack thread
Change-impact & regression risksurfaced before the PR
Live errors per featureSentry + PostHog joined automatically

Side benefit: 60–80% fewer tokens per query vs a naive grep-and-read workflow (~15k → ~3k with--symbols).

13 tools your agent can call
list_featuresfind_featureget_hotspotsget_feature_ownersget_feature_filesget_flow_filesget_repo_summaryanalyze_change_impactget_regression_riskfind_symbols_in_flowfind_symbols_for_featureget_feature_errorsget_feature_pageviews

Your AI agent gets the feature map, bug hotspots, owners, coverage — plusimpact analysis (which features break, missing co-changes, regression risk),symbol-level precision (read only the functions that matter, not whole files), andlive runtime signal from your Sentry and PostHog accounts.

# Install
pip install 'faultlines[mcp]'
# ~/.cursor/mcp.json
{
  "mcpServers": {
    "faultlines": {
      "command": "faultlines-mcp"
    }
  }
}

Three deployment modes. Same agent toolkit.

Your MCP server runs where your privacy posture demands. The tool API stays identical — only the data path changes. Pick once at the org level; switch any time as your compliance bar shifts.

Hosted MCP

All tiers · default

The MCP server runs in our cloud. Your agent calls it over HTTPS with an org-scoped token. Lowest setup friction — works with hosted agents like Claude.ai web in addition to local ones.

  • Standard privacy mode
  • Cursor · Claude Code · Cline · Aider · Claude.ai web
  • Sentry + PostHog joined server-side

Local MCP

Business and above

The MCP server runs as a local process on your dev’s machine. It pulls encrypted scans from us, decrypts with your org key in memory, and serves the agent with rich data we never see in plaintext.

  • Private mode (encrypted names + paths)
  • Cursor · Claude Code · Cline · Aider · all local agents
  • Org key never leaves your machine

MCP in your VPC

Enterprise · self-hosted

The entire Faultlines stack — engine, dashboard, MCP — deploys as a Docker image inside your infrastructure. Agents call your internal endpoint. Faultlines.com only sees a license-check ping.

  • Sovereign mode
  • Air-gapped deployment supported
  • BYO LLM key — every byte stays on your side

Live runtime signal in every agent prompt

Your agent doesn’t just see static feature shapes. It sees which features are failing in production, which are hot in the dashboard, and which had a coverage drop in the last PR — pulled live from your Sentry and PostHog accounts.

Sentry → feature

Each Sentry stack trace is matched against the scan from the same commit. The agent calls  get_feature_errors   and gets “Billing → 47 errors last week, top: TypeError in handleCheckout” — not a generic error feed.

Zero SDK changes. We read stack-frame filenames + release commit SHA and join through your scan’s path index.
PostHog → feature

Page views and custom events tagged by URL get mapped to features via the scan’s route index. The agent can answer “which feature has the highest bounce” or “is anyone using the new Settings page” without any code instrumentation.

One env var enables it:  NEXT_PUBLIC_POSTHOG_APP_VERSION=$VERCEL_GIT_COMMIT_SHA.

Always fresh. Never stale.

After every push, a Faultlines incremental scan runs (~5 seconds, cents in LLM cost). Your branch’s scan updates, your agent’s context updates. Same applies to PR branches — feature/auth-v2 has its own current scan, separate from main.

~5s
incremental scan after push
< $0.01
per scan in LLM cost
stable
feature IDs across rename / split / merge
per-branch
your agent sees the same code as your IDE

Works with the agents your team already uses

Any MCP-compatible client. Drop the server into the config, restart the agent, and start asking questions about your codebase that previously required a senior engineer.

Cursor Claude Code Cline Aider Continue Any MCP client

The same map your engineering leaders use to plan

The feature map and ownership graph that powers these tools is the same artifact your EM/CTO uses to decide what to refactor next quarter — and it’s the same data the PR comment posts on every pull request.