| name | neat |
| description | Query a live semantic graph of a running software system — dependencies, runtime traffic, root-cause analysis, blast radius, and incident history. Use this for architecture-level questions before reading source code. |
NEAT skill
NEAT keeps a continuously updated graph of a software system from static analysis + OpenTelemetry. This skill exposes it over sixteen MCP tools: ten read-only graph queries plus six /neat extend tools for instrumentation. The canonical list is MCP_TOOL_NAMES in @neat.is/types.
When to invoke
Reach for these tools when a question would take multiple file reads to answer from source. The graph already has the answer.
| Prompt | Tool |
|---|
| "Is anything weird?" / "find me a bug" | get_divergences |
| "Why is payments-db failing?" | get_root_cause |
| "What breaks if I redeploy service-a?" | get_blast_radius |
| "What does service-a depend on?" | get_dependencies |
| "What does service-b actually call at runtime?" | get_observed_dependencies |
| "Show me recent errors on database:payments-db" | get_incident_history |
| "What changed since the last snapshot?" | get_graph_diff |
| "Which integrations have gone quiet?" | get_recent_stale_edges |
| "Any policy violations right now?" | check_policies |
| "Find nodes matching pg" | semantic_search |
Read tools
get_root_cause
Trace upstream from a failing node to find the actual cause. Walks incoming dependency edges, prefers OBSERVED → INFERRED → EXTRACTED, runs the compatibility matrix at each ServiceNode against the originating DatabaseNode.
Inputs: errorNode (graph node id, e.g. database:payments-db), optional errorId (a specific incident id from get_incident_history).
get_blast_radius
Walk outgoing dependencies from a node and list every downstream component with distance + the provenance of the edge that brought us to it.
Inputs: nodeId, optional depth (default 10, max 20).
get_dependencies
Outgoing dependency tree, deduped to the most trustworthy provenance per (target, edge type) pair. BFS to depth N (default 3, max 10); depth=1 returns direct dependencies only.
Inputs: nodeId, optional depth.
get_observed_dependencies
OBSERVED-only outgoing edges — services and databases the node actually contacted in production. Useful for spotting drift between code and reality.
Inputs: nodeId.
get_incident_history
Recent OTel error events recorded against a node, newest first.
Inputs: nodeId, optional limit (default 20, max 100).
get_divergences
Places where what the code declares (EXTRACTED) doesn't match what production observed (OBSERVED), ranked by confidence × severity. The single most NEAT-shaped query — reach for it on "is anything weird?" or "find me a bug" on an unfamiliar codebase, before get_root_cause when no specific node is failing.
Inputs: all optional — type (one or more of missing-observed, missing-extracted, version-mismatch, host-mismatch, compat-violation), minConfidence (0.0–1.0), node (scope to one node id).
get_graph_diff
Diff a saved graph snapshot against the current live graph — added/removed/changed nodes and edges, with both snapshot timestamps. For change reviews and post-incidents.
Inputs: againstSnapshot (path or http(s) URL of the "before" snapshot).
get_recent_stale_edges
Most recent OBSERVED → STALE edge transitions — integrations that have gone quiet. A CALLS edge that just went stale usually means an upstream stopped calling.
Inputs: optional limit (default 50, max 200), optional edgeType filter (e.g. CALLS).
check_policies
Inspect or dry-run the project's policy.json — architectural assertions in five shapes (structural / compatibility / provenance / ownership / blast-radius). Without hypotheticalAction it returns currently-recorded violations; with one, the violations the action would cause.
Inputs: optional scope, optional hypotheticalAction.
semantic_search
Search nodes by natural-language query. Uses embedding vectors when an embedder is available (Ollama nomic-embed-text → in-process MiniLM → substring fallback) — phrase the query the way you'd describe what you want.
Inputs: query.
Extend tools (/neat extend)
Six surgical tools for filling instrumentation gaps (ADR-081 / ADR-086). Three are read-only diagnostics; three modify instrumentation files, package.json, and the lockfile only. NEAT never calls an LLM — the agent reasons over their output and NEAT never auto-applies.
neat_list_uninstrumented
List first-party, third-party, and gap libraries that need an explicit instrumentation package beyond the auto-instrumentations bundle.
Inputs: none (optional project).
neat_lookup_instrumentation
Look up the registry entry for a library — canonical instrumentation package, version, and registration snippet if one exists.
Inputs: library (npm package name), optional installedVersion.
neat_describe_project_instrumentation
Describe the project's current OTel state: which hook files exist, whether .env.neat is present, which OTel deps are installed.
Inputs: none (optional project).
neat_dry_run_extension
Preview what neat_apply_extension would do — the exact file diff, deps to add, install command — without making any changes.
Inputs: library, instrumentation_package, version, registration_snippet.
neat_apply_extension
Install an instrumentation package and splice its registration into the existing OTel hook file. Idempotent — calling twice with the same args is a no-op.
Inputs: library, instrumentation_package, version, registration_snippet.
neat_rollback_extension
Undo the last neat_apply_extension for a library — removes the dep from package.json and the registration from the hook file. Run the package manager manually afterward to sync the lockfile.
Inputs: library.
Provenance and confidence
Every edge in the graph — and every result that comes out of these tools — carries a provenance: OBSERVED (a live signal — an OTel span or a pull connector's poll of a provider API, confidence 1.0), INFERRED (derived from other edges, confidence 0.6), EXTRACTED (read from source, confidence 0.5), or STALE (was OBSERVED, hasn't been seen recently, confidence 0.3). Tools surface this in their text output so you can weight claims accordingly. See PROVENANCE.md at the repo root for the full model.
Connectors and platform
OBSERVED has two sources: OTel spans the app pushes, and pull connectors that poll a provider's own API and fold the result into the same OBSERVED layer — Supabase, Railway, Cloudflare, Firebase. An integration with no spans can still show OBSERVED edges, incidents, and staleness if a connector covers it, so get_observed_dependencies / get_divergences / get_recent_stale_edges reflect connector-sourced signal too. Connectors are configured outside this skill with neat connector add <provider> / list / remove <id> / test <id> (ADR-130); credentials are env-var references, redacted everywhere — you read the resulting data, never a secret.
A ServiceNode may also carry a platform string — 'cloudflare', 'vercel', 'railway', or 'supabase' — when the extractor recognized the host config (wrangler.toml / vercel.json / railway.toml / supabase/config.toml). A static EXTRACTED signal, shown as the provider badge on the dashboard's service nodes.
Configuration
Set NEAT_CORE_URL if @neat.is/core is not running on http://localhost:8080.
Install
npm install -g @neat.is/mcp
neat install
This registers the server with Claude Code and all sixteen tools become available in any session.
