Sverklo

Hallucination-resistant code intelligence for Claude Code, Cursor, Windsurf, and Zed. Semantic search, impact analysis, persistent memory — pick 3. Local, MIT, zero config.

Why

Your AI agent edits UserService.validate(). It doesn't know 47 other functions call it. It hallucinates an import. It forgets the design decision you made yesterday because context was compacted. Tests pass because they mock the dependency. Breaking changes ship.

Sverklo (Russian: сверкло, "drill") gives your agent a structural understanding of your codebase — symbol graph, blast radius, semantic recall, and git-pinned memory — so it stops guessing.

20 MCP tools your agent uses

< 2 s to index a 1,700-file monorepo

0 bytes of your code leave the machine

npm install -g sverklo
cd your-project && sverklo init

That's it. sverklo init auto-detects your installed AI coding agent (Claude Code, Cursor, Windsurf, Zed), writes the right MCP config, appends instructions to your CLAUDE.md, and runs sverklo doctor to verify the setup. No API keys. No cloud. Telemetry off by default.

First-run note. Sverklo's embedding model (all-MiniLM-L6-v2 ONNX, ~86 MB) is downloaded from HuggingFace on first use into ~/.sverklo/models/ and cached forever — every subsequent run is fully offline. Bundling the model into the npm tarball is on the v0.13 roadmap.

Want proof before installing? Browse the /report leaderboard — Sverklo audits of 47 popular OSS repos (express, react-hook-form, vite, lodash, prisma, …) with grade cards for dead code, circular deps, coupling, and security.

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Grep vs Sverklo — the same question, side by side

Every one of these is a query a real engineer asked a real AI assistant last week. Grep gives you lines. Sverklo gives you a ranked answer.

The question	With Grep	With Sverklo
"Where is auth handled in this repo?"	grep -r 'auth' . -- 847 matches across tests, comments, unrelated vars, and one 2021 TODO	sverklo_search "authentication flow" -- top 5 files ranked by PageRank: middleware, JWT verifier, session store, login route, logout route
"Can I safely rename BillingAccount.charge?"	grep '\.charge(' -- 312 matches polluted by recharge, discharge, Battery.charge fixtures	sverklo_impact BillingAccount.charge -- 14 real callers, depth-ranked, with file paths and line numbers
"Is this helper actually used anywhere?"	grep -r 'parseFoo' . -- 4 matches in 3 files. Are any real, or just string mentions? Read each one.	sverklo_refs parseFoo -- 0 real callers. Zero. Walk the symbol graph, not the text. Delete the function.
"What's load-bearing in this codebase?"	find . -name '*.ts' | xargs wc -l | sort -- the biggest files. Not the most important ones.	sverklo_overview -- PageRank over the dep graph. The files the rest of the repo depends on, not the ones someone wrote too much code in.
"Review this 40-file PR — what should I read first?"	Read them in the order git diff printed them	sverklo_review_diff -- risk-scored per file (touched-symbol importance x coverage x churn), prioritized order, flagged production files with no test changes

If the answer to your question is "exact string X exists somewhere," grep wins. Use grep. If the answer is "which 5 files actually matter here, ranked by the graph," you need sverklo.

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Works with every MCP editor

Editor	MCP	Skills	Hooks	Auto-setup
Claude Code	yes	yes	yes	sverklo init
Cursor	yes	—	—	sverklo init
Windsurf	yes	—	—	sverklo init
Zed	yes	—	—	sverklo init
VS Code	yes	—	—	manual
JetBrains	yes	—	—	manual
Antigravity	yes	—	—	sverklo init
Any MCP client	yes	—	—	npx sverklo /path

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Hero tools

Tool	What it does
sverklo_search	Hybrid BM25 + vector + PageRank search. Find code without knowing the literal string.
sverklo_refs	All references to a symbol, with caller context. Proves dead code with certainty.
sverklo_impact	Walk the symbol graph, return ranked transitive callers — the real blast radius.
sverklo_review_diff	Risk-scored review of git diff: touched-symbol importance x coverage x churn.

See all 23 tools below.

Full tool reference

Search — find code without knowing the literal string

Tool	What
sverklo_search	Hybrid BM25 + ONNX vector + PageRank, fused with Reciprocal Rank Fusion
sverklo_overview	Structural codebase map ranked by PageRank importance
sverklo_lookup	Find any function, class, or type by name (typo-tolerant)
sverklo_context	One-call onboarding — combines overview, code, and saved memories
sverklo_ast_grep	Structural pattern matching across the AST, not just text

Impact — refactor without the regression

Tool	What
sverklo_impact	Walk the symbol graph, return ranked transitive callers (the real blast radius)
sverklo_refs	Find all references to a symbol, with caller context
sverklo_deps	File dependency graph — both directions, importers and imports
sverklo_audit	Surface god nodes, hub files, dead code candidates in one call

Review — diff-aware MR review with risk scoring

Tool	What
sverklo_review_diff	Risk-scored review of git diff — touched-symbol importance x coverage x churn
sverklo_test_map	Which tests cover which changed symbols; flag untested production changes
sverklo_diff_search	Semantic search restricted to the changed surface of a diff

Memory — bi-temporal, git-aware, never stale

Tool	What
sverklo_remember	Save decisions, patterns, invariants — pinned to the current git SHA
sverklo_recall	Semantic search over saved memories with staleness detection
sverklo_memories	List all memories with health metrics (still valid / stale / orphaned)
sverklo_forget	Delete a memory
sverklo_promote / sverklo_demote	Move memories between tiers (project / global / archived)

Index health

Tool	What
sverklo_status	Index health check, file counts, last update
sverklo_wakeup	Warm the index after a long pause; incremental refresh

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When to reach for sverklo — and when not to

We're honest about this. Sverklo isn't a magic 5x speedup and it doesn't replace grep. It's a sharper tool for specific jobs.

When sverklo earns its keep:

• You don't know exactly what to search for
• You need to prove dead code (zero references across the whole symbol graph)
• You need the blast radius of a refactor before you start
• You're reviewing a large PR and need to know what to read first

When grep is still the right tool:

• Exact string matching — "does this literal string exist?"
• Small codebases under ~50 source files — just read everything
• Single-file diffs — git diff + Read is hard to beat
• Build and test verification — only Bash runs npm test

If a launch post tells you a tool is great for everything, close the tab.

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How It Works

graph LR
    A[Your Code] --> B[Parse<br/>10 languages]
    B --> C[Embed<br/>ONNX/Ollama]
    B --> D[Build Graph<br/>imports/exports]
    D --> E[PageRank<br/>importance]
    
    F[Agent Query] --> G[BM25]
    F --> H[Vector Search]
    E --> I[PageRank Boost]
    G --> J[RRF Fusion]
    H --> J
    I --> J
    J --> K[Token-Budgeted<br/>Response]

1. Parses your codebase into functions, classes, types (TS, JS, Python, Go, Rust, Java, C, C++, Ruby, PHP)
2. Embeds code using all-MiniLM-L6-v2 ONNX model (384d, fully local) — or any Ollama model via config
3. Builds a dependency graph and computes PageRank (structurally important files rank higher)
4. Searches using hybrid BM25 + vector similarity + PageRank, fused via Reciprocal Rank Fusion
5. Remembers decisions and patterns across sessions, linked to git state
6. Watches for file changes and updates incrementally

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Performance

Real measurements on real codebases. Reproducible via npm run bench (methodology).

Repo	Files	Cold index	Search p95	Impact analysis	DB size
gin-gonic/gin	99	10 s	12 ms	0.75 ms	4 MB
nestjs/nest	1,709	22 s	14 ms	0.88 ms	11 MB
facebook/react	4,368	152 s	26 ms	1.18 ms	67 MB

• Search p95 stays under 26 ms even on a 4k-file monorepo
• Impact analysis is sub-millisecond — indexed SQL join, not a string scan
• 10 languages: TS, JS, Python, Go, Rust, Java, C, C++, Ruby, PHP

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Quick Start

Claude Code

npm install -g sverklo
cd your-project && sverklo init

Creates .mcp.json at your project root and appends sverklo instructions to CLAUDE.md. Safe to re-run. If sverklo doesn't appear in /mcp after restart, run sverklo doctor.

Cursor / Windsurf / VS Code / JetBrains

Use the full binary path (which sverklo) to avoid PATH issues in spawned subprocesses:

{
  "mcpServers": {
    "sverklo": {
      "command": "/full/path/to/sverklo",
      "args": ["."]
    }
  }
}

Config locations: .cursor/mcp.json, ~/.windsurf/mcp.json, .vscode/mcp.json, or JetBrains Settings -> Tools -> MCP Servers.

Antigravity

sverklo init writes the global config at ~/.gemini/antigravity/mcp_config.json. Because Antigravity lacks per-project MCP config, you'll need to re-run sverklo init from each project or use separate keys (sverklo-projA, sverklo-projB).

Any MCP client

npx sverklo /path/to/your/project

First run: The ONNX embedding model (~90 MB) downloads automatically. Takes ~30 seconds on first launch, then instant.

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Why not... (as of 2026-04)

Alternative	Local	OSS	Code search	Symbol graph	Memory	MR review	License	Cost
Sverklo	yes	yes MIT	hybrid + PageRank	yes	git-aware	risk-scored	MIT	$0
Built-in grep / Read	yes	yes	text only	no	no	no	varies	$0
Cursor @codebase	no (cloud)	no	yes	partial	no	no	proprietary	with Cursor sub
Sourcegraph Cody	no (cloud)	no	yes	yes	no	partial	source-available	$9-19/dev/mo
Claude Context (Zilliz)	no (Milvus)	yes	vector only	no	no	no	MIT	$0 + Milvus
Aider repo-map	yes	yes	no	basic	no	no	Apache 2.0	$0
Greptile	no (cloud)	no	yes	yes	no	yes	proprietary	$30/dev/mo

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Audit formats

sverklo audit generates codebase health reports in six formats: markdown, html, json, sarif, csv, and badges. Run sverklo audit --format html --open for a self-contained report with god nodes, hub files, orphan detection, coupling analysis, and language distribution. Use sverklo audit --badge to add an A-F health grade shield to your README.

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CLI tools

Sverklo ships a CLI for CI and local use: sverklo review --ci --fail-on high for risk-scored diff review (auto-detects PR ref in GitHub Actions), sverklo audit for codebase health reports, and a GitHub Action that posts review comments on PRs. Run sverklo audit-prompt or sverklo review-prompt to get battle-tested workflow prompts you can paste into any agent.

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Telemetry

Off by default. Sverklo makes zero network calls unless you explicitly run sverklo telemetry enable. If you opt in, we collect only anonymous usage metrics (no code, no queries, no file paths). Full schema and implementation details in TELEMETRY.md.

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Open Source, Open Core

The full MCP server is free and open source (MIT). All 23 tools, no limits, no telemetry, no "free tier" — that's not where the line is.

Sverklo Pro (later this year) adds smart auto-capture of decisions, cross-project pattern learning, and larger embedding models. Sverklo Team adds shared team memory and on-prem deployment.

The open-core line: Pro adds new things, never gates current things. Anything in the OSS server today stays in the OSS server forever.

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Links

• Website
• npm
• Issues
• First Run Guide
• Benchmarks

License

MIT