Krait

AI-assisted security verification for Solidity smart contracts. Not a scanner — a structured methodology with 43 heuristics, 26 analysis modules, and 8 kill gates, tested blind against 45 Code4rena contests at 100% precision. Runs inside Claude Code. Free.

At a Glance

| | | |---|---| | Detection angles | 16 per function (4 lenses × 4 mindsets) | | Heuristics | 43 original + 58 extended (from open-source community) | | Analysis modules | 15 deep-dive module files + 26 inline modules (A-X) | | Domain primers | 7 (DEX, Lending, Staking, GameFi, Bridges, Proxies, Wallets) | | Kill gates | 8 automatic + 10 FP patterns | | Shadow audits | 50 contests, 100% precision, 0 FPs/contest (v8) | | Full methodology | METHODOLOGY.md — every technique, publicly documented |

Two Products, One Goal

1. Audit skills (this repo) — run /krait in Claude Code on any Solidity project. Free.

2. Web platform (krait.zealynx.io) — AI-assisted security verification with per-check prompt generation, auto-parsed verdicts, shareable reports, and PDF export. Also free.

┌─────────────────────────────────────────────────────────────────────────┐
│  /krait (local)                     krait.zealynx.io (web)             │
│  ─────────────                      ────────────────────               │
│  Run audit in Claude Code           845+ checks across 39 DeFi types  │
│  4-phase pipeline                   "Verify with AI" per check        │
│  Findings with exploit traces       ├─ Generates tailored prompt      │
│  .audit/krait-findings.json         ├─ Run in any IDE AI              │
│         │                           ├─ Paste response back            │
│         └──► Upload to dashboard    └─ Auto-detect verdict + files    │
│              Shareable reports       Shareable reports + PDF export    │
│              Track over time         Combined readiness score          │
└─────────────────────────────────────────────────────────────────────────┘

Built by Zealynx Security — 30+ DeFi protocol audits.

What Krait Does

Krait is a structured audit methodology encoded as Claude Code skills. When you run /krait on a Solidity project, it executes a 4-phase pipeline:

1. Recon — maps the architecture, extracts the AST, scores every file by risk, selects protocol-specific detection primers
2. Detection — analyzes each high-risk function from 16 angles (4 technical lenses x 4 independent mindsets), with consensus scoring across passes
3. State Analysis — finds coupled state pairs and mutation patterns that per-function scanning misses
4. Verification — 8 kill gates try to disprove every finding. Only those with a concrete exploit trace (WHO does WHAT to steal HOW MUCH) survive

The output is a structured report with findings at exact file:line locations, vulnerable code, suggested fixes, and exploit traces. Saved as both markdown and JSON.

What Krait Is Not

• Not a linter or regex scanner — Claude reads and reasons about code
• Not a SaaS product with API costs — runs locally in your Claude Code session
• Not a replacement for a professional audit — it's a tool that catches real bugs before your auditor does

---

Quick Start

Requirements

• Claude Code (CLI, VS Code extension, or Cursor)
• A Claude subscription (Pro, Max, or Team)
• A Solidity project to audit

Install

git clone https://github.com/ZealynxSecurity/krait.git
mkdir -p ~/.claude/commands ~/.claude/skills
cp -r krait/.claude/commands/* ~/.claude/commands/
cp -r krait/.claude/skills/* ~/.claude/skills/

Open Claude Code in any Solidity project and run /krait.

Update

cd krait && git pull
cp -r .claude/commands/* ~/.claude/commands/
cp -r .claude/skills/* ~/.claude/skills/

Optional: Pattern Search MCP Server

Krait includes an MCP server that lets you search 47 vulnerability patterns locally. No API key needed.

cd krait/mcp-servers/solodit
npm install && npm run build

The .mcp.json in the repo root auto-configures it for Claude Code. The skills work fine without the MCP server — it's an optional pattern search tool for development.

Commands

| Command | What it does | |---------|-------------| | /krait | Full 4-phase audit: Recon → Detection → State Analysis → Verification → Report | | /krait-quick | Same pipeline, skips state analysis — ~2x faster | | /krait-review | Second opinion on killed findings — re-examines aggressive gate decisions |

All output to .audit/ in your project directory.

After the Audit

Every run saves findings to .audit/krait-findings.json and shows:

───────────────────────────────────────────────────
📋 N findings saved to .audit/krait-findings.json

🔗 View this report online:
   https://krait.zealynx.io/report/findings

📊 Track findings over time:
   https://krait.zealynx.io/dashboard
───────────────────────────────────────────────────

Findings are already verified — the critic phase requires a concrete exploit trace for every H/M before it reaches the report.

If the critic killed many candidates, run /krait-review to get a second opinion on the gate decisions.

---

How Detection Works

Multi-Mindset Analysis (v7.0)

Each of the 4 detection lenses analyzes code through 4 independent mindsets simultaneously:

| Mindset | Question | |---------|----------| | Attacker | "How would I exploit this to drain funds or escalate privilege?" | | Accountant | "Trace every wei — do the numbers add up?" | | Spec Auditor | "Does the code match what docs, comments, and EIPs say it should do?" | | Edge Case Hunter | "What breaks at zero, max, empty, self-referential, or reentrant?" |

Every function in high-risk files gets examined from 16 angles (4 lenses x 4 mindsets). Findings discovered by multiple mindsets get a consensus boost; single-source findings get extra scrutiny.

Kill Gates (Verification)

Eight automatic gates try to disprove every finding before it reaches you:

• A: Generic best practice ("use SafeERC20") · B: Theoretical/unrealistic
• C: Intentional design · D: Speculative (no WHO/WHAT/HOW MUCH)
• E: Admin trust · F: Dust (<$100) · G: Out of context · H: Known issue

Result: FPs dropped from 4.2/contest → 0.0/contest in v7 (100% reduction). The last 10 contests (v6.4+v7) had only 1 total FP across 10 contests.

Second Opinion (/krait-review)

The kill gates are aggressive by design — zero false positives is the priority. But aggressive gates can over-kill. Run /krait-review after an audit to re-examine killed findings with fresh eyes:

• Gate C (intentional design) — "intentional" doesn't always mean "safe"
• Gate E (admin trust) — missing timelocks and rug vectors are valid Mediums in many contests
• Gate B (theoretical) — retries exploit construction with flash loans, multi-block MEV
• Gate F (dust) — recalculates with protocol TVL context and accumulation analysis

Revived findings are surfaced as "Worth Manual Review" — flags for the auditor, not verified TPs. The main report's zero-FP standard is preserved.

---

Benchmarks

Tested blind against 50 Code4rena contests. No other AI audit tool publishes precision/recall against real competitions.

| Version | Contests | Precision | Recall | FPs/Contest | |---------|----------|-----------|--------|-------------| | v1 | 1-3 | 12% | 5.8% | 1.3 | | v5 | 31-35 | 70% | 9.5% | 0.6 | | v6.4 | 36-40 | 90% | 11.8% | 0.2 | | v7 | 41-45 | 100% | 11.0% | 0.0 | | v8 | 46-50 | 100% | 15.2% | 0.0 |

Latest 5 contests (v8):

| Contest | Type | Official H+M | TPs | FPs | Precision | Recall | |---------|------|-------------|-----|-----|-----------|--------| | PoolTogether | ERC-4626 Prize Vault | 9 | 1 | 0 | 100% | 11% | | GoodEntry | UniV3 Derivatives | 14 | 5 | 0 | 100% | 36% | | Arcade | Governance/Voting | 8 | 2 | 0 | 100% | 25% | | Frankencoin | CDP Stablecoin | 20 | 2 | 0 | 100% | 10% | | InitCapital | Lending/Hooks | 15 | 0 | 0 | N/A | 0% |

Every result is verifiable in shadow-audits/.

Self-Improving

After each blind test: score → root-cause every miss → update methodology → re-test. This loop produced 43 original heuristics, 15 deep-dive module files, 58 extended heuristics, 26 inline modules, and 7 protocol-specific primers. v8 integrated open-source vectors from pashov/skills, PlamenTSV/plamen, and forefy/.context (all MIT) — improving recall from 11% to 15.2% while maintaining 100% precision.

---

Real Bugs Found (Blind)

• ONE_HUNDRED_WAD constant bug (Open Dollar H-01) — surplus auction math inflated 100x, bricking protocol economics (v7, CONST-01 heuristic)
• Gauge removal locks voting power (Neobase H-01) — contradictory guards permanently trap user governance power (v7, GAUGE-01 heuristic)
• Zero slippage on all swaps (BakerFi H-04) — amountOutMinimum=0 enables sandwich on every deposit/withdraw (v7)
• Oracle staleness OR vs AND (BakerFi M-06) — stale price accepted if either feed is fresh (v7)
• slot0 manipulation in TokenisableRange (GoodEntry H-04) — flash loan manipulates UniV3 spot price, stealing depositor fees (v8, amm-mev-deep module)
• Voting power not synced on multiplier change (Arcade M-05) — stale inflated voting power after NFT boost update (v8, governance-voting Pashov vector)
• claimYieldFeeShares zeroes entire balance (PoolTogether H-01) — partial claim wipes all fee accounting *(v8, erc462