GenVM Lint

Validate intelligent contracts for safety, correctness, and SDK compliance.

Setup

Requires genvm-linter (included in requirements.txt for boilerplate projects):

pip install genvm-linter

Workflow

Always lint before testing. Run genvm-lint check after writing or modifying a contract. Fix all errors before running tests.

genvm-lint check contracts/my_contract.py

check runs both lint (AST safety) and validate (SDK semantics) in one pass.

Commands

check (recommended)

genvm-lint check contracts/my_contract.py
genvm-lint check contracts/my_contract.py --json  # Machine-readable output

lint (fast AST checks only, ~50ms)

genvm-lint lint contracts/my_contract.py

Catches:

• Forbidden imports (os, sys, subprocess, random, etc.)
• Non-deterministic patterns (bare float usage)
• Contract header structure issues

validate (SDK semantic checks, ~200ms)

genvm-lint validate contracts/my_contract.py

Validates:

• Types exist in SDK (TreeMap, DynArray, Address, etc.)
• Decorators correctly applied (@gl.public.view, @gl.public.write)
• Storage fields have valid types (no dict/list)
• Method signatures correct

schema (extract ABI)

genvm-lint schema contracts/my_contract.py
genvm-lint schema contracts/my_contract.py --json
genvm-lint schema contracts/my_contract.py --output abi.json

typecheck (Pyright/Pylance)

genvm-lint typecheck contracts/my_contract.py
genvm-lint typecheck contracts/my_contract.py --json
genvm-lint typecheck contracts/my_contract.py --strict

Runs Pyright with SDK paths auto-configured. Catches type mismatches, missing attributes, undefined variables.

download (pre-download GenVM artifacts)

genvm-lint download                    # Latest
genvm-lint download --version v0.2.12  # Specific
genvm-lint download --list             # Show cached

Output Formats

Human (default)

✓ Lint passed (3 checks)
✓ Validation passed
  Contract: MyContract
  Methods: 8 (5 view, 3 write)

JSON (--json)

{"ok":true,"lint":{"ok":true,"passed":3},"validate":{"ok":true,"contract":"MyContract","methods":8,"view_methods":5,"write_methods":3,"ctor_params":2}}

Exit Codes

• 0 — All checks passed
• 1 — Lint or validation errors found
• 2 — Contract file not found
• 3 — SDK download failed

Agent Workflow

When fixing lint errors iteratively:

1. Run genvm-lint check contract.py --json
2. Parse JSON for specific errors
3. Fix each error in the contract
4. Re-run check until "ok": true
5. Proceed to tests