Vyper smart contract compiler internals. Use when working on the Vyper compiler codebase — compilation pipeline, Venom IR, semantic analysis, code generation, testing, or contributing. Triggers on vyper compiler development, Venom passes, AST/semantics changes, codegen work, or test writing.
Pythonic smart contract language targeting the EVM. v0.4.x, Python 3.11+.
uv sync --extra dev # install deps (per-worktree .venv, recommended)
uv run vyper contract.vy # compile a contract
uv run vyper -f ir_runtime contract.vy # inspect Venom IR
uv run vyper -f asm contract.vy # inspect assembly
uv run ./quicktest.sh -m "not fuzzing" # run tests (-nauto by default via setup.cfg)
uv run make lint # enforces code style (same as CI)
Prefix all commands with uv run — it activates the local .venv per invocation, which is necessary in non-interactive shells. Each worktree gets its own .venv, so no cross-contamination.
Alternative: pip install ".[dev]" + PYTHONPATH=. prefix on every command. Never pip install -e . — it creates an egg-link in site-packages that permanently points the venv at one worktree, breaking all others.
Source (.vy)
│
├─ vyper/ast/ → Parse to AST (pre_parser → Python AST → Vyper AST)
├─ vyper/semantics/ → Type check, validate, annotate AST
├─ vyper/codegen/ → AST → s-expr IR (default production pipeline)
├─ vyper/ir/ → s-expr IR → assembly → bytecode
└─ vyper/evm/ → Assembly → bytecode
Experimental Venom path (--experimental-codegen):
├─ vyper/codegen_venom/ → AST → Venom SSA IR
└─ vyper/venom/ → Venom IR optimization passes → assembly
Orchestrated by vyper/compiler/phases.py (CompilerData). Each phase is lazy.
| Directory | Purpose |
|---|---|
vyper/ast/ | Parsing, AST nodes, pre-parser. See AST README |
vyper/semantics/ | Type system, analysis, validation. See Semantics README |
vyper/codegen/ | AST → s-expr IR (default production pipeline) |
vyper/ir/ | s-expr IR → assembly → bytecode. See IR README |
vyper/codegen_venom/ | AST → Venom IR (experimental, --experimental-codegen) |
vyper/venom/ | Venom SSA IR: passes, analysis, assembly emission. See Venom README |
vyper/compiler/ | Pipeline orchestration, settings, output formats. See Compiler README |
vyper/builtins/ | Built-in functions and interfaces |
vyper/evm/ | EVM opcodes, assembler |
vyper/cli/ | CLI entry points (vyper, vyper-ir, venom) |
tests/unit/ | Unit tests (ast, semantics, compiler, venom) |
tests/functional/ | Functional tests (builtins, codegen, grammar, syntax, venom) |
Enforced by make lint (also what CI runs). Includes black, flake8, isort, mypy.
T (e.g. IntegerT, ModuleT)| What | Where |
|---|---|
| Main compile function | vyper.compiler.compile_code() |
| Pipeline phases | vyper.compiler.phases.CompilerData |
| AST parsing | vyper.ast.parse.parse_to_ast() |
| Semantic analysis | vyper.semantics.analyze_module() |
| Legacy codegen | vyper.codegen.module |
| AST → Venom IR | vyper.codegen_venom.module |
| Venom → assembly | vyper.venom.generate_assembly_experimental() |
| CLI entry | vyper.cli.vyper_compile |