Pipeline Validation (neograph check)

neograph check validates your pipelines without executing them. It discovers every Construct in a Python file (or importable module), runs compile() and lint() on each one, and reports problems.

Basic usage

neograph check my_pipeline.py

Output:

OK    ingestion (pipeline)
FAIL  analysis (analysis_pipeline)
      compile: Node 'score' in construct 'analysis' declares input=RawText but no upstream produces a compatible value.

2 construct(s) checked, 1 passed, 1 failed.

The command accepts a file path or a dotted module name:

neograph check my_pipeline.py
neograph check my_package.pipelines

Providing config for lint

lint() checks that FromInput and FromConfig DI bindings resolve against a config dict. Without a config, only structural checks run. Two flags supply one:

—config (inline JSON)

neograph check my_pipeline.py --config '{"node_id": "test", "project_root": "/tmp"}'

—setup (Python module)

For configs that contain non-serializable objects (rate limiters, database pools), point --setup at a Python file that exports a get_check_config() function:

from my_app.resources import make_limiter

def get_check_config():
    return {
        "node_id": "test",
        "project_root": "/tmp",
        "rate_limiter": make_limiter(),
    }

neograph check my_pipeline.py --setup check_config.py

Exit codes

Code	Meaning
0	All constructs compiled and linted cleanly
1	One or more constructs failed compilation or lint
2	Usage error (file not found, invalid JSON, missing `get_check_config`)

CI integration

Add a check step to your CI pipeline. The non-zero exit code fails the build on any validation error:

name: Pipeline Validation
on: [push, pull_request]

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: astral-sh/setup-uv@v6
      - run: uv sync
      - run: uv run neograph check src/my_pipeline.py --config '{"node_id": "test"}'

What it runs

For each Construct found in the target module:

compile() — builds the LangGraph StateGraph, catching type mismatches, missing upstreams, invalid modifiers, and cycle errors.
lint() — walks every node and checks that DI parameters (FromInput, FromConfig, bundled models) have matching keys in the provided config. See Static Linting for details.

Both checks are assembly-time only — no LLM calls, no side effects.