101-03 — Read a contract

What you will build

Mental model linking human contract.md, machine contract.json, and load_contract_spec in Python.

Prerequisites

• 101-02

Files you will touch

Read-only:

• src/forge_lcdl/contracts/pw_chunk_classify/v1/contract.md
• src/forge_lcdl/contracts/pw_chunk_classify/v1/contract.json

Step 1 — Skim Markdown

Open contract.md and note inputs, outputs, examples, failure modes.

Step 2 — Inspect JSON schema keys

Open contract.json and confirm input_schema / output_schema properties align with the Markdown sections.

Step 3 — Load in Python

PYTHONPATH=src python3 - <<'PY'
from forge_lcdl.contracts_api import load_contract_spec

spec = load_contract_spec("pw_chunk_classify", "v1")
print(spec.task_id, spec.version)
print("input keys:", sorted(spec.input_schema.get("properties", {}).keys()))
print("output keys:", sorted(spec.output_schema.get("properties", {}).keys()))
PY

Expected output

Printed pw_chunk_classify / v1 plus non-empty input / output property lists.

Common failures

Verify

Cross-check one required field from JSON against the payload you used in 101-02.

What changed

You can navigate ContractSpec before writing application code.

Next step

101-04 — Debug a failure.