CLI

pip install crease puts a crease command on your PATH.

Commands

# Extract to JSON
crease extract incoming.xlsx --template templates/orders.crease.yml > out.json

# Validate only — non-zero exit on errors at or above --fail-on
crease validate incoming.xlsx --template templates/orders.crease.yml \
  --fail-on structural

# Extract + validate together
crease check incoming.xlsx --template templates/orders.crease.yml --compact

# Stream a single entity to JSONL
crease stream incoming.xlsx --template templates/orders.crease.yml --entity order \
  > orders.jsonl

# Batch over a folder — per-file JSON outputs plus an aggregated report
crease batch ./inbox/ --template templates/orders.crease.yml \
  --out ./extracted/ --report ./report.json

Exit codes for crease validate

--fail-on	Exit 0	Exit 1	Exit 2
none (default off)	any verdict	—	—
cell	only when fully valid	cell-level errors only	any structural errors
structural (default)	no structural errors	—	any structural errors

JSON output

crease validate --json and crease check emit a structured report:

{
  "is_valid": false,
  "error_count": 3,
  "errors": [
    {
      "type": "wrong_type",
      "loc": ["order", 47, "quantity"],
      "msg": "Field 'quantity' could not be coerced to integer",
      "input": "twelve",
      "ctx": {"expected": "integer"}
    }
  ]
}

The type field is a stable machine code suitable for downstream routing.