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How to extract entities from an invoice

Run a Nigerian business invoice (PDF) through the v0.2 Pipeline and get back redacted text + a typed list of detections + a signed audit trail. Total time: ~30 seconds end-to-end.

pip install arche-core[doc]   # adds docling for PDF/DOCX/PPTX/XLSX

from collections import Counter
from arche import Pipeline

pipeline = Pipeline(jurisdiction="NG")

result = pipeline.process_file("invoice.pdf")
print(Counter(d.category for d in result.detections))

print(result.redacted_text)   # Safe to share with downstream consumers

The counts depend on your invoice. Running the same two lines on the extracted text of a representative Nigerian invoice line - "Invoice for Fatima Abdullahi, NIN 12345678901, phone 0803 555 7890, phone 0805 111 2222." - gives:

Counter({'PII-1-NAME': 2, 'PII-3-PHONE': 2, 'PII-2-NIN': 1})

Two things the older docs got wrong here: Pipeline takes no audit_log= argument (see the constructor reference), and Result has no summary() method - count over result.detections instead. To persist an audit trail to SQLite, see Persisted audit log.

What gets detected

A standard Nigerian invoice typically surfaces:

Field Pan-African PII Taxonomy category
Sender / recipient name PII-1-NAME
NIN / BVN PII-2-NIN, PII-2-BVN
Email address PII-4-EMAIL
Phone number(s) PII-3-PHONE (libphonenumber-validated)
Bank account / SWIFT BIC PII-7-BANK-ACCOUNT, PII-7-SWIFT
Address PII-1-ADDR
Tax reference (RC number, TIN) PII-2-RC, PII-2-TIN

Each detection carries a confidence (1.0 for structurally validated IDs, lower for shape-only matches) and a statute citation drawn from the auto-loaded NDPA-2023.

Sign the redacted output

When the invoice flows to a downstream processor, sign the redacted text so the recipient can verify provenance offline:

from arche.sign import SignWorkflow, generate_keypair

issuer_key = generate_keypair()   # one-time per issuer
signed = SignWorkflow(jurisdiction="NG").sign(
    result.redacted_text,
    issuer_key,
    purpose="invoice_processing",
)
# `signed` IS the compact JWS string - `SignWorkflow.sign()` returns `str`
# directly. There is no `.serialize()` call. The consumer verifies it with
# arche.sign.VerifyExtractWorkflow - no network call required.
print(signed[:40])
# eyJhbGciOiJFZERTQSIsImtpZCI6ImRpZDprZXk6

See also