The non_usd rule only checked the Total-block top-level currency, so a
new_po whose line item read 'for 55,206.00 CAD' under a USD Total block
still template-parsed as ok -- a fail-open hole in the fail-closed
gate. Every line item's captured currency and its re-derived body token
must now byte-equal the proven-USD top-level currency; covered by a
line-level CAD adversarial fixture (the existing adv-non-usd only
exercised the Total-block variant) and a candidate-mutation unit test.
Replace the extract_new_po scaffold stub with the full
section-windowed extractor (duplicate-label anchoring, sentinel
ship-to, label-keyed U+2022 bullet split, Decimal money from three
anchored contexts only) and add value-level gate rules V1-V13.
Both new_po_not_implemented scaffold guards are removed; rules 6-8
(unrecognized_status, multiline_unsupported, non_usd) go live.
The gate re-derives every byte proof from the email body so an
extractor bug cannot vouch for itself: amount re-serialization
with a digit/comma border check (the thousands-separator
truncation kill switch), sum(lines)==total against both Total
blocks, anchor/supplier identity proofs, USPS address shape on
the raw pre-enrichment zip, bullet label discipline, and
sentinel/artifact hygiene. Any failure falls closed to the LLM;
a validation failure is never a parsed result.
Refs: #99
Mirror WO PR #99's template-first approach for the Coupa PO processor. Two templates identified from a full 3,448-email triage:
- coupa_new_po (95.5%): scaffolded; fails closed to the LLM until extract_new_po lands.
- coupa_cancellation (2.9%): implemented.
Nested contract with recursive validation, Decimal money, and a fail-closed gate. Derived fields (site_code/trade/fiscal_year) are deferred to a shared post-stage. Comments, revisions, multi-line, and non-USD emails fall back to Bedrock. docs/po-template-parser.md records the investigation, decisions, and remaining work.
Signed-off-by: Adam Moussa <166072409+amoussa1229@users.noreply.github.com>
