---
name: break-trace
description: Root-cause a reconciliation break to its source transaction or posting — follow the audit trail from the break row back to the originating entry on each side and state what differs and why. Use after gl-recon has classified a break.
---

# Root-cause a break

Given a single break row (key, GL values, subledger values, bucket, likely cause), trace it to source and produce a root-cause statement.

## Trace path

1. **Pull the GL side** — from the GL system of record, fetch the journal entry or posting that produced this GL line: entry id, posting date, source system, batch id, preparer.
2. **Pull the subledger side** — from the subledger, fetch the matching transaction: trade id, trade/settle dates, counterparty, source feed, FX rate used.

   If no system is connected, ask the user for the GL extract and the subledger extract. Do not invent entry ids or trade ids to fill the gap — an untraceable break is worse than an unstarted trace.
3. **Diff the attributes** — line up posting date, FX rate/date, account mapping, quantity sign, amount sign. The differing attribute is usually the cause.

## Cause → statement

Write the root cause as a single sentence in the form **"⟨side⟩ ⟨did what⟩ because ⟨reason⟩"**, e.g.:

- "GL posted on settle date (T+2) while subledger posted on trade date — timing break, will clear on 2026-05-07."
- "Subledger used WM/R 4pm rate; GL used Bloomberg close — FX break of 12 bps on the base amount."
- "Security ABC123 maps to GL account 11420 in the mapping table but the subledger fed 11410 — mapping break, raise to reference-data."
- "Subledger posted the trade twice (trade ids 88412 and 88419 are duplicates) — duplicate post, suppress 88419."

## Output

For each traced break, return:

```json
{
  "key": "...",
  "root_cause": "one sentence as above",
  "owner": "ops | reference-data | accounting | upstream-system",
  "expected_clear_date": "YYYY-MM-DD or null",
  "action": "monitor | adjust | raise-ticket | suppress"
}
```

Only the resolver writes adjustments — this skill diagnoses, it does not post.