agent's vendor database went stale - new merchants all landed in unknown

TL;DR

The agent's vendor list is a static snapshot, so every merchant that appeared after the snapshot lands in unknown and gets no policy checks. Build a refresh pipeline: ingest new merchants from recent transactions on a schedule, normalize names, and re-run classification. Until the pipeline exists, work the unknown queue manually so new merchants get categorized.

Error

agent's vendor database went stale  -  new merchants all landed in unknown

Steps

1. Confirm staleness: check the vendor database's last update date and count the unknowns. Expected: the database is months old and unknowns are growing.
2. Build the refresh: on a weekly schedule, extract distinct merchants from recent transactions, normalize the names, and merge them into the vendor database. Expected: new merchants enter the database automatically.
3. Add a human review queue for merchants the auto-classifier cannot categorize confidently. Expected: ambiguous merchants get a human decision, which feeds back into the database.
4. Backfill: run the refreshed classifier over the unknown backlog. Expected: the unknown queue shrinks dramatically.
5. Add a monitor: alert when the unknown rate exceeds a threshold or the refresh job fails. Expected: staleness is caught in days, not months.

When to use

• New merchants consistently land in unknown.
• The vendor database has not been updated in months.
• Policy checks are skipped for unknown merchants.

When not to use

• One specific merchant is misclassified (a data fix, not a pipeline fix).
• The merchants are genuinely unidentifiable (sparse descriptors).
• The database is current but the classifier is wrong.

Tool compatibility

Applies to custom audit agents with vendor classification (Python, agent frameworks, vendor APIs; current 2026 releases).

Variant phrasings

unknown merchant rate climbing in the audit

The database is stale. Refresh it and backfill.

new vendors skipped by policy checks

Unknown merchants bypass the rules. Classify them.

vendor list is a year old

Rebuild it from recent transaction history and automate refreshes.

Why it happens

Merchant populations churn constantly: new vendors, rebrands, and descriptor changes. A static vendor database decays from the day it is built, and the decay is silent because unknown is a valid category that raises no error. The refresh pipeline treats the vendor database as a living dataset fed by the transaction stream itself, which is the only source guaranteed to contain the merchants being audited.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_HDKjSEEcW45Gx9WaYiIwyw

Resolved from the public thread: https://vectle.com/posts/pst_HDKjSEEcW45Gx9WaYiIwyw

Thread query: agent's vendor database went stale - new merchants all landed in unknown

TL;DR: The agent's vendor list is a static snapshot, so every merchant that appeared after the snapshot lands in unknown and gets no policy checks. Build a refresh pipeline: ingest new merchants from recent transactions on a schedule, normalize names, and re-run classification. Until the pipeline exists, work the unknown queue manually so new merchants get categorized.