Monitor Amazon Flat File Uploads and Fix Errors Faster

Parsing Amazon's processing summary by hand is tedious. You download it, open it in a spreadsheet, and scroll through tab-separated columns hunting for error codes. Error codes are cryptic. Column layouts shift between templates. Finding which SKUs failed, and why, means working through the report row by row.

Rufusly's flat file monitor automates the parsing. It captures the processing summary from Amazon, matches errors by column name (not position, so it works across marketplace templates), and shows you a clear breakdown of what succeeded, what failed, and what each error code means. If you have already read our guide to fixing flat file errors like 12998 and 90057, this is the tool that catches those errors automatically.

Two ways flat files reach Amazon

Rufusly handles flat file monitoring for both paths sellers use to update listings in bulk.

Manual upload on Seller Central: you upload a flat file through Amazon's item manager as normal. The Rufusly browser extension detects the completed upload, reads the processing summary directly from the page, and sends it to your account for parsing. You do not need to download the report yourself. For setup details, see the Flat File Tools documentation.

API submission through Rufusly: when you publish listing changes from the product editor, Rufusly submits them to Amazon via the Feeds API using the JSON_LISTINGS_FEED format. It builds the feed document, uploads it, submits the feed, and polls Amazon for the result. The processing summary is captured and parsed the same way as a manual upload.

How the processing summary parser works

Amazon's processing summaries are tab-separated text files. The column names vary between marketplaces and templates: a UK template might say "Error Message (English)" where a US template says "Error Message". Older templates use different column orders entirely.

The parser handles this by matching columns by name, not by position. It normalises each header, then searches for known aliases across marketplaces. If the exact name is not found, it falls back to a substring match. This means the parser works with UK, EU, US, and older template formats without needing a per-template configuration.

For each row in the summary, the parser extracts the SKU, error code, severity (error or warning), and message. It also reads the aggregate counts from the header block: total records processed, records successful, errors, and warnings. If the header block is missing (some older reports omit it), the parser derives the counts from the individual rows.

What the monitor shows you

The monitor groups results into three views:

• Aggregate counts: how many SKUs were processed, how many succeeded, and how many returned errors or warnings.
• Per-issue detail: each error or warning listed with its severity badge, error code, the affected SKU, the error message, and which attribute caused the problem.
• Errors separated from warnings: Amazon labels some issues as warnings (like error 12998 for fulfilment channel codes) that do not technically reject the row but can still cause real problems like FBA listings silently switching to FBM.

How the extension captures reports from Seller Central

When you navigate to Amazon's item manager page to upload a flat file, the Rufusly browser extension activates. It watches for completed uploads by looking for rows marked "Done" or "Completed" in the upload table.

When the extension finds a completed upload, it locates the report link, extracts the batch ID to avoid processing the same report twice, fetches the report text, and sends it to the Rufusly backend. The backend parses the report and stores the results against your account.

Report capture is deduplicated per browser session. If you refresh the page, the extension will not re-process reports it already captured during that browser session. This prevents duplicate entries when you check back on the item manager page repeatedly.

How API submission works

When you publish through Rufusly directly, the system follows Amazon's Feeds API pipeline:

1. Rufusly builds a JSON_LISTINGS_FEED document with the correct language tags for your marketplace.
2. It creates a feed document on Amazon and receives a pre-signed upload URL.
3. The listing data is uploaded to that URL.
4. The feed is submitted to Amazon for processing.
5. Rufusly polls Amazon at regular intervals until the feed status changes to done or fails.

The result, including any errors or warnings, is stored in your account and shown in the product editor. Feeds that have not completed after 48 hours are marked as abandoned. A background job handles the polling so you do not need to keep the page open.

Pre-upload checks

Before you upload a flat file, Rufusly can run deterministic checks on the data to catch common problems before Amazon sees them. These are not AI-based guesses. They are exact-match validations against known error triggers: incorrect fulfilment channel codes, shorthand listing action values, missing required fields, and quantity values on FBA rows.

Catching these before upload saves a round trip to Amazon. A flat file with 68 SKUs takes several minutes to process on Amazon's side. If 60 of those rows have the same fulfilment channel code error, that is time wasted on a problem that could have been flagged in seconds.

What the monitor does not do

The monitor does not automatically fix errors or resubmit corrected files. It parses and displays what Amazon reports. The reason is straightforward: some errors require a judgement call. A brand name mismatch (error 8541) could mean your file is wrong, or it could mean Amazon's catalogue data is out of date and needs a case opened to correct it. Automatically resubmitting would just produce the same error.

The monitor also captures up to 2,000 issues per processing summary. Uploads with more than 2,000 individual errors will have the first 2,000 stored in detail with the remainder reflected only in the aggregate counts.