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Amazon FBA Fee-Preview Snapshot Drift Monitor

Find silent FBA fee-estimate changes before refreshing margin assumptions.

Amazon FBA US

Included in the $9.00 Shelf Kit

Agent/API — $0.50
Review-first
Every output stays a draft. No credentials
No seller-account login required. Private delivery
Inputs expire after 24 hours. Clear recourse
Digital-service refund policy.

What you receive

  • Earliest-versus-latest price, dimension, weight, and size-band changes
  • Referral, variable-closing, fulfillment, and total fee deltas per unit
  • Price-only, fee-only, measurement/size, mixed, and identifier-only classes
  • Largest supplied per-unit fee increases ranked first against your threshold
  • Added, removed, transient, and recurring snapshot-state context

Who it is for

Amazon FBA sellers, agencies, and finance teams comparing like-for-like seller-supplied Fee Preview exports before updating margin assumptions or reviewing source measurements.

Delivery: usually a structured result, workbook, or ZIP depending on the tool.

How it stays safe

Friday compares only the chronological FBA Fee Preview snapshot rows you supply, matched by SKU and FNSKU. It reads no Amazon account, report, rate card, offer, measurement, or inventory record and verifies no field. A difference is an observed change between supplied estimates—not a finding that a fee is wrong, a prediction of a future charge, or evidence that Amazon remeasured an item. Added or removed rows may reflect report scope. Friday opens no case, files no dispute, changes no offer, price, listing, inventory, or fulfillment setting, does not publish listings, and does not modify a seller account.

Synthetic sample

See the deliverable structure before buying

{
  "changed_listing_count": 5,
  "added_count": 1,
  "removed_count": 1,
  "price_only_change_count": 1,
  "mixed_change_count": 2,
  "fee_increase_count": 2,
  "threshold_exceeded_count": 1,
  "summed_positive_per_unit_fee_increases": 3.25,
  "change_queue_preview": [
    {
      "priority_rank": 1,
      "sku": "NW-DESK-01",
      "fnsku": "X000NWDESK",
      "change_category": "mixed",
      "change_types": [
        "dimensions_changed",
        "weight_changed",
        "size_band_changed",
        "fulfillment_fee_changed",
        "total_fee_changed"
      ],
      "before_size_band": "Large standard-size",
      "after_size_band": "Small oversize",
      "fulfillment_fee_delta": 2.8,
      "total_fee_delta": 2.8,
      "exceeds_fee_increase_threshold": true
    },
    {
      "priority_rank": 2,
      "sku": "NW-BOTTLE-20",
      "fnsku": "X000NWBOTTLE",
      "change_category": "mixed",
      "change_types": [
        "price_changed",
        "referral_fee_changed",
        "total_fee_changed"
      ],
      "price_delta": 3.0,
      "referral_fee_delta": 0.45,
      "total_fee_delta": 0.45,
      "exceeds_fee_increase_threshold": false
    },
    {
      "priority_rank": 5,
      "sku": "NW-MUG-12",
      "fnsku": "X000NWMUG12",
      "change_category": "price_only",
      "change_types": [
        "price_changed"
      ],
      "price_delta": 2.0,
      "total_fee_delta": 0.0
    }
  ],
  "warnings": [
    "All values are seller-supplied snapshot observations and are unverified.",
    "A difference does not mean Amazon's estimate is wrong or establish a future charge."
  ],
  "publish_status": "draft_needs_review"
}

This sample uses synthetic facts. Your output is generated only from the facts you submit.

Agent API and x402 details

POST /v1/amazon/fba/fee-preview-snapshot-drift

Exact x402 price: $0.50. Use the public OpenAPI schema and Base USDC payment flow. The response returns a private job URL and temporary token.

Open the API documentation →

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