# Observed Unit Sales Velocity – Sequential Input-Change Attribution

> Observed Unit Sales Velocity – Sequential Input-Change Attribution is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-16).

Performs waterfall attribution analysis on retail unit sales velocity by comparing before/after sold_units and observed_days inputs to quantify the contribution of each input change.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ar-retail-unit-sales-velocity-waterfall?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/observed-unit-sales-velocity-sequential-input-change-attribution-958eebf8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r_h_jX6PNwLdVS488CBMh

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability observed-unit-sales-velocity-sequential-input-change-attribution-958eebf8 -d '<json body>'
```

Example prompt: I had 84 units sold over 7 days, and now I'm seeing 92.4 units sold over 7.7 days — can you run a sequential waterfall attribution to break down how much each of those input changes contributed to the shift in my unit sales velocity?

## When to prefer this

Choose this endpoint when you need to understand *why* a unit sales velocity metric changed by decomposing the effect of each individual input change (sold units and observation window) sequentially — i.e., a waterfall/attribution breakdown rather than just a before/after delta. It is ideal for retail analysts or agents needing a structured attribution report from simple retail figures without requiring platform access or live data feeds.

## Known failure modes

- observed_days must be greater than 0 (exclusiveMinimum); passing 0 will cause validation failure
- Missing required fields in before or after objects returns an error
- Values exceeding maximum (1e12) may be rejected
- Non-numeric inputs for sold_units or observed_days will fail schema validation
- Payload with extra properties rejected due to additionalProperties: false

## How this service works

Observed unit sales velocity - Sequential input-change attribution: Sequential input-change attribution for Observed unit sales velocity. Supplied retail figures only, up to 200 records. No platform access, live rates or order execution. One of 25 new profiles across 20 shared operations in this industry. 0.01 USDC includes one bounded sequential input-change attribution report.

## Output

A bounded sequential input-change attribution report showing how each individual input change (sold_units and observed_days, applied in sequence) contributed to the overall shift in observed unit sales velocity, based on the supplied before and after retail figures — no live rates or order execution included.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {
   "type": "object",
   "default": {
    "sold_units": 92.4,
    "observed_days": 7.700000000000001
   },
   "required": [
    "sold_units",
    "observed_days"
   ],
   "properties": {
    "sold_units": {
     "type": "number",
     "default": 84,
     "maximum": 1000000000000,
     "minimum": 0
    },
    "observed_days": {
     "type": "number",
     "default": 7,
     "maximum": 1000000000000,
     "minimum": 0,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  },
  "before": {
   "type": "object",
   "default": {
    "sold_units": 84,
    "observed_days": 7
   },
   "required": [
    "sold_units",
    "observed_days"
   ],
   "properties": {
    "sold_units": {
     "type": "number",
     "default": 84,
     "maximum": 1000000000000,
     "minimum": 0
    },
    "observed_days": {
     "type": "number",
     "default": 7,
     "maximum": 1000000000000,
     "minimum": 0,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/observed-unit-sales-velocity-sequential-input-change-attribution-958eebf8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)