# FuelTax IFTA Rates API – Quarter Changes

> FuelTax IFTA Rates API – Quarter Changes is a paid API for AI agents from api.freestylevault.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Returns the changes in IFTA fuel tax rates for a specific quarter compared to the prior period, sourced from the human-reviewed iftach.org quarterly matrix.

## Facts

- Endpoint: GET https://api.freestylevault.com/v1/quarters/%7Bquarter%7D/changes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fueltax-ifta-rates-api-quarter-changes-fae2e194
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gDUGulbv8zsXaVewiNzN_

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 fueltax-ifta-rates-api-quarter-changes-fae2e194
```

Example prompt: What IFTA fuel tax rate changes happened in 2026-Q2? I need to know which jurisdictions updated their rates so I can verify my quarterly filing.

## When to prefer this

Use this endpoint when you specifically need to know what changed between quarters in the IFTA tax rate matrix — ideal for differential updates to tax software, compliance audits, or pre-filing verification workflows. Prefer this over the full committed-rates endpoint when you only need the delta, not the full current matrix.

## Known failure modes

- Invalid or unrecognized quarter format returns an error (e.g. quarter not yet available or malformed like '2026Q2' instead of '2026-Q2')
- Quarter not yet imported/reviewed by human staff returns 404 or empty data
- HTTP 402 PAYMENT-REQUIRED if valid x402 payment signature is not provided
- Rate-limit or authentication errors if signature is malformed or expired
- No changes for a quarter where all jurisdictions held rates flat — data array may be empty

## How this service works

IFTA quarterly tax rate matrix (iftach.org), human-reviewed import each quarter. Reference data. Verify against the official IFTA matrix before filing. Paid endpoints use the x402 payment protocol (base, USDC): expect HTTP 402 with PAYMENT-REQUIRED, retry with PAYMENT-SIGNATURE.

## Output

A JSON object containing a data array of IFTA jurisdiction rate changes for the specified quarter — including jurisdiction codes, fuel types, old and new rates, and effective dates — along with a meta block containing quarter metadata such as source version and review date.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "meta": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fueltax-ifta-rates-api-quarter-changes-fae2e194/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.freestylevault.com](https://www.zero.xyz/host/api.freestylevault.com/llms.txt)