Sales Tax Lookup Skill

Overview

Look up sales tax by ZIP code for a checkout, an invoice or a POS setup screen. The Free plan returns the combined tax rate, so you can try this tax rate API free before you pick a plan. A ZIP code returns the estimated combined rate for that area, and a state code returns the statewide base rate. ZIP+4 codes are accepted. Each response names the city and state. Paid plans break the combined rate into its state, county, city and special district parts, add the tax region name, and say whether the state sources in-state sales at origin or destination, which decides whose local rate a seller charges. To apply the rate to an order, the Sales Tax Calculator API returns the tax amount and total in the same call.

Live Test Sales Tax Lookup Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as SalesTaxLookupSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "SalesTaxLookupSkill",
  "arguments": {
    "zip": "64082"
  }
}

You do not name the tool yourself; the model picks it. Asking about 64082 in the terms this skill covers is enough for it to reach for SalesTaxLookupSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

Argument	Type	Description
`zip`Required	string	The zip code for which you want to get the sales tax rate. ZIP+4 (64082-1234) is accepted and priced at its 5-digit ZIP length 5–10

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "state": "CA",
    "zip": 90210,
    "region": "WEST HOLLYWOOD TOURISM IMPROVEMENT DISTRICT",
    "rate": 0.1025,
    "county": 0.0025,
    "city": 0.0075,
    "special": 0.0325,
    "stateRate": 0.06,
    "cityName": "Beverly Hills",
    "stateName": "California",
    "sourcing": "mixed"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`state`	string	`CA`	Two-letter state code for the tax jurisdiction
`zip`	number	`90210`	ZIP code that was looked up
`region`Premium	string	`WEST HOLLYWOOD TOURISM IMPROVEMENT DISTRICT`	The geographic region or jurisdiction name for the tax rate
`rate`	number	`0.1025`	State sales tax rate
`county`Premium	number	`0.0025`	Estimated county tax rate
`city`Premium	number	`0.0075`	Estimated city tax rate
`special`Premium	number	`0.0325`	Estimated special district tax rate
`stateRate`Premium	number	`0.06`	State-level tax rate included in the combined rate
`cityName`	string	`Beverly Hills`	Primary city name for the ZIP code; null when unknown
`stateName`	string	`California`	Full state name
`sourcing`Premium	string	`mixed`	How the state sources in-state sales: origin (the seller's location rate), destination (the buyer's), mixed (California: state, county and city at origin, district taxes at destination) or none (no state sales tax). Remote sellers use destination rates everywhere

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Online Store Checkout: When a customer enters their shipping ZIP code, e-commerce checkouts apply the matching combined rate to calculate cart totals.
Automated Invoice Generation: B2B billing platforms look up state tax rates to append accurate tax line items to monthly customer invoices.
Point of Sale Calculation: Retail POS systems query store location ZIP codes during setup to store local tax percentages for offline transactions.
Subscription Billing Quotes: SaaS quote generators calculate estimated local taxes before sending multi-state sales proposals to prospective corporate clients.

Other ways to use Sales Tax Lookup Skill

Set up Sales Tax Lookup Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →