# Taxjar — how to use (mcp.ai)

Connect your Taxjar account and use 21 tools for taxes straight from your AI agent. Connect with your own API key. TaxJar provides a comprehensive sales tax API for real-time tax calculations, reporting, and filing.

## Option A — via MCP (recommended)
Remote MCP endpoint (HTTP, streamable): `https://api.mcp.ai/p_taxjar?ms=1787293560000`
Add it as a custom/remote MCP connector in your client (Claude, Cursor, VS Code…), then authenticate when prompted. Once connected, ask the agent to use the server's tools (e.g. `taxjar_calculate_sales_tax_for_an_order`).

## Option B — via direct REST API
Base URL: `https://api.mcp.ai/api/taxjar`
Auth: `Authorization: Bearer sk_live_…` — create a workspace API key at https://mcp.ai/settings/api-keys
Discover endpoints: `GET https://api.mcp.ai/api/taxjar/_endpoints`

### Endpoints
- `POST https://api.mcp.ai/api/taxjar/calculate/sales/tax/for/an/order` — Tool to calculate sales tax for an order. Use when you need an accurate tax calculation including nexus addresses, line items, shipping, and exemptions.
  - body: { amount: number, to_zip: string, to_city?: string, from_zip: string, shipping: number, to_state: string, from_city?: string, to_street?: string, from_state: string, line_items?: object[], to_country: string, customer_id?: string, from_street?: string, from_country: string, exemption_type?: string, nexus_addresses?: object[] }
- `POST https://api.mcp.ai/api/taxjar/create/customer` — Tool to create a new customer with exemption information. Use when you need to add a customer to your TaxJar account for tax exemption management.
  - body: { zip?: string, city?: string, name: string, state?: string, street?: string, country?: string, customer_id: string, exempt_regions?: object[], exemption_type: string }
- `POST https://api.mcp.ai/api/taxjar/create/order/transaction` — Creates a new order transaction in TaxJar for sales tax reporting and compliance. This action records order transactions that will appear in the TaxJar dashboard for tax filing purposes. The transacti
  - body: { amount: number, to_lat?: number, to_lng?: number, to_zip: string, to_city?: string, user_id?: string, shipping: number, to_state: string, sales_tax?: number, to_street?: string, line_items?: object[], to_country: string, exemption_type?: string, transaction_id: string, nexus_addresses?: object[], transaction_date: string }
- `POST https://api.mcp.ai/api/taxjar/create/refund/transaction` — Tool to create a new refund transaction. Use after confirming refund details.
  - body: { amount: number, to_zip: string, to_city?: string, provider?: string, shipping?: number, to_state: string, sales_tax?: number, to_street?: string, line_items?: object[], to_country: string, transaction_id: string, transaction_date: string, transaction_reference_id: string }
- `POST https://api.mcp.ai/api/taxjar/delete/customer` — Tool to delete an existing customer. Use when you need to remove a previously created customer by its ID. Example: "Delete customer cust_12345".
  - body: { customer_id: string }
- `POST https://api.mcp.ai/api/taxjar/delete/order/transaction` — Tool to delete an existing order transaction. Use when you need to remove a previously created order transaction by its ID. Example: "Delete transaction abc123".
  - body: { transaction_id: string }
- `POST https://api.mcp.ai/api/taxjar/delete/refund/transaction` — Tool to delete an existing refund transaction. Use when you need to remove a previously created refund transaction by its ID. Example: "Delete refund 243345".
  - body: { transaction_id: string }
- `POST https://api.mcp.ai/api/taxjar/list/customers` — Lists all customer IDs from your TaxJar account. Returns a paginated list of customer IDs (strings). To get full details for a specific customer (including name, address, exemption type, etc.), use th
  - body: { page?: integer, per_page?: integer }
- `POST https://api.mcp.ai/api/taxjar/list/nexus/regions` — Tool to list existing nexus regions for an account. Use after authenticating your account to discover where you have nexus for sales tax purposes.
- `POST https://api.mcp.ai/api/taxjar/list/order/transactions` — List order transaction IDs within a date range. Returns an array of transaction IDs (strings) for orders created between the specified dates. Use this to discover which orders exist in a date range, t
  - body: { provider?: string, to_transaction_date: string, from_transaction_date: string }
- `POST https://api.mcp.ai/api/taxjar/list/refund/transactions` — Lists refund transaction IDs within a specified date range. Returns an array of transaction IDs only. To get detailed information about a specific refund, use the 'Show refund transaction' action with
  - body: { provider?: string, to_transaction_date: string, from_transaction_date: string }
- `POST https://api.mcp.ai/api/taxjar/list/tax/categories` — Tool to list all product tax categories and their codes. Use when you need to discover available tax categories before assigning them to products.
- `POST https://api.mcp.ai/api/taxjar/show/customer` — Tool to show an existing customer. Use when you need to retrieve details of a specific customer via TaxJar API.
  - body: { customer_id: string }
- `POST https://api.mcp.ai/api/taxjar/show/order/transaction` — Tool to show an existing order transaction by ID. Use when you need to retrieve full details of a specific order transaction after creation or listing.
  - body: { transaction_id: string }
- `POST https://api.mcp.ai/api/taxjar/show/refund/transaction` — Retrieves detailed information about a specific refund transaction from TaxJar. Use this tool when you need to: - View complete details of a refund transaction including amounts, addresses, and line i
  - body: { transaction_id: string }
- `POST https://api.mcp.ai/api/taxjar/show/tax/rates/for/a/location` — Tool to show sales tax rates for a location. Use when you need to retrieve sales tax rates for a specific ZIP code with optional address details (city, state, country, street).
  - body: { zip: string, city?: string, state?: string, street?: string, country?: string }
- `POST https://api.mcp.ai/api/taxjar/summarize/tax/rates/for/all/regions` — Tool to retrieve minimum and average sales tax rates by region. Use when you need a backup of regional tax summary rates.
- `POST https://api.mcp.ai/api/taxjar/update/customer` — Tool to update an existing customer in TaxJar. Use when you need to modify customer details such as exemption type, name, or address information.
  - body: { zip?: string, city?: string, name: string, state?: string, street?: string, country?: string, customer_id: string, exempt_regions?: object[], exemption_type: string }
- `POST https://api.mcp.ai/api/taxjar/update/order/transaction` — Tool to update an existing order transaction. Use when adjusting order details such as amount, shipping, or line items after creation.
  - body: { amount?: number, to_zip?: string, to_city?: string, provider?: string, shipping?: number, to_state?: string, sales_tax?: number, to_street?: string, line_items?: object[], to_country?: string, transaction_id: string, transaction_date?: string }
- `POST https://api.mcp.ai/api/taxjar/update/refund/transaction` — Tool to update an existing refund transaction. Use when adjusting refund details such as amount, shipping, or line items after creation.
  - body: { amount?: number, to_zip?: string, to_city?: string, from_zip?: string, shipping?: number, to_state?: string, from_city?: string, sales_tax?: number, to_street?: string, from_state?: string, line_items?: object[], to_country?: string, customer_id?: string, from_street?: string, from_country?: string, exemption_type?: string, transaction_id: string, transaction_date?: string, transaction_reference_id?: string }
- `POST https://api.mcp.ai/api/taxjar/validate/vat/number` — Validates EU VAT identification numbers against the VIES (VAT Information Exchange System) database. Use this tool to: - Verify VAT number format and validity - Check if a VAT number is registered and
  - body: { vat_number: string }

## Example prompts
- "What can I do in Taxjar?"
- "Show me a summary of my Taxjar account"

## More
- Page: https://mcp.ai/taxjar
- Agent spec (llms.txt): https://mcp.ai/taxjar/llms.txt
- Postman collection: https://mcp.ai/taxjar/postman.json