AgentTax

Name: AgentTax
Author: agenttax

@agenttaxMCP server · External

US sales/use tax, nexus thresholds, capital gains and 1099-DA tools for AI agent transactions.

Taxv1.1.1MITJavaScript

Freeno charge per call

How to install

Runs on your machine from its package; the steps are below.

What it does

Reads
Writes
High impact

At most: creates or changes data: records, files, settings.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally over stdio

This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).

npm@agenttax/mcp-serverv1.1.1

Run

npx -y @agenttax/mcp-server

MCP client config

{
  "mcpServers": {
    "agenttax": {
      "command": "npx",
      "args": [
        "-y",
        "@agenttax/mcp-server"
      ]
    }
  }
}

README4 min readView on GitHub

AgentTax MCP Server

Tax compliance for MCP tool developers and AI agents, powered by AgentTax.

For MCP tool developers

If you build MCP tools that charge for usage, you have sales tax obligations in states where your buyers are located. Most payment processors don't handle this correctly for digital services.

Add AgentTax to your MCP setup and call track_payment after every payment. That's it.

json

{
  "mcpServers": {
    "agenttax": {
      "command": "npx",
      "args": ["@agenttax/mcp-server"],
      "env": {
        "AGENTTAX_API_KEY": "atx_live_your_key"
      }
    }
  }
}

After a payment:

track_payment({
  amount: 49.00,
  buyer_state: "TX",
  buyer_zip: "78701",
  description: "MCP API access — monthly subscription",
  payment_id: "pi_stripe_abc123",
  source: "stripe"
})

Returns your tax liability, compliance status, and logs it to your account. All transactions are viewable in your AgentTax dashboard.

Stripe webhook (fully automated)

For fully automatic tax tracking without calling any tool manually, point your Stripe webhook to AgentTax:

In Stripe Dashboard → Developers → Webhooks, add an endpoint:
```
https://agenttax.io/api/v1/webhooks/stripe?key=atx_live_YOUR_KEY
```
Select events: payment_intent.succeeded, checkout.session.completed, invoice.paid, charge.succeeded
Optional: set metadata.work_type on your Stripe products (compute | research | content | consulting | trading) for precise tax classification

Every payment is automatically classified, taxed, and logged. No code changes required.

Requires a billing address on the Stripe payment. Enable full address collection in your Stripe Checkout settings.

Install

Claude Code

bash

claude mcp add agenttax -- npx @agenttax/mcp-server
export AGENTTAX_API_KEY=atx_live_your_key

Claude Desktop / Cursor / Windsurf

Add to your MCP config file:

json

{
  "mcpServers": {
    "agenttax": {
      "command": "npx",
      "args": ["@agenttax/mcp-server"],
      "env": {
        "AGENTTAX_API_KEY": "atx_live_your_key"
      }
    }
  }
}

Demo mode works without a key (50 calls/day, no account required). Tools marked "Yes" below need AGENTTAX_API_KEY.

Tools

Tool	What it does	Key needed
`track_payment`	Log a payment you received and get your sales tax liability. The main tool for paid MCP servers and APIs.	Demo works; key for history
`calculate_tax`	Full sales/use tax calculation with jurisdiction breakdown, audit trail, confidence score and advisories	Demo works; key for full response
`ingest_transactions`	Bulk-log up to 100 transactions (e.g. x402 purchases), idempotent on `external_tx_id`	Yes
`list_transactions`	Your transaction history with running totals	Yes
`get_nexus_thresholds`	Each state's economic nexus thresholds (revenue / transaction count), notes and DOR source	No
`get_nexus`	The states you have configured nexus in	Yes
`configure_nexus`	Set the states you have nexus in (merge semantics)	Yes
`log_trade`	Log a buy/sell; sells return realized gain/loss with cost basis	Yes
`list_trades`	Trades you have logged	Yes
`export_1099_da`	Draft Form 1099-DA payload for realized digital-asset gains	Yes (Pro)
`get_rates`	State sales tax rates and digital-goods taxability, all 51 jurisdictions or one	No
`get_local_rate`	Combined state + local rate for a zip code	No
`get_capital_gains_rates`	State short/long-term capital gains rates	No
`get_pricing`	Machine-readable pricing contract	No
`check_health`	API health and endpoint list	No

Read-only tools carry the MCP readOnlyHint annotation so clients can auto-approve them.

track_payment

track_payment({
  amount: 49.00,
  buyer_state: "TX",
  buyer_zip: "78701",
  description: "MCP tool subscription",
  payment_id: "pi_stripe_abc123",
  source: "stripe"
})

Returns tax_owed, tax_rate, taxable, transaction_id and a compliance_note. Classification comes from description. Sellers get $0 in states where no nexus is configured; the response says so in nexus_warning.

calculate_tax

calculate_tax({
  role: "buyer",
  amount: 500,
  buyer_state: "TX",
  buyer_zip: "78701",
  transaction_type: "compute",
  work_type: "compute",
  counterparty_id: "seller-agent-123",
  is_b2b: true
})

Optional fields: seller_state / seller_zip (origin-sourced intrastate sales in TX, UT, AZ, TN and some OH sales), use_context (Maryland B2B), digital_content_type (with transaction_type: "digital_good"), seller_remitting.

Nexus

get_nexus_thresholds({ state: "NY" })          // what triggers registration
configure_nexus({ nexus: { TX: { hasNexus: true, reason: "Economic nexus" } } })
get_nexus()                                     // what you have configured

Capital gains and 1099-DA

log_trade({ asset_symbol: "ETH", trade_type: "buy", quantity: 2, price_per_unit: 2500, asset_class: "crypto" })
log_trade({ asset_symbol: "ETH", trade_type: "sell", quantity: 1, price_per_unit: 3100, asset_class: "crypto" })
export_1099_da({ year: 2026 })                  // draft, not a filed return

Get an API Key

bash

curl -X POST https://agenttax.io/api/v1/auth/signup \
  -H "Content-Type: application/json" \
  -d '{"email": "you@example.com", "password": "securepass", "agent_name": "my-mcp-server", "agent_work_type": "compute"}'

All four fields are required; agent_work_type is one of compute, research, information_service, content, consulting, trading. Save the api_key.key from the response — it's only shown once.