AgentTax

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

AI & MLJavaScriptv1.1.1

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.

{
  "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:

  1. In Stripe Dashboard → Developers → Webhooks, add an endpoint:
    https://agenttax.io/api/v1/webhooks/stripe?key=atx_live_YOUR_KEY
    
  2. Select events: payment_intent.succeeded, checkout.session.completed, invoice.paid, charge.succeeded
  3. 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

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:

{
  "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

ToolWhat it doesKey needed
track_paymentLog 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_taxFull sales/use tax calculation with jurisdiction breakdown, audit trail, confidence score and advisoriesDemo works; key for full response
ingest_transactionsBulk-log up to 100 transactions (e.g. x402 purchases), idempotent on external_tx_idYes
list_transactionsYour transaction history with running totalsYes
get_nexus_thresholdsEach state's economic nexus thresholds (revenue / transaction count), notes and DOR sourceNo
get_nexusThe states you have configured nexus inYes
configure_nexusSet the states you have nexus in (merge semantics)Yes
log_tradeLog a buy/sell; sells return realized gain/loss with cost basisYes
list_tradesTrades you have loggedYes
export_1099_daDraft Form 1099-DA payload for realized digital-asset gainsYes (Pro)
get_ratesState sales tax rates and digital-goods taxability, all 51 jurisdictions or oneNo
get_local_rateCombined state + local rate for a zip codeNo
get_capital_gains_ratesState short/long-term capital gains ratesNo
get_pricingMachine-readable pricing contractNo
check_healthAPI health and endpoint listNo

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

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.

Pricing

TierPriceCalls/month
Free$01,500
Starter$25/mo10,000
Growth$99/mo100,000
Pro$199/mo1,000,000
x402$0.005/call in USDC on BasePay per call, no signup

Current machine-readable pricing: get_pricing or GET https://agenttax.io/api/v1/pricing.

Links

License

MIT

Installation

Source-derived launch command. Check the maintainer’s required arguments and credentials before running:

bash
npx -y @agenttax/mcp-server

Set up in your AI client

Merge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.

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

Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.

Claude Desktop setup reference

Package

@agenttax/mcp-servernpm

Compatible MCP Clients

AgentTax works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.

  • Claude Desktop~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.
  • Cursor~/.cursor/mcp.jsonRestart Cursor for changes to take effect.
  • VS Code.vscode/mcp.jsonReload VS Code window for changes to take effect.
  • Windsurf~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect.
  • Claude Code.mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.

Learn More