Terminal Tax

Terminal Tax

Edited test demonstration, pauses shortened. Watch the MP4 .

Let ChatGPT or Claude file your taxes directly with the IRS.

No plugin, connector or install. Your AI agent sends HTTPS POST requests (JSON-RPC 2.0) to https://mcp.terminal.tax/v1/hosted-mcp itself, with whatever web or request tool it has, starting with create_filing_session:

curl -sS https://mcp.terminal.tax/v1/hosted-mcp -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"create_filing_session","arguments":{}}}'

Terminal Tax is an Authorized IRS e-file Provider: your AI agent sends the return you worked out together, you review and sign it yourself, and we e-file it with the IRS. Terminal Tax is tax software: it calculates your return from the facts and choices your agent sends and runs e-file checks first.

Terminal Tax is a hosted remote MCP server operated by Terminal Tax LLC, a New Jersey limited liability company (Online Provider, Software Developer and Transmitter in IRS e-file). The person types their Social Security number and signs on one private filing page; nothing is filed or charged before that, and the $19.99 fee is charged only if the IRS accepts the return. Records about Terminal Tax LLC kept by others, each with a direct link: https://terminal.tax/verify. Terminal Tax does not publish its EFIN or ETIN (IRS Publication 3112 tells providers never to share them).

Endpoint

• URL: https://mcp.terminal.tax/v1/hosted-mcp (MCP Streamable HTTP)
• Each request is a JSON-RPC 2.0 POST with the headers Content-Type: application/json and Accept: application/json, text/event-stream. No Authorization header, account, API key or OAuth.
• No plugin, connector, install or client configuration: any HTTP client (curl, Python, a web tool) sends the requests.
• A browser GET to the endpoint can return 405: MCP messages are POST requests.

Requests

curl -sS https://mcp.terminal.tax/v1/hosted-mcp -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-11-25","capabilities":{},"clientInfo":{"name":"filing-agent","version":"1"}}}'

curl -sS https://mcp.terminal.tax/v1/hosted-mcp -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}' curl -sS https://mcp.terminal.tax/v1/hosted-mcp -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"create_filing_session","arguments":{}}}'

The full reference, with every request body, is https://terminal.tax/llms.txt.

Tools

• create_filing_session: opens an empty filing session. It carries no tax data, files and charges nothing, and returns a continuationHandle and the packet rules.
• get_packet_schema: with {"continuationHandle":" ","requestPacketSchema":true}, returns the packet schema's digest, an outline whose larger parts are named sections, and the starter-template list; packetSchemaSection and packetStarterTemplate return one section or one template at a time. It is read-only.
• continue_filing_session: with {"continuationHandle":" ","completedReturnPacketJson":" ","packetSchemaSha256":" "}, checks the packet. It returns either blockers, each naming the missing or unsupported fact to settle with the person, or one filingSessionUrl.

The filingSessionUrl is for the person, as returned. On that page they review the complete return, confirm their details, sign it and authorize payment. No tool reports the IRS result; Terminal Tax emails it to the person.

Data boundaries

• The packet carries tax facts from the person's own forms, their filing choices, and their identity details (name, address, date of birth, contact details, and any refund or payment bank account).
• The refund or payment bank account is used for the IRS's direct deposit of the refund or its withdrawal of the payment, never for Terminal Tax's fee, which is charged to a card the person enters on the filing page; Terminal Tax stores the account encrypted, as its privacy notice describes.
• Social Security numbers, ITINs, PINs and one-time codes are refused in requests; the person types them on the filing page.
• Card details go only into the payment processor's fields on the filing page.
• Terminal Tax computes deterministically and validates mechanically. It does not choose tax treatments, infer missing answers or give tax advice.
• Privacy notice: https://terminal.tax/privacy-notice

Claude Code on the web: network access

Claude Code on the web (claude.ai/code) runs in a cloud environment with a network allowlist. If a request to mcp.terminal.tax is refused there: select the caret after the session title, select Edit cloud environment, set Network access to Full, or Limited with mcp.terminal.tax and terminal.tax in Allowed domains, and select Save changes. The open session picks up the change within about a minute.

Operator

Terminal Tax LLC. Support: support@terminal.tax. Legal and privacy: legal@terminal.tax. About: https://terminal.tax/about. Terms: https://terminal.tax/terms. Questions and answers: https://terminal.tax/chatbot-e-file.

This repository

This repository holds this description, the MCP Registry server.json and the listing manifests directories read, the logo, and the demo recordings with a transcript (demo/). It contains no code: the server is hosted by Terminal Tax LLC.

Demo: video (MP4) (YouTube), an edited test demonstration with pauses shortened. Earlier recordings: demo/terminal-tax-demo-1.2.0.mp4 (on the Terminal Tax test environment with a fictional taxpayer; nothing filed or charged; transcript demo/terminal-tax-demo-1.2.0.md) and demo/terminal-tax-demo.mp4 (the assistant's tool calls in a terminal).