irs-taxpayer — Claude Code MCP server: what it does, how to install
Local US tax estimation tools for TY2024 through TY2026. Computes federal liabilities, standard deductions, and supported state taxes inside your coding agent.
claude mcp add irs-taxpayer -- npx -y irs-taxpayer-mcpWhat irs-taxpayer does
This MCP server brings 44 local tools for individual US tax estimations across the 2024 through 2026 tax years. Its deterministic calculation engine evaluates federal income brackets, selected tax credits, and deduction methods. State tax computations are handled explicitly. Instead of applying a rough top-bracket guess, the engine halts when a state is not supported.
The package operates as a standalone CLI questionnaire or as an MCP server for AI clients. It never asks for IRS accounts or Social Security numbers. Local tax parameters stay in a strict JSON format capped at 1 MiB with 0600 POSIX permissions, discarding identifying records such as names, employer IDs, and banking details.
The engine makes zero runtime network calls. However, data entered into cloud-hosted MCP clients travels to the respective model provider. For sensitive personal finances, use the offline command-line workflow directly without involving language models.
What it helps with
- Estimate federal income tax liabilities under TY2024–TY2026 rules
- Compare standard deductions against itemized expenses to choose the best option
- Determine estimated quarterly tax payments for freelancers and 1099 contractors
- Check eligibility limits for child tax credits and earned income relief
Example prompts for the agent
- Estimate my federal taxes for $130k income, married filing jointly, with two kids
- Compare state income tax amounts between California and Texas on $190k earnings
- I make $85k as a sole proprietor: what are my estimated quarterly payments?
How to install irs-taxpayer
Platform CLI
claude mcp add irs-taxpayer -- npx -y irs-taxpayer-mcpPlatform CLI
codex mcp add irs-taxpayer -- npx -y irs-taxpayer-mcpConfig file
{
"mcpServers": {
"irs-taxpayer": {
"command": "npx",
"args": [
"-y",
"irs-taxpayer-mcp"
]
}
}
}Config file
{
"servers": {
"irs-taxpayer": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"irs-taxpayer-mcp"
]
}
}
}Platform CLI
gemini mcp add irs-taxpayer npx -y irs-taxpayer-mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about irs-taxpayer
How to install irs-taxpayer in Claude Code?
Run claude mcp add irs-taxpayer -- npx -y irs-taxpayer-mcp in your terminal. Restart your assistant to make the tax calculation tools available.
Does irs-taxpayer require an SSN or IRS account?
No, it does not use IRS logins, SSNs, personal identities, or banking credentials. Calculations depend strictly on anonymous numeric inputs.
How does irs-taxpayer handle data privacy?
The local server runs calculations entirely on your machine without external calls. When using cloud models, prompts travel to model providers, so fully offline estimation should rely on the direct irs-taxpayer-mcp plan command.
