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Northstar Toolkit is the nonprofit data platform — every US nonprofit and foundation from IRS 990 filings, as free search, a developer API, and an MCP server for AI agents. The 990 base layer is free, and stays free.
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    Quickstart

    Your first call to the nonprofit data API in under a minute.

    1. Try it without a key

    Every endpoint works keyless with generous rate limits. Look up an organization by EIN:

    curl https://api.northstartoolkit.com/v1/organizations/86-0481941

    EINs are accepted with or without the hyphen. The response includes identity, the latest financial summary, people, and an index of every available filing — each record stamped with its tax year and source.

    2. Get a free key

    A free key lifts the rate limits. Create an account, open the Developer page in your workspace, and create a key. Then pass it as a bearer token:

    curl https://api.northstartoolkit.com/v1/organizations/86-0481941 \
      -H "Authorization: Bearer YOUR_API_KEY"

    3. Pull a full filing

    The flagship endpoint: the complete modeled 990 as JSON — header, revenue and expense line items, balance sheet, program accomplishments, and the compensation table.

    curl https://api.northstartoolkit.com/v1/organizations/86-0481941/filings/2023

    4. Search with financial filters

    Query primitives nobody else self-serves — filter every US nonprofit by state, category, and financials:

    curl "https://api.northstartoolkit.com/v1/organizations?state=TX&ntee_prefix=K&revenue_min=5000000"

    Or search semantically over missions and program text:

    curl "https://api.northstartoolkit.com/v1/search?q=youth+homelessness+housing+first"

    Next steps

    • Full API reference — every endpoint, parameter, and response schema
    • Use it from Claude — the MCP server wraps the same API for agents
    • Limits and the Builder tier — commercial use starts at $49/month

    A note on freshness: the IRS publishes e-filed returns on its own schedule, often a year or more after the fiscal year ends. Every record carries its tax year, form type, and ingest date so staleness is always self-describing — we don't promise freshness the data can't have.