MCP connector for Claude

Funding Finder: federal grants, in plain words.

Small Business Funding Finder searches the live federal grant listings on Grants.gov from inside Claude. Ask for grants open to small businesses, nonprofits, tribes or local governments, narrow by topic, agency and deadline, open any listing in full, and decode who is actually eligible. Every result links to its official Grants.gov listing, where every detail should be confirmed before applying.

Connector URL

https://mcp.modernmustardseed.com/funding-finder

Streamable HTTP. No sign-in. Every tool is read-only.

This product uses the Grants.gov API but is not endorsed or certified by the U.S. Department of Health and Human Services.

Connect it

In Claude, open Settings, then Connectors.
Choose Add custom connector, paste https://mcp.modernmustardseed.com/funding-finder, and save. No account or key is needed.
In a chat, ask about grants. Claude calls the tools when the question needs them.

In Claude Code: claude mcp add --transport http funding-finder https://mcp.modernmustardseed.com/funding-finder

Try these

“Find federal grants open to small businesses for rural energy efficiency, and tell me which ones close first.”
“Which federal grants open to 501(c)(3) nonprofits close in the next 30 days? Group them by agency.”
“Pull up Grants.gov opportunity NOAA-NMFS-AK-2026-33268 and explain in plain words who is eligible and what the award range is.”

The tools

search_grants

Search federal grants

Searches live Grants.gov listings by keyword and filters: applicant type (small business, 501(c)(3) nonprofit, tribe, city and more), category, funding instrument, agency (code or name, departments expand to their sub-agencies), assistance listing number, status (posted, forecasted or both) and close date range. Returns each match with its number, title, agency, posted and close dates, days left and the official listing link.

Inputs: keyword, eligibility, include_unrestricted, categories, instruments, agency, assistance_listing, status, closes_after, closes_before, sort, limit, offset (all optional).

get_grant

Get a grant listing

Returns one listing in full: status, agency, dates (or forecast dates), award ceiling and floor, total funding, expected awards, cost sharing, every applicant type in plain words, the additional eligibility text, instruments, categories, assistance listings, the agency contact, the description and the document folders.

Inputs: opportunity_id or opportunity_number; detail: "summary" (default) or "full".

grants_closing_soon

Grants closing soon

Lists posted opportunities whose deadline falls in the next 1 to 120 days (30 by default), soonest first, with days left, using the same filters as search_grants.

Inputs: within_days, keyword, eligibility, include_unrestricted, categories, instruments, agency, assistance_listing, limit (all optional).

eligibility_explainer

Explain eligibility codes

Decodes Grants.gov applicant eligibility codes: the official label, what it means in plain words, who counts, what to watch for, and the source for each. With no input it returns all 17 codes.

Inputs: codes (such as "23" or "12") and or applicant_types (such as small_business), both optional.

Eligibility codes

Grants.gov marks each listing with the applicant types that may apply. The filter keys below are what search_grants accepts. Labels as of 2026-10-11.

00state_government
A state government or one of its agencies.
01county_government
A county, borough or parish government.
02city_or_township_government
A city, town, township or village government.
04special_district_government
A local government unit set up for one purpose, such as water, fire, transit, parks or a port.
05independent_school_district
A public school district.
06public_higher_education
A public college or university.
07tribal_government
The government of a federally recognized tribe.
08public_housing_authority
A public housing authority or a tribally designated housing entity.
11tribal_organization
A tribal organization that is not itself a federally recognized tribal government.
12nonprofit_501c3
A charity with an IRS 501(c)(3) determination.
13nonprofit_other
A nonprofit without 501(c)(3) status, such as a 501(c)(4) or (c)(6) association.
20private_higher_education
A private college or university.
21individual
A person applying in their own name.
22for_profit_not_small
A for-profit company that is larger than the SBA small business size standard for its industry.
23small_business
A for-profit business that meets the SBA small business size standard for its industry.
25others
Someone not in the standard list. The listing text says who.
99unrestricted
Open to any type of applicant on this list, subject to the listing text.

When you filter by applicant type, Unrestricted (99) listings are included by default because they are open to any applicant type. Set include_unrestricted to false to leave them out.

Data sources and licenses

Grants.gov public API (search2 and fetchOpportunity at api.grants.gov, no key required), run by the U.S. Department of Health and Human Services. Used under the Grants.gov API terms and conditions, which permit searching, displaying and retrieving grants data, require the notice above, and forbid modifying or misrepresenting the content. We show listing text as Grants.gov publishes it, decode HTML only, and link every result to its official listing.
Eligibility explanations are written by us from the Grants.gov code labels, with citations to the SBA size standards (13 CFR Part 121), the Internal Revenue Code section 501(c)(3), and the Bureau of Indian Affairs list of federally recognized tribes. They are informational, not legal advice.
SBA programs are not included. We looked for an official, openly licensed SBA data source to search programs from. SBA program pages have no public API, and the SBIR.gov solicitations API refused our requests (HTTP 403) on 2026-10-11. SBA grants that are posted on Grants.gov appear in search results like any other listing.

Limits

Searches are cached for 10 minutes, listings for 60 minutes and the agency list for 6 hours. Every result carries cached and fetched_at so you can tell how fresh it is.
To stay polite to Grants.gov, we send at most 30 requests a minute from each server instance and 4,000 a day across all users, and fetch any one listing fresh at most 3 times in 10 minutes. Saved results still answer when a limit is reached.
Each tool also has a per-minute limit on each server instance, and the connector accepts 10,000 calls a day across all users. Over a limit, the tool says so and gives the time to try again.
Search results return up to 50 at a time; use offset for the next page. Descriptions are capped at about 1,500 characters, or 6,000 with detail “full”.
Close-date filters and closing_soonest sorting cover every posted listing on Grants.gov (one request reads up to 1,000, and fewer than that are posted). Listings with no close date, or the far-future placeholder Grants.gov uses for open-ended listings, are left out of close-date filters.

Troubleshooting

“No agency with current listings matches”: The agency has nothing posted right now, or the name did not match. The message lists every agency with current listings and its code.
“Grants.gov did not answer” or “is having trouble”: The Grants.gov API was slow or down. We retry once before reporting it. Try again in a minute.
A listing shows a close date in 2099: Grants.gov uses that date for open-ended listings. The result says so; the real deadline, if any, is in the listing text.

For reviewers

No account, key or setup is needed. Add the connector URL above, then:

search_grants with keyword energy efficiency and eligibility ["small_business"].
grants_closing_soon with within_days 30.
search_grants with agency HHS, sort newest, limit 5.
get_grant with an opportunity_id from any result above.
eligibility_explainer with codes ["23", "99"].
Errors: get_grant with opportunity_id 99999999, and search_grants with closes_after 2026-13-40, each return a specific message.

Support and security

Questions, problems and security reports go to sarah@modernmustardseed.com. A machine-readable contact is at /.well-known/security.txt. How we handle data is in the privacy policy.