Plinth US Grants Data

A JSON API over the entire US grantmaking universe — about 205,000 grantmaking foundations and 17.9 million grants, read from public IRS Form 990, 990-EZ and 990-PF e-file filings and the IRS Business Master File. The funder-grantee graph traverses in both directions: filter by funder_id for everything a foundation funded, or by recip_id for every funder behind a nonprofit. Offers REST endpoints for grants, organization profiles, an IRS compliance and OFAC screen, an ad-hoc read-only SQL endpoint over a 31-table warehouse, and a hosted OAuth 2.1 MCP connector for AI agents. Entity resolution is free and unmetered. Published by Plinth, trading name of Time to Spare Ltd (UK Companies House 11530023), which also operates plinth.org.uk in the UK.

Plinth US Grants Data publishes 5 APIs on the APIs.io network, including Analyze API, Grants API, Organizations API, and 2 more. Tagged areas include Philanthropy, Grants, Nonprofits, Foundations, and IRS 990.

The Plinth US Grants Data catalog on APIs.io includes 1 Spectral governance ruleset.

Plinth US Grants Data’s developer surface includes documentation, API reference, getting-started guide, support, pricing, signup flow, authentication, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub
62.3/100 strong Agent 60/100 agent ready Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0
5 APIs 2 MCP Servers
PhilanthropyGrantsNonprofitsFoundationsIRS 990Open DataGovernment SpendingResearchAgentsRESTJSONMCPSQL

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0
Composite quality — 62.3/100 · strong
Contract Quality 12.5 / 21
Developer Ergonomics 11.1 / 17
Commercial Clarity 13.0 / 17
Operational Transparency 1.2 / 11
Governance 5.3 / 10
Discoverability 7.9 / 9
Regulatory Posture 11.4 / 15
Agent readiness — 60/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 3 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Government & Public Sector regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/plinth-us-grants-data: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 5

Individual APIs this provider publishes, each with its own machine-readable definition.

Plinth US Grants Data Analyze API

Plain-English questions answered with SQL the service writes itself.

Plinth US Grants Data Grants API

The funder-grantee graph: grants, funders, recipients and aggregates.

Plinth US Grants Data Organizations API

Per-organization profiles, financials and IRS compliance facets.

Plinth US Grants Data Resolve API

Turn an organization name into an EIN and a canonical URL. No key required.

Plinth US Grants Data SQL API

Ad-hoc read-only SQL over the warehouse. Paid keys only.

MCP Servers 2

Model Context Protocol servers that expose these APIs to AI agents.

mcp

MCP SERVER

plinth-us-grants-data-mcp.yml

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Plinth Us Grants Data Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Plinth Us Grants Data Rate Limits

0 limits

RATE LIMITS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Plinth US Grants Data API Rules

10 rules · 9 errors 1 warnings

SPECTRAL

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Plinth Us Grants Data Authentication

apiKey/oauth2 · 2 schemes

SECURITY

Plinth Us Grants Data Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Plinth Us Grants Data Vulnerability Disclosure

security.txt · contact published

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Plinth Us Grants Data Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 SignUp
SignUp
 Login
Login

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer
MCPServer
 MCPServer
MCPServer
 WellKnown
WellKnown
 AgentSkill
AgentSkill

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Conformance
Conformance
 Lifecycle
Lifecycle
 Vocabulary
Vocabulary

Build 1

SDKs, sample code, and the tooling you integrate with

Packages
Packages

Access & Security 6

Authentication, authorization, and security posture

Authentication
Authentication
 OAuthScopes
OAuthScopes
 Security
Security
 VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity
 SecurityTxt
SecurityTxt

Operate 2

Status, limits, changes, and where to get help

Support
Support
 Contact
Contact

Commercial 4

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy
 Plans
Plans

Other 2

Properties that don't map to a standard resource type

Overlay
Overlay
 APICatalog
APICatalog

Source (apis.yml)

apis.yml Raw ↑ 
name: Plinth US Grants Data
description: 'A JSON API over the entire US grantmaking universe — about 205,000 grantmaking foundations and 17.9 million
  grants, read from public IRS Form 990, 990-EZ and 990-PF e-file filings and the IRS Business Master File. The funder-grantee
  graph traverses in both directions: filter by funder_id for everything a foundation funded, or by recip_id for every funder
  behind a nonprofit. Offers REST endpoints for grants, organization profiles, an IRS compliance and OFAC screen, an ad-hoc
  read-only SQL endpoint over a 31-table warehouse, and a hosted OAuth 2.1 MCP connector for AI agents. Entity resolution
  is free and unmetered. Published by Plinth, trading name of Time to Spare Ltd (UK Companies House 11530023), which also
  operates plinth.org.uk in the UK.'
image: https://data.useplinth.com/plinth-logo.svg
url: https://plinth-us-grants-data.apievangelist.com/apis.yml
created: '2026-08-13'
modified: '2026-08-14'
specificationVersion: '0.21'
tags:
- Philanthropy
- Grants
- Nonprofits
- Foundations
- IRS 990
- Open Data
- Government Spending
- Research
- Agents
- REST
- JSON
- MCP
- SQL
apis:
- aid: plinth-us-grants-data:plinth-us-grants-data-analyze-api
  name: Plinth US Grants Data Analyze API
  description: Plain-English questions answered with SQL the service writes itself.
  humanURL: https://data.useplinth.com/developers
  baseURL: https://data.useplinth.com/api
  tags:
  - Analyze
  properties:
  - type: OpenAPI
    url: openapi/plinth-us-grants-data-analyze-api-openapi.yml
  - type: Documentation
    url: https://data.useplinth.com/developers
  - type: LLMsTxt
    url: llms/plinth-us-grants-data-llms.txt
  - type: LLMsTxt
    url: https://data.useplinth.com/llms.txt
  - type: ToolCrosswalk
    url: mcp/plinth-us-grants-data-tool-crosswalk.yml
  - type: RateLimits
    url: rate-limits/plinth-us-grants-data-rate-limits.yml
  - type: ErrorCatalog
    url: errors/plinth-us-grants-data-problem-types.yml
  - type: DataModel
    url: data-model/plinth-us-grants-data-data-model.yml
  - type: Conventions
    url: conventions/plinth-us-grants-data-conventions.yml
  - type: SpectralRules
    url: rules/plinth-us-grants-data-spectral.yaml
  - type: SpectralRules
    url: https://data.useplinth.com/spectral/grants-api.yaml
- aid: plinth-us-grants-data:plinth-us-grants-data-grants-api
  name: Plinth US Grants Data Grants API
  description: 'The funder-grantee graph: grants, funders, recipients and aggregates.'
  humanURL: https://data.useplinth.com/developers
  baseURL: https://data.useplinth.com/api
  tags:
  - Grants
  properties:
  - type: OpenAPI
    url: openapi/plinth-us-grants-data-grants-api-openapi.yml
  - type: Documentation
    url: https://data.useplinth.com/developers
  - type: LLMsTxt
    url: llms/plinth-us-grants-data-llms.txt
  - type: LLMsTxt
    url: https://data.useplinth.com/llms.txt
  - type: ToolCrosswalk
    url: mcp/plinth-us-grants-data-tool-crosswalk.yml
  - type: RateLimits
    url: rate-limits/plinth-us-grants-data-rate-limits.yml
  - type: ErrorCatalog
    url: errors/plinth-us-grants-data-problem-types.yml
  - type: DataModel
    url: data-model/plinth-us-grants-data-data-model.yml
  - type: Conventions
    url: conventions/plinth-us-grants-data-conventions.yml
  - type: SpectralRules
    url: rules/plinth-us-grants-data-spectral.yaml
  - type: SpectralRules
    url: https://data.useplinth.com/spectral/grants-api.yaml
- aid: plinth-us-grants-data:plinth-us-grants-data-organizations-api
  name: Plinth US Grants Data Organizations API
  description: Per-organization profiles, financials and IRS compliance facets.
  humanURL: https://data.useplinth.com/developers
  baseURL: https://data.useplinth.com/api
  tags:
  - Organizations
  properties:
  - type: OpenAPI
    url: openapi/plinth-us-grants-data-organizations-api-openapi.yml
  - type: Documentation
    url: https://data.useplinth.com/developers
  - type: LLMsTxt
    url: llms/plinth-us-grants-data-llms.txt
  - type: LLMsTxt
    url: https://data.useplinth.com/llms.txt
  - type: ToolCrosswalk
    url: mcp/plinth-us-grants-data-tool-crosswalk.yml
  - type: RateLimits
    url: rate-limits/plinth-us-grants-data-rate-limits.yml
  - type: ErrorCatalog
    url: errors/plinth-us-grants-data-problem-types.yml
  - type: DataModel
    url: data-model/plinth-us-grants-data-data-model.yml
  - type: Conventions
    url: conventions/plinth-us-grants-data-conventions.yml
  - type: SpectralRules
    url: rules/plinth-us-grants-data-spectral.yaml
  - type: SpectralRules
    url: https://data.useplinth.com/spectral/grants-api.yaml
- aid: plinth-us-grants-data:plinth-us-grants-data-resolve-api
  name: Plinth US Grants Data Resolve API
  description: Turn an organization name into an EIN and a canonical URL. No key required.
  humanURL: https://data.useplinth.com/developers
  baseURL: https://data.useplinth.com/api
  tags:
  - Resolve
  properties:
  - type: OpenAPI
    url: openapi/plinth-us-grants-data-resolve-api-openapi.yml
  - type: Documentation
    url: https://data.useplinth.com/developers
  - type: LLMsTxt
    url: llms/plinth-us-grants-data-llms.txt
  - type: LLMsTxt
    url: https://data.useplinth.com/llms.txt
  - type: ToolCrosswalk
    url: mcp/plinth-us-grants-data-tool-crosswalk.yml
  - type: RateLimits
    url: rate-limits/plinth-us-grants-data-rate-limits.yml
  - type: ErrorCatalog
    url: errors/plinth-us-grants-data-problem-types.yml
  - type: DataModel
    url: data-model/plinth-us-grants-data-data-model.yml
  - type: Conventions
    url: conventions/plinth-us-grants-data-conventions.yml
  - type: SpectralRules
    url: rules/plinth-us-grants-data-spectral.yaml
  - type: SpectralRules
    url: https://data.useplinth.com/spectral/grants-api.yaml
- aid: plinth-us-grants-data:plinth-us-grants-data-sql-api
  name: Plinth US Grants Data SQL API
  description: Ad-hoc read-only SQL over the warehouse. Paid keys only.
  humanURL: https://data.useplinth.com/developers
  baseURL: https://data.useplinth.com/api
  tags:
  - SQL
  properties:
  - type: OpenAPI
    url: openapi/plinth-us-grants-data-sql-api-openapi.yml
  - type: Documentation
    url: https://data.useplinth.com/developers
  - type: LLMsTxt
    url: llms/plinth-us-grants-data-llms.txt
  - type: LLMsTxt
    url: https://data.useplinth.com/llms.txt
  - type: ToolCrosswalk
    url: mcp/plinth-us-grants-data-tool-crosswalk.yml
  - type: RateLimits
    url: rate-limits/plinth-us-grants-data-rate-limits.yml
  - type: ErrorCatalog
    url: errors/plinth-us-grants-data-problem-types.yml
  - type: DataModel
    url: data-model/plinth-us-grants-data-data-model.yml
  - type: Conventions
    url: conventions/plinth-us-grants-data-conventions.yml
  - type: SpectralRules
    url: rules/plinth-us-grants-data-spectral.yaml
  - type: SpectralRules
    url: https://data.useplinth.com/spectral/grants-api.yaml
maintainers:
- FN: Plinth (Time to Spare Ltd)
  email: data@useplinth.com
  organizationName: Plinth (Time to Spare Ltd)
  url: https://www.useplinth.com
  X-twitter: useplinth
generated:
  by: apis.io/add
  model: claude-opus-4-8
  confidence: 97
  at: '2026-08-13T20:59:07.936Z'
common:
- type: MCPServer
  url: https://data.useplinth.com/api/connector/mcp
- type: MCPServer
  url: mcp/plinth-us-grants-data-mcp.yml
- type: Overlay
  url: overlays/plinth-us-grants-data-grants-api-overlay.yaml
- type: DeveloperPortal
  url: https://data.useplinth.com/developers
- type: Documentation
  url: https://data.useplinth.com/developers
- type: APIReference
  url: https://data.useplinth.com/developers
- type: GettingStarted
  url: https://data.useplinth.com/developers#auth
- type: Support
  url: https://data.useplinth.com/developers#governance
- type: Contact
  url: mailto:data@useplinth.com
- type: Pricing
  url: https://data.useplinth.com/pricing
- type: SignUp
  url: https://data.useplinth.com/account
- type: Login
  url: https://data.useplinth.com/account
- type: TermsOfService
  url: https://www.useplinth.com/terms
- type: PrivacyPolicy
  url: https://www.useplinth.com/privacy
- type: Authentication
  url: authentication/plinth-us-grants-data-authentication.yml
- type: OAuthScopes
  url: scopes/plinth-us-grants-data-scopes.yml
- type: Security
  url: security/plinth-us-grants-data-vulnerability-disclosure.yml
- type: VulnerabilityDisclosure
  url: security/plinth-us-grants-data-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/plinth-us-grants-data-domain-security.yml
- type: WellKnown
  url: well-known/plinth-us-grants-data-well-known.yml
- type: SecurityTxt
  url: well-known/plinth-us-grants-data-security.txt
- type: APICatalog
  url: well-known/plinth-us-grants-data-api-catalog.json
- type: Conformance
  url: conformance/plinth-us-grants-data-conformance.yml
- type: Lifecycle
  url: lifecycle/plinth-us-grants-data-lifecycle.yml
- type: Vocabulary
  url: vocabulary/plinth-us-grants-data-vocabulary.yml
- type: Plans
  url: plans/plinth-us-grants-data-plans-pricing.yml
- type: Packages
  url: packages/plinth-us-grants-data-packages.yml
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-08-14'
  status: enriched
  artifacts_added: 31
  pass: local-v1