generated: '2026-08-14'
method: searched
status: published
source: https://data.useplinth.com/connect
corroboration:
- https://data.useplinth.com/.well-known/apis.json
- https://data.useplinth.com/.well-known/oauth-protected-resource
- https://data.useplinth.com/.well-known/api-onboarding
deployment:
  mode: remote
  endpoint: https://data.useplinth.com/api/connector/mcp
  install: null
  package: null
  auth: oauth
  verified: probed
  probe: gated
  probe_prior: (prose)
  probe_why: RFC 9728 challenge on the MCP path only
  checked: '2026-09-11'
  source: claimed-backlog re-probe 2026-09-11
server:
  name: Plinth
  transport: streamable-http
  url: https://data.useplinth.com/api/connector/mcp
  human_url: https://data.useplinth.com/connect
  clients_documented:
  - Claude (claude.ai, desktop, mobile; self-serve on Pro/Max, admin-installed on Team/Enterprise)
  - ChatGPT
  - Microsoft 365 Copilot
  listings: []
  listings_note: Not found in the Claude Connector directory or the ChatGPT Apps directory as of 2026-08-14;
    installation is by pasting the custom-connector URL, which the /connect page walks through per client.
auth:
  methods:
  - oauth2
  oauth2:
    authorization_server: https://data.useplinth.com
    metadata: well-known/plinth-us-grants-data-oauth-authorization-server.json
    protected_resource_metadata: well-known/plinth-us-grants-data-oauth-protected-resource.json
    authorization_endpoint: https://data.useplinth.com/oauth/authorize
    token_endpoint: https://data.useplinth.com/oauth/token
    registration_endpoint: https://data.useplinth.com/oauth/register
    dynamic_client_registration: true
    grant_types:
    - authorization_code
    - refresh_token
    pkce: S256
    token_endpoint_auth_methods:
    - none
    scopes_supported:
    - plinth:read
    see: scopes/plinth-us-grants-data-scopes.yml
  human_in_the_loop: 'Yes, once. The provider''s own onboarding descriptor records maturity "console-only"
    and lists "No programmatic signup" as a gap: an agent can dynamically register a client and run PKCE,
    but a human must sign in at /account and hold a plan that includes the connector before consent can
    succeed.'
  plan_gate:
    required_plan: For consultants ($250/mo)
    evidence: Both the pricing page ("Plinth × Claude connector" appears only on the For consultants tier)
      and the onboarding descriptor ("the MCP connector" listed under the $250 plan) agree. The /connect
      page calls this "Plinth Pro".
tools:
  discovery: gated
  discovery_note: tools/list requires an OAuth bearer token (401 above), so the machine-readable tool
    list with real inputSchemas could NOT be captured. The three tools below are read from the provider's
    own /connect page, which describes each capability in prose. NAMES ARE DESCRIPTIVE, NOT VERBATIM —
    Plinth does not publish tool identifiers anywhere public, and llms.txt does not list them either.
    Do not treat these strings as callable tool names; an authenticated tools/list is the only way to
    get those. Descriptions are quoted from the provider.
  tool_count: 3
  tool_count_note: Three capabilities are documented; the live server may expose more.
  documented:
  - label: Search organizations
    category: resolve
    description: '"Find any funder or nonprofit across the universe — by name, state, or size."'
    source: https://data.useplinth.com/connect
  - label: Get a foundation dossier
    category: profile
    description: '"Pull Plinth''s analytical summary for one foundation: giving, causes, grantee network,
      outcomes, look-alikes."'
    source: https://data.useplinth.com/connect
  - label: Ask a foundation a question
    category: analysis
    description: '"Natural-language Q&A grounded strictly in that foundation''s own IRS filings."'
    source: https://data.useplinth.com/connect
crosswalk: mcp/plinth-us-grants-data-tool-crosswalk.yml