GrantLink offers a conventional, read-only REST API for stable resource integrations and a separate MCP server for model-led workflows. They share product data—not protocols or contracts.
The service is deployed, but API traffic is globally default-off. Access remains subject to organization policy and data-readiness checks. The public reference describes the contract; it does not promise access or a credential policy.
Two surfaces, deliberately optimized for different clients
Choose by consumer and workflow. Neither surface replaces, wraps, or proxies the other.
REST API v1
Best for
Services, data pipelines, reporting exports, and generated clients that need stable resources and ordinary HTTP behavior.
Authentication
Delegated Clerk OAuth authorization code with PKCE. Every operation requires user:org:read and grantlink:read; the selected organization comes only from the verified token.
Capabilities
Twelve GET operations cover organization settings, accounting availability, grants, canonical financial positions, effective transactions, funders, initiatives, and reporting cycles.
MCP-capable assistants that should choose purpose-built GrantLink tools while helping a user investigate or complete a workflow.
Authentication
Clerk OAuth with organization selection and user:org:read. Tool handlers enforce their own plan, data-readiness, and—where required—current organization-admin checks.
Capabilities
Curated tools expose account setup, search, portfolio and reporting context, financial diagnostics, and one explicit preview/apply workflow for GrantLink expense matching.
GrantLink can reuse domain policy and cohesive read logic behind the scenes without coupling either public contract to the other.
Protocol
REST APIVersioned JSON resources and HTTP status semantics
MCPMCP tools, prompts, resources, and JSON-RPC semantics
OAuth scopes
REST APIuser:org:read + grantlink:read
MCPuser:org:read
Gateway
REST APIDedicated public API gateway and closed operation allowlist
MCPDedicated MCP gateway with separate read and write controls
Quotas
REST APIREST-specific rate policy and response headers
MCPMCP-specific transport and tool controls
Failure domain
REST APIIsolated API deployment and RFC 9457 problems
MCPIsolated MCP deployment and protocol-native tool errors
Connect an MCP-capable client
Use Streamable HTTP and let the client follow GrantLink’s OAuth discovery. After the user signs in and selects an organization, the client can discover the current tool catalog withtools/list.
1
Set the server URL
Point a compatible client at https://grantlink.app/mcp using Streamable HTTP.
2
Complete delegated OAuth
GrantLink uses Clerk OAuth with PKCE. The user signs in, consents to user:org:read, and selects the organization the client may access.
3
Discover and call tools
The server publishes model-oriented descriptions and schemas at runtime so the client can choose from the currently supported tools.
The REST reference is generated from GrantLink’s checked-in OpenAPI snapshot. For access, client registration, or rollout questions, contact GrantLink before planning a production integration.