Submit grant applications via Grants.gov System-to-System (S2S) Apply

Steps

1. Register your organization as an S2S applicant on Grants.gov and obtain the client certificate required for S2S web service authentication; S2S uses certificate-based mutual TLS, not API key authentication.
2. Use the Grants.gov S2S applicant web service (SOAP) to call GetOpportunityList or the newer REST search endpoint at https://api.grants.gov/v1/api/search2 to find the target funding opportunity and retrieve its applicationPackageId.
3. Download the application package schema using the S2S GetApplicationPackage web service call; the package defines the required forms (SF-424, project narrative, budget) in grantor-specified XML schemas.
4. Populate all required form schemas in XML, validate each against the package schema, and bundle them into a submission package; attach supporting documents as base64-encoded file attachments within the XML envelope.
5. Submit the package via the S2S SubmitApplication web service call using your client certificate for authentication; the service returns a trackingNumber that you use to monitor submission status.
6. Poll GetApplicationStatus with the trackingNumber until the status transitions from Received to Validated or Rejected; a Validated status means Grants.gov has accepted the package for forwarding to the awarding agency.