Model Context Protocol

Exposing a checkpoint as a resource

An MCP server that produces or stores checkpoints can list each one as a resource:

• uri: any URI the server controls, for example checkpoints://tasks/1412/latest.
• mimeType: application/vnd.opencheckpoint+json.
• The resource contents are the checkpoint document as text.

A client or host that restores the checkpoint follows the restoration procedure. A checkpoint fetched through MCP is still untrusted input.

Referencing MCP resources

A checkpoint resource can carry an MCP resource URI directly in uri, including custom schemes. Use resolver to hint which server can resolve it:

{
  "id": "r-design-doc",
  "kind": "document",
  "uri": "docs://projects/atlas/design.md",
  "resolver": { "protocol": "mcp", "hint": { "server": "docs" } },
  "revision": "2026-10-20T11:00:00Z"
}

The hint names a server, never credentials. The destination resolves the URI through its own MCP connections, with its own authorization.

Mapping

MCP	OpenCheckpoint
Resource.uri, mimeType, size	resource.uri, media_type, size
Annotations.lastModified	resource.revision or observed_at
input_required result	an operation with kind: input, status: awaiting
Tasks extension status working, input_required, completed, failed, cancelled	task.status and operation status, where the meanings match
_meta reverse-DNS keys	extensions reverse-DNS keys (same convention)