GAP-L1-P0-mcp-spec-2025-11-25

Current state

schema/examples/compute/mcp-transports/streamable-http.yaml records specVersion: "2025-03-26". The MCPTransport NodeKind only carries kind/specUrl/specVersion. There is no enumeration of MCP spec revisions, and no notion of feature deltas across revisions (e.g. elicitation, structured tool output, resource links, OAuth Resource Server classification, removal of JSON-RPC batching, mandatory MCP-Protocol-Version header).

Desired state

Schema models MCP spec revisions as first-class data:

• New NodeKind MCPSpecRevision with attributes revisionDate (iso-date), status (enum<live,deprecated,draft>), successorOf (ref<MCPSpecRevision>).
• Edge MCPTransport speaks_revision MCPSpecRevision (N:N) carrying since, until.
• MCPFeature NodeKind enumerating elicitation, structured-tool-output, resource-links, oauth-resource-server, protocol-version-header, jsonrpc-batching (deprecated 2025-06-18), _meta-field, completion-context, title-field.
• Edge MCPSpecRevision adds_feature / removes_feature MCPFeature.
• Existing streamable-http.yaml example updated to reference both 2025-06-18 and 2025-11-25 revisions.

Evidence

• https://modelcontextprotocol.io/specification (links to schema/2025-11-25/schema.ts)
• https://modelcontextprotocol.io/specification/2025-06-18/changelog (full 2025-03-26 → 2025-06-18 delta)
• C:/work/v6/graph/schema/examples/compute/mcp-transports/streamable-http.yaml

Propagation status

• Level 1 (real-world vs graph): in-progress
• Level 2 (graph vs docs): not-started — 02-node-kinds/transport.md and coverage-checklist.md rows must add MCPSpecRevision / MCPFeature
• Level 3 (qa vs docs): not-applicable
• Level 4–7: cascade once Level 1+2 land

Propagation chain

• Level 1: add NodeKinds + edges to ontology-schema.yaml; add 4 example revision files (2024-11-05, 2025-03-26, 2025-06-18, 2025-11-25); add 9 feature example files.
• Level 2: update transport.md + 03-edge-kinds.md + coverage-checklist row "MCP-Transport (sibling concept; not a layer)"; resolves OpenQuestion oq:industry-standard-cross-protocol-tool-call-streaming partially.

Notes

This is the single highest-impact L1 gap because MCP is the primary integration surface and the spec evolved twice since the catalog was authored.

Resolution (2026-04-28)

Closed via lighter-weight modeling than originally proposed: instead of introducing MCPSpecRevision and MCPFeature NodeKinds, MCP spec evolution is captured as:

• MCPTransport.specRevisions: list<string> and MCPTransport.currentSpecRevision: string (declared in ontology-schema.yaml, documented in 02-node-kinds/transport.md).
• Six new Capability entries representing the 2025-06-18 / 2025-11-25 deltas: capability:mcp-elicitation, capability:mcp-structured-tool-output, capability:mcp-resource-links, capability:mcp-oauth-resource-server, capability:mcp-protocol-version-header, capability:mcp-no-jsonrpc-batching.
• CapabilitySupport bindings record per-AgentRuntimeImpl support level (full/partial/none) with evidence sources.
• The transport YAML examples (stdio.yaml, streamable-http.yaml) list all four published revisions.

Propagation chain delivered:

• Level 1: schema/ontology-schema.yaml (MCPTransport attrs) + 6 capability YAMLs + 2 transport YAML updates + ~9 CapabilitySupport YAMLs (claude-code/cursor/opencode × elicitation/structured/resource-links).
• Level 2: 02-node-kinds/transport.md rewritten with the spec-revision-history section.
• Level 3+: not applicable (qa skeletons inert).