Snapshot: 2026-10-25. This matrix records implemented scope, assertion locators and qualified evidence, not a blanket MCP compliance verdict. The integration gate passed final QA with 423 tests and 2,116 assertions; qualified build, e2e and package evidence is recorded separately in integration-status.md. Counts do not prove every normative clause or deployment. No stale missing-export or mandatory-OAuth blocker applies to the current package.
| Surface | Revision/source | Maturity | Applicability |
|---|---|---|---|
| MCP core | 2026-07-28 | Released | Stateless Streamable HTTP client/server |
| Legacy MCP client | 2025-11-25, 2025-06-18, 2025-03-26, historical 2024-11-05 negotiation | Compatibility | Initialize/session path; no claim of removed HTTP+SSE transport support |
| Legacy MCP server | 2025-11-25, 2025-06-18, 2025-03-26 | Gated compatibility | Opt-in implemented; session affinity required; final scoped independent legacy approval |
| Tasks | 2026-07-28, b3d28aceaa6d49f5f92258e3d06b61ad6f111e84 | Stable upstream | Opt-in; tools/call only; durable host services required |
| Skills | stable, c1aa87e4c381c82b99aa37471d0eae4ab50f9985 | Stable upstream | Core 2026-07-28+; verification is not activation |
| Apps | 2026-01-26, 266a9e3b70dbd4a4f0546dda95da2a2c1a8be4b7 | Stable upstream | Explicit host bridge/support/presentation gate; renderer remains host-owned |
| Interchange | Installed @intx packages 0.5.0 | Executable integration baseline | Actual ToolBundle, credential and Agent contracts, not fabricated upstream APIs |
| MCP SDK | 1.30.1, development only | Legacy interoperability oracle | Does not certify 2026 behavior |
All three extensions are disabled by default. Stable upstream does not mean every
host supports them. No /v2 MCP methods, extension identifiers or protocol names
are introduced. Actual experimental additions require an unstable_ local API,
source pin and migration policy. The Apps UI protocol revision is independent of
the core MCP revision.
Claude Code documentation describes a 2026 runtime and task public beta on CLI 2.1.304+ with runtime, provider and surface restrictions. This is not evidence for universal Claude Desktop/web/CLI support. Blank community-matrix cells are not positive support evidence.
C = standalone client; S = server; IC/IS = Interchange consumption/exposure. The listed suites provide scoped evidence. Core F1–F11, auth neutral isolation, Apps gating and large Skills bounds have reported independent approvals. Legacy has final scoped independent approval; final reconciled QA passed. Clauses without a dedicated exhaustive mapping remain unverified for full clause coverage, not “missing tests” or “missing implementation.”
| ID | Normative clause / requirement | Role / applicability | Current evidence locator | Qualification |
|---|---|---|---|---|
| C01 | Basic: JSON-RPC envelopes, required per-request _meta | C/S, modern | src/protocol/protocol.test.ts; src/client/contracts.test.ts; src/server/server.test.ts | Scoped suite evidence; full clause coverage not certified |
| C02 | Versioning: supported revision and no invented version | C/S | src/protocol-2026.test.ts; src/server/server.test.ts; src/server/legacy.test.ts | Scoped suite evidence; full clause coverage not certified |
| C03 | HTTP sending: POST per message, Accept JSON + SSE, one request/notification | C/S | src/client.test.ts; src/server/server.test.ts; src/server/review-regressions.test.ts | Scoped suite evidence; full clause coverage not certified |
| C04 | HTTP security: invalid Origin rejected with 403 | S | src/server/server.test.ts (Origin/auth/header/malformed requests) | Scoped suite evidence; full clause coverage not certified |
| C05 | HTTP metadata: method/name/version headers match body, encoding and custom primitive headers | C/S | src/protocol/headers-codec.test.ts; src/client/review-regressions.test.ts | Scoped suite evidence; full clause coverage not certified |
| C06 | HTTP receiving: JSON/SSE, notifications scoped to request, no independent server request | C/S | src/client/contracts.test.ts; src/client/review-regressions.test.ts; src/server/review-regressions.test.ts | Scoped suite evidence; full clause coverage not certified |
| C07 | HTTP backward compatibility: discovery fallback but not auth/rate-limit/server failures | C, legacy | src/protocol-2026.test.ts; src/client/review-regressions.test.ts F8; e2e/sdk-transport.test.ts | Scoped suite evidence; full clause coverage not certified |
| C08 | Discovery: truthful version/capability advertisement, no modern sessions | C/S | src/server/server.test.ts (real client and loopback); e2e/protocol-2026.test.ts | Scoped suite evidence; full clause coverage not certified |
| C09 | Tools: schema-valid input/output, content, errors, unique catalog names | C/S/IC/IS | src/protocol/protocol.test.ts; src/server/providers.test.ts; src/client.test.ts | Scoped suite evidence; full clause coverage not certified |
| C10 | Prompts, resources, completion: feature-specific shapes, cursors and capabilities | C/S | src/protocol-2026.test.ts; src/protocol/protocol.test.ts; src/server/providers.test.ts | Scoped suite evidence; full clause coverage not certified |
| C11 | Caching: cache fields; authenticated cache isolation | C/S/IC/IS when caching | e2e/protocol-2026.test.ts; src/interchange/client/catalog.test.ts (host cache policy remains deployment-specific) | Scoped suite evidence; full clause coverage not certified |
| C12 | MRTR supported requests: only tools/call, prompts/get, resources/read permit input_required | C/S | src/protocol/protocol.test.ts; src/client/review-regressions.test.ts F2/F3 | Scoped suite evidence; full clause coverage not certified |
| C13 | MRTR client workflow: opaque latest requestState, original params, fresh ID | C/IC | src/protocol-2026.test.ts; src/interchange/client/continuation.test.ts | Scoped suite evidence; full clause coverage not certified |
| C14 | Elicitation: explicit form/URL support, validated responses, no implicit consent | C/S/IC/IS when opted in | src/client/review-regressions.test.ts F9; src/extensions/host.test.ts; src/interchange/client/projection.test.ts | Scoped suite evidence; full clause coverage not certified |
| C15 | Progress: request-local progress only | C/S | src/client/review-regressions.test.ts F11; src/server/server.test.ts | Scoped suite evidence; full clause coverage not certified |
| C16 | Cancellation: modern HTTP stream closure signals cancellation, no cancelled notification | C/S | src/client/review-regressions.test.ts F5; src/server/server.test.ts; src/server/legacy.test.ts | Scoped suite evidence; full clause coverage not certified |
| C17 | Subscriptions: negotiated filters, only allowed change notifications, terminal complete result | C/S when provided | src/client/review-regressions.test.ts F7/F11; src/server/review-regressions.test.ts | Scoped suite evidence; full clause coverage not certified |
| C18 | Authorization: protected-resource auth, challenge and operation authority | S/IS protected endpoints | src/auth/security.test.ts; src/auth/flows.test.ts; src/server/server.test.ts; e2e/interchange.test.ts | Guarded/neutral auth approved; stock dependency limits remain |
| C19 | AS discovery: issuer exactness, resource binding, PKCE, registration policy | C/hub OAuth | src/oauth-discovery.test.ts; src/auth/security.test.ts; src/auth/review-regressions.test.ts | Guarded/neutral auth approved; stock dependency limits remain |
| C20 | Deprecated features | All | Explicit modern non-goals; legacy ping/cancellation are revision-scoped | Scoped exclusions; see legacy-server.md |
| T01 | Tasks Capability Negotiation / Supported Methods: opt-in each request, tools/call only, missing capability error | C/S/IC/IS tasks | src/server/extensions.test.ts; src/protocol/protocol.test.ts | Scoped suite evidence; full clause coverage not certified |
| T02 | Tasks Task Status: working/input_required/completed/failed/cancelled; completed tool error differs from JSON-RPC failed | C/S tasks | src/extensions/tasks/tasks.test.ts; src/client/review-regressions.test.ts F3 | Scoped suite evidence; full clause coverage not certified |
| T03 | Tasks get/update/cancel: taskId header and outstanding input keys | C/S tasks | src/extensions/tasks/tasks.test.ts; src/protocol/headers-codec.test.ts | Scoped suite evidence; full clause coverage not certified |
| T04 | Tasks durability + scope §§4,7: persist before handle; tenant/principal isolation, TTL, CAS and recoverable executor | S/IS tasks | src/extensions/tasks/tasks.test.ts; e2e/fixtures/packed-standalone.mjs | Scoped suite evidence; full clause coverage not certified |
| T05 | Scope §5: workflow correlation and truthful cooperative cancellation | IS tasks/workflows | src/interchange/server/accepted.test.ts; src/interchange/server/server.test.ts | Scoped suite evidence; full clause coverage not certified |
| K01 | Skills Capability Negotiation: resources capability, list/get; directoryRead only if declared | C/S skills | src/server/extensions.test.ts; src/interchange/client/skills.test.ts | Scoped suite evidence; full clause coverage not certified |
| K02 | Skills Skill Format / Resource Mapping: root SKILL.md, YAML name/description, name/path match, no scheme-only identity | S/IC skills | src/extensions/skills/skills.test.ts | Scoped suite evidence; full clause coverage not certified |
| K03 | Skills manifest integrity/security + scope §4: all file hashes, byte limits, origin and held-manifest binding | C/S/IC skills | src/extensions/skills/skills.test.ts; src/interchange/client/skills-large.test.ts; src/protocol/resource-bounds.test.ts | Independent authenticated-loopback/bounds approval, including 16 MiB |
| K04 | Scope §4 host activation: approval/provenance bound to context admission and all execution tools for acting window | IC skills | src/extensions/skills/verification-race.test.ts; src/extensions/skills/skills.test.ts | Scoped suite evidence; full clause coverage not certified |
| A01 | Apps Capability Negotiation / Tool-UI Linkage: opt-in, metadata preserved, app-only tools not model-visible | C/S/IC/IS UI metadata | src/interchange/client/apps.test.ts; src/extensions/host.test.ts | Scoped independent approval (74 tests + 6 probes); host renderer not certified |
| A02 | Apps UI Resource Format: ui:// and text/html;profile=mcp-app; host sandbox/CSP | S metadata; browser host excluded | src/extensions/host.test.ts; src/interchange/client/apps.test.ts (actual renderer is host-owned) | Scoped independent approval (74 tests + 6 probes); host renderer not certified |
| I01 | Scope §§2,5: real ToolBundle dispatch, explicit selected exposure, execution rechecks grants | IC/IS | e2e/interchange.test.ts; src/interchange/server/server.test.ts | Scoped suite evidence; full clause coverage not certified |
| I02 | Scope §§2,5: synchronous stored catalogs, credential consumer identity and origin pinning, destructive ask floor | IC | src/sidecar-bundle.test.ts; src/tool.test.ts; src/hub/discover.test.ts | Scoped suite evidence; full clause coverage not certified |
| I03 | Scope §5: preserve structured/binary/private detail and truthful lifecycle projection | IC | src/interchange/client/projection.test.ts; src/interchange/client/integration.test.ts | Scoped suite evidence; full clause coverage not certified |
| P01 | Scope §2: four entries, historical facades, declarations and runtime dependency isolation | Package | e2e/package.test.ts; installed tarballs on Bun 1.4.2 / Node 24.22.1 | Installed boundary passes; latest counts in integration-status.md |
The server implements opt-in 2025-11-25/06-18/03-26 Streamable HTTP sessions; modern remains stateless. See legacy deployment and limits. Legacy now has final scoped approval: 50 tests / 319 assertions plus 5 independent tests / 63 assertions, as reported by the director. Both header and shutdown repairs are closed. This is separate from the approved core F1–F11 repairs and does not substitute for final reconciled QA. No removed HTTP+SSE or resumption support is claimed.
Apps advertisement requires explicit host bridge support, sandbox renderer, CSP enforcement, authenticated bridge and presentation. Metadata-only handling never advertises Apps. The host still supplies the actual renderer and enforces its security properties; the library's gate is not a deployed-browser audit. Skills verification supports bounded 16 MiB decoded resources; independent review exercised actual authenticated loopback and all bounds. Verification is not approval to admit context or execute code.
The verified Skills adapter declines dynamic manifests, as permitted by the pinned specification. It requires complete resource reads with exactly one matching text/blob item; resource-read MRTR is unsupported by that adapter. These are explicit supported-shape limits, not a reopening of the approved resource bounds or a claim that dynamic consumption is mandatory.
- CL11479 — external OAuth-core defects: stock 0.3.0 token/profile/storage requires refresh tokens; stock token POST follows redirects and exposes raw response errors; authorize extras can overwrite state/PKCE. Guarded MCP sessions avoid those paths but do not fix stock OAuth-core. Stock hub DCR-only selection and present-but-unadvertised issuer handling are additional documented integration limits, not silently added issue acceptance criteria. Resource exchange/refresh propagation already exists upstream; the local config omission was fixed. See guarded auth and companion limits.
- CL11480 — external credential-http defects: old harness/types peer ranges block the pinned full hub install; Request+init semantics and insecure configured destination schemes also need upstream correction. Neutral installs pass and must not be conflated with this optional host failure.
- Host obligations: trusted identity/grants, cryptographic verification or introspection, credential storage, callback/registration setup, explicit selected bindings, durable recoverable executors, session affinity, skill approval and context lifecycle, and Apps renderer/bridge security. These are injected application responsibilities, not invented missing library features.
- Unverified deployments/clauses: production DB transactions, live OAuth services and callback deployment, distributed lifecycle durability, browser sandbox enforcement, and exhaustive revision-by-clause coverage require their own evidence. No 100% conformance or production certification is asserted.
bun run check, bun run test:e2e, and the serial installed-package gate provide
complementary evidence; exact commands, versions, counts and exit codes are in
integration-status.md. Independent Apps (74 tests plus
6 probes), authenticated large-Skills, core and auth approvals are reported by
the director; they are not relabeled as fresh executions by this docs lane.