Specification notices

The adapter emits a structured information notice when an enabled MCP feature uses a Beta, draft, or experimental contract. A deprecation emits a warning instead. Each adapter instance emits a notice once for each code, feature, and revision. See the specification inventory for the authority, revision, and support status of each contract.

The local sink writes structured console notices to standard error. Set onNotice to use your logger. Set local: false to disable the local sink, including the callback. Set openTelemetry: true to emit the same notice through the host's registered OpenTelemetry Logs provider. Configure that provider in your application.

import { mcp } from "@mwillbanks/elysia-mcp-adapter";

const adapter = mcp({
  diagnostics: {
    specificationNotices: {
      local: false,
      openTelemetry: true,
    },
  },
});

A notice contains code, severity, featureId, revision, and sourceUrl. Deprecation warnings also include migration guidance. The codes are MCP_SPECIFICATION_PRE_RELEASE and MCP_SPECIFICATION_DEPRECATED. Both sinks use adapter catalog values. A sink failure leaves request handling intact. The adapter emits notices outside the MCP protocol and does not create an OpenTelemetry SDK or exporter.

DeprecationsCopy Anchor Link

Server Variants remains available for this release. A later minor can remove the opt-in. The adapter reports Roots and Sampling when it sends a validated input request, including in task replies and subscription updates.

See the upstream deprecations for the removal schedule. The inventory records which deprecations apply to the adapter.