[Not ready for merge] Serve both 2025-era and 2026-07-28 MCP protocol revisions over stdio

[smartinellibenedetti]

About this change

Jira Ticket: N/A

Purpose of the Changes

Opts this server into the MCP 2026-07-28 ("modern era") protocol revision over stdio, in addition to the 2025-era protocol it already served. The v2 SDK's modern-era support is opt-in — a hand-wired server.connect(new StdioServerTransport()) (what this server did before this PR) only ever serves the 2025-era protocol, regardless of SDK version.

Switches the bootstrap in src/index.ts to serveStdio(buildServer) from @modelcontextprotocol/server/stdio. This wraps the existing server construction (all setRequestHandler registrations, unchanged) in a buildServer() factory; serveStdio pins one instance from that factory per connection and transparently serves both protocol eras from the same handler code via the SDK's legacy shim — no handler logic changes were needed.

Also adds inspector.config.json (a catalog entry with protocolEra: "modern") and points npm run inspect at it via --config/--server, since MCP Inspector's ad-hoc launch mode (mcp-inspector <command>) has no persisted server entry for a Protocol Era setting to attach to — without this, Inspector has nothing to let you flip to Modern era in its UI.

Builds on sdk-update (the v1→v2 MCP SDK migration branch, PR #83) — this PR targets sdk-update, not main.

Kind of Change

• Bug Fix
• Enhancement/New Feature/Behavior
• Maintenance/Refactor
• Other... (FILL IN)

Development Checklist

• npm run validate passes locally (build + test + integration validations)
• Unit tests added/updated for modified code — no new unit tests added; existing 320 tests pass unchanged (they exercise 2025-era behavior via @modelcontextprotocol/client's standard connect, which now runs through the legacy shim). Modern-era behavior was verified manually (see Testing below) rather than via an automated test, since it requires hand-constructing a raw 2026-07-28 envelope claim that the SDK's client library doesn't yet expose a high-level API for.
• New/changed tools, resources, or prompts documented in CLAUDE.md if applicable — N/A, no tool/resource/prompt surface changed
• New environment variables documented in CLAUDE.md's Environment Variables table — N/A, none added
• Docs download / RUNDECK_DOCS_PATH behavior unaffected, or changes called out below — unaffected

Testing

Testing setup:

npm install
npm run build
npm test
npm run validate

Then, to confirm modern-era negotiation specifically (not covered by the automated suite):

# Hand-built 2026-07-28 opening against the built server, over one connection:
# server/discover -> tools/list -> tools/call, each stamped with the modern
# envelope claim (_meta: protocolVersion/clientInfo/clientCapabilities).
# All three came back resultType: "complete"; server/discover reported
# supportedVersions: ["2026-07-28"] and serverInfo in its _meta.

Also verified via the actual Inspector tool, not just raw JSON-RPC:

npx mcp-inspector --cli --config ./inspector.config.json --server rundeck-mcp --method tools/list --format json

succeeds with protocolEra: "modern" set in the config entry.

Acceptance Criteria:

• npm run build succeeds with no TypeScript errors
• npm test passes (320/320) — confirms 2025-era behavior is unchanged
• npm run validate passes
• A raw 2026-07-28-envelope server/discover request against the built server succeeds and reports supportedVersions: ["2026-07-28"]
• A full modern-era round trip (server/discover -> tools/list -> tools/call) completes with resultType: "complete" at every step
• npm run inspect launches cleanly via the new catalog-config invocation and Inspector negotiates Modern era against this server

[Copilot]

Pull request overview

This PR updates the server’s stdio bootstrap to opt into MCP’s 2026-07-28 (“modern era”) protocol revision while continuing to serve the existing 2025-era protocol via the SDK’s legacy shim. It also updates the MCP Inspector workflow so local inspection can explicitly negotiate modern era.

Changes:

• Switch stdio startup in src/index.ts from a hand-wired transport connection to serveStdio(...) to support both protocol eras.
• Add an integration regression test that pins the client to 2026-07-28 and performs a full round trip.
• Update Inspector usage: add inspector.config.json, bump @modelcontextprotocol/inspector, and change npm run inspect to use the config entry.

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
src/index.ts	Migrates stdio bootstrap to serveStdio and adds logging for opening/negotiation errors.
src/tests/integration/integration-server-tool-gating.test.ts	Adds modern-era pinned integration coverage to catch regressions in stdio wiring.
package.json	Updates Inspector dependency and changes inspect script to use a persisted config/server entry.
inspector.config.json	Adds MCP Inspector catalog entry with protocolEra: "modern" for this server.

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[smartinellibenedetti]

Superseded by #88 — same sdk-update base, but includes the elicitInput→MRTR rework for destructive-action confirmation this PR didn't yet have, plus cacheHints, the resources/templates/list fix, and broader test coverage on both protocol eras.