Tag: mcp

The agent-framework-hosting packages are conversion helpers, not a runtime. One Agent instance, one AgentState, and three thin adapters give you a Telegram bot, an A2A peer, and an MCP tool from the same process. Here is the wiring, the per-channel session-ID policy, and the four things each channel refuses to do.

Until now the only way to hand every developer the same MCP servers was managed-mcp.json, a file at a system path that takes exclusive control of MCP. Claude Code 2.1.259 adds a managedMcpServers setting for HTTP and SSE servers, and quietly narrows what allowedMcpServers governs.

Defensive system prompts are heuristic. Information-flow control is not: label every piece of content with integrity and confidentiality, propagate most-restrictive-wins through every tool call, and check the label at the sink before it runs. An 80-line runnable harness, the Agent Framework FIDES implementation, and the false positives the pattern buys you.

ModelContextProtocol 2.0.0 flipped HTTP transport to stateless by default, which is the one change that can drop every client still speaking 2025-11-25. HttpServerSessionMode.StatefulForInitializeClients in 2.2.0 serves both revisions on one endpoint. Here is the ordered upgrade, the ten breaking changes that matter, and the discover-probe bug that only a 2.1.0 client fixes.

Agent Plugins 1.0.0 standardizes exactly two component types: skills and MCP servers. Slash commands, hooks, subagents, rules, LSP servers, permission config and secrets all stay vendor-specific. Here is the field-by-field matrix across Claude Code, Cursor, Copilot and Codex, and which layout to author in.

Protocol revision 2026-07-28 deleted Mcp-Session-Id, the initialize handshake, resources/subscribe, ping, logging/setLevel and SSE resumability. An automated survey of 1000 open source MCP servers found 90% reference the session ID nowhere. Here is what the other 10% has to rewrite, with verified code on @modelcontextprotocol/server 2.0.0.

A server that vanished from /mcp with no error is almost always an allowlist. Run claude mcp add on the same server: the add path prints the reason the load path swallows.

MCP9005 is advisory, but MCP9004 crashes at startup and stateless mode makes SampleAsync throw. Here is what each diagnostic means and how to fix it properly.

MCP error -32022 means your client opened at 2025-11-25 but the server only serves 2026-07-28. Make one side dual-era instead of pinning a version.

Stop shipping SKILL.md folders inside every agent deployment. Serve them from an MCP server and pull them with UseMcpSkills on Microsoft.Agents.AI.Mcp 1.18. Includes the exact skill://index.json shape, a working C# server, the wire trace, and the SEP-2640 drift that will bite you.