Tag: ai-agents

A write tool that asks before it writes needs three things the MCP SDK does not give you: an approval bound to the exact diff, a precondition on the file it previewed, and an integrity-protected requestState. Verified end to end on @modelcontextprotocol/server 2.0.0 against protocol revision 2026-07-28, including the argument-swap that gets past a naive confirm.

Mapping 200 internal REST endpoints to 200 MCP tools puts 200 KB of JSON schema in front of every request. The 2026-07-28 spec also made the usual escape hatch illegal: tools/list MUST NOT vary per-connection, so per-session dynamic registration is gone. Here are the three levers that still work, with measured wire sizes and verified code on @modelcontextprotocol/server 2.0.0.

Tightening a team's default permission mode to Manual is a one-line settings change interactively and a silent outage in CI, because headless runs turn every ask into a deny and still report success. Measured on Claude Code 2.1.224, including the trust gate that drops your allowlist but keeps your mode.

The 1M-token context window is now the default on Claude Opus 5, Opus 4.8/4.7/4.6, Sonnet 5, and Sonnet 4.6, with no beta header and no long-context premium. Here is when deleting the vector store actually pays off, the 10x cache-read rule that decides it, the ~30% tokenizer inflation that breaks your sizing estimate, and the seven-step migration with a verification line on each one.

Claude Code 2.1.224 adds claude self-hosted-runner, a public beta that executes cloud sessions on machines you provision. Here is the setup, the one-user runner rule, and what still leaves your network.

The GitHub, Postgres, and Slack MCP servers from modelcontextprotocol/servers were archived in 2025 and their npm packages are deprecated. They pin SDK 1.0.1, which cannot negotiate past protocol 2024-11-05. Here is the audit script, the current replacement for each, and the two pointers in the archive README that are themselves stale.

Cross-session messaging landed on August 7, 2026. ListAgents and SendMessage move plain text between your sessions, and crossSessionInbound decides what actually arrives.

Cursor did not delete rules. It split them. This checklist sorts a .cursorrules file and a folder of .mdc rules into the four things they should be in Cursor 3.11: an AGENTS.md, a small set of surviving rules, skills, and subagents, then bundles the result as a plugin.

GitHub's August 6, 2026 changelog adds allowedMcpServers and deniedMcpServers to copilot/managed-settings.json. URL and argv matchers, deny-wins precedence, and a fail-closed default the older name-based registry never had.

A step-by-step checklist for retiring a hand-rolled while-loop agent and running the same job on @cursor/sdk 1.0.26. The tool bodies survive, the loop does not, and three things you probably rely on have no equivalent: a system prompt string, a tool allowlist, and per-turn control.