Tag: ai-agents

A coding agent refactors a component, renames a data-testid, and your Playwright suite goes red. Here is a three-layer setup, verified on Playwright 1.63.0 and Claude Code 2.1.197: locators that survive, a PreToolUse hook that blocks the rename, and a CI guard that lets the Playwright healer agent fix locators but never rewrite an assertion.

Every agent request pays for its system prompt, the provider's hidden tool-use preamble, and every tool schema before the user says anything. How to measure that fixed cost with differential count_tokens calls on the Anthropic API, the input_tokens endpoint on OpenAI, an MCP listTools probe, and /context in Claude Code, anchored to claude-opus-5-5, claude-sonnet-5, and @modelcontextprotocol/client 2.1.0.

The AG-UI protocol now has a standalone .NET SDK: AGUI.Server 1.0.0 streams any IChatClient as AG-UI events over SSE, and AGUIChatClient consumes an AG-UI endpoint as an IChatClient, down to .NET Framework 4.7.2. Agent Framework users get renamed APIs.

Dev containers, Docker Sandboxes microVMs, Lima VMs, and hosted cloud sandboxes all move Claude Code, Codex, or Copilot CLI off your host. What each one actually isolates, the exact commands to make it throwaway, and the two things none of them protect: your writable workspace and your git hooks.

Scoping a token does not stop a prompt-injected agent from leaking it. Moving the token out of the agent's process does. Three working setups: a 50-line gateway any agent can call, Claude Code 2.1.199+ sandbox masking with injectHosts, and Claude Managed Agents vaults, plus the measured leak that host-level injection still allows.

Move a repo, its Cursor cloud agents, automations, Bugbot, and CI from GitHub to Cursor Origin without a flag day: mirror first, rewire agents and CI while GitHub is still the source of truth, then cut over with Detach from GitHub or the reversible inbound_to_outbound mirror transition. Covers what breaks, the Origin CLI and API calls, a ref-parity check, and the rollback path.

Claude Code 2.1.277 reads AGENTS.md natively, so Cursor, Claude Code, and most Copilot surfaces can now share one instructions file. Here is the checklist for merging three drifted rule files into AGENTS.md, which bridge files to delete, the one Copilot file you still have to generate, and a CI check that keeps them from drifting again.

A side chat branches off what the agent already knows; a subagent goes and finds out something new. Claude Code's /btw has no tools at all, Cursor's /btw opens a full agent, and a plain subagent sees none of your conversation. A decision guide for Claude Code 2.1.278 and Cursor 3.11+.

Move a local stdio MCP server to a remote Streamable HTTP server behind OAuth on MCP spec 2026-07-28 and TypeScript SDK 2.0.0. Dynamic Client Registration is now deprecated, so use Client ID Metadata Documents first and keep DCR only as a fallback. Covers the steps, a measured CIMD/DCR test matrix, and the misleading error you get when the two sides disagree.

Microsoft Agent Framework .NET 1.22.0 adds AIAgent.AsIChatClient(), closing the round trip with IChatClient.AsAIAgent(). Your agent, with its instructions and tools intact, now plugs into any API that takes an IChatClient.