Johannes Wachter ยท EverythingEverything in one feed: the writing and the shorts, newest first.https://johanneswachter.dev/enSymfony Language Tools stopped taking patcheshttps://johanneswachter.dev/shorts/symfony-language-tools-stopped-taking-patches/https://johanneswachter.dev/shorts/symfony-language-tools-stopped-taking-patches/Symfony's new Language Tools repository closed its pull request tab. Contributors now start with an issue instead. Maintainers turn selected issues into code, usually with a coding agent doing much of the implementation work. Fabien's reasoning is what stuck with me.Fri, 04 Sep 2026 00:00:00 GMTsymfonyopen-sourceaiThe hardest code to delete is your ownhttps://johanneswachter.dev/blog/the-hardest-code-to-delete/https://johanneswachter.dev/blog/the-hardest-code-to-delete/My first Symfony AI release as a core team member deletes the MCP server from Mate. PR #2380 ships in 0.13, and what it actually cost to ship the answer.Mon, 31 Aug 2026 00:00:00 GMTaimcpphpsymfonymateRoots shipped inside its own deprecation windowhttps://johanneswachter.dev/shorts/roots-shipped-inside-its-own-deprecation-window/https://johanneswachter.dev/shorts/roots-shipped-inside-its-own-deprecation-window/MCP's 2026-07-28 specification deprecated Roots, Sampling and Logging, with at least twelve months before they become eligible for removal. On August 14th, my Roots support PR merged into the official PHP SDK. None of this was hidden.Sun, 30 Aug 2026 00:00:00 GMTmcpphpopen-sourceMate's MCP server is gone, and the numbers say that's finehttps://johanneswachter.dev/shorts/mates-mcp-server-is-gone/https://johanneswachter.dev/shorts/mates-mcp-server-is-gone/symfony/ai 0.13 shipped today, my first release as a core team member. The headline change for Mate is PR #2380: Mate drops its MCP server entirely and becomes a plain CLI with a discovery layer on top.Sat, 29 Aug 2026 00:00:00 GMTsymfonyaimateBeing neutral is easier without a price taghttps://johanneswachter.dev/shorts/being-neutral-is-easier-without-a-price-tag/https://johanneswachter.dev/shorts/being-neutral-is-easier-without-a-price-tag/Nvidia has reportedly agreed to buy Hugging Face for 12.9 billion dollars, according to The Information. Other reports put the talks above 13 billion, with no deal signed yet. Neither company has confirmed it. What catches me isn't the price, it's the buyer.Fri, 28 Aug 2026 00:00:00 GMTaiopen-sourceOpen weights don't tell you what's insidehttps://johanneswachter.dev/shorts/the-passport-isnt-the-point/https://johanneswachter.dev/shorts/the-passport-isnt-the-point/A growing argument on my feed: switch to Chinese AI models, because they ship open weights and open beats closed. Open weights are a real property. You can download the file, inspect it, run it yourself. What they don't guarantee is what's actually baked into the answers.Thu, 27 Aug 2026 00:00:00 GMTaiopen-sourceThe Mate Lab: does an agent actually use a dev tool?https://johanneswachter.dev/blog/mate-lab/https://johanneswachter.dev/blog/mate-lab/I measured whether Symfony Mate actually gets used by a coding agent, not just whether it's available. The result behind the Kill the MCP bet.Tue, 25 Aug 2026 00:00:00 GMTaimcpsymfonymateMore instructions were not making Claude betterhttps://johanneswachter.dev/shorts/context-engineering-for-claude-5/https://johanneswachter.dev/shorts/context-engineering-for-claude-5/Anthropic cut more than 80% of Claude Code's system prompt for the Claude 5 generation models, with no drop in coding evals. What interests me isn't the number.Tue, 25 Aug 2026 00:00:00 GMTaiagentic-aicontext-engineeringNobody has the answers yet, and that's the openinghttps://johanneswachter.dev/shorts/nobody-has-the-answers-yet/https://johanneswachter.dev/shorts/nobody-has-the-answers-yet/A post going around traces this back to something Kent Beck keeps repeating on his podcast "Still Burning": nobody has the answers.Tue, 25 Aug 2026 00:00:00 GMTaiagentic-aiThe dangerous instruction was never in one tool callhttps://johanneswachter.dev/shorts/no-single-message-says-the-dangerous-part/https://johanneswachter.dev/shorts/no-single-message-says-the-dangerous-part/A disclosed technique called GhostSplice shows that an MCP server does not need to put anything obviously dangerous in a single message.Sun, 23 Aug 2026 00:00:00 GMTaimcpsecurityThe repository was the easy parthttps://johanneswachter.dev/shorts/the-repository-was-the-easy-part/https://johanneswachter.dev/shorts/the-repository-was-the-easy-part/GitHub spent almost eight hours on Monday returning errors across git operations, pull requests, Actions, Pages and Copilot. By the afternoon an Ask HN thread about alternatives to GitHub was on the front page with a few hundred comments.Thu, 20 Aug 2026 00:00:00 GMTopen-sourcedeveloper-toolingaiI can manufacture anything except a sense of ownershiphttps://johanneswachter.dev/shorts/manufacture-everything-except-ownership/https://johanneswachter.dev/shorts/manufacture-everything-except-ownership/Helge Sverre had Claude and Suno write a song about a coding agent slowly taking over a team's daily standup. One line in the second verse says more than most articles on the subject.Tue, 18 Aug 2026 00:00:00 GMTaiagentic-aicultureA Rector extension for Symfony Matehttps://johanneswachter.dev/shorts/rector-extension-for-symfony-mate/https://johanneswachter.dev/shorts/rector-extension-for-symfony-mate/The new Rector extension for Symfony Mate splits one tool into two: rector-preview runs dry-run enforced and cannot write, rector-apply is a separate tool that announces itself as a write operation. Inspecting code is never the thing that changes it. Contributed by mdjdev, not by me.Tue, 18 Aug 2026 00:00:00 GMTmatephpaiMy first merge in symfony/aihttps://johanneswachter.dev/shorts/first-merge-in-symfony-ai/https://johanneswachter.dev/shorts/first-merge-in-symfony-ai/For the first time, I merged a pull request in symfony/ai myself. It was a small fix and not mine, PR #2404, the kind of change that takes a minute to read and no time at all to agree with.Mon, 17 Aug 2026 00:00:00 GMTsymfonyaicareerThe Symfony language server, and who wrote ithttps://johanneswachter.dev/shorts/the-symfony-lsp-and-who-wrote-it/https://johanneswachter.dev/shorts/the-symfony-lsp-and-who-wrote-it/Symfony's new official LSP server ships with a disclosure most projects still keep private: most of the code was written and reviewed by AI models.Mon, 17 Aug 2026 00:00:00 GMTsymfonyaiopen-sourceJoining the Symfony AI Core Teamhttps://johanneswachter.dev/blog/symfony-ai-core-team/https://johanneswachter.dev/blog/symfony-ai-core-team/Chris Hertel asked me to join the new Symfony AI Core Team alongside Fabien Potencier and Oskar Stark. What that actually means to me.Thu, 13 Aug 2026 00:00:00 GMTaisymfonycareerKill the MCPhttps://johanneswachter.dev/blog/kill-the-mcp/https://johanneswachter.dev/blog/kill-the-mcp/I deleted the MCP server from a Mate prototype and kept the tools. What that cost, what it bought, and why the reflex is the thing worth killing.Tue, 04 Aug 2026 00:00:00 GMTaimcpphpsymfonyVibe coding is no-code without a custodianhttps://johanneswachter.dev/blog/vibe-coding-without-a-custodian/https://johanneswachter.dev/blog/vibe-coding-without-a-custodian/Vibe coding can produce maintainable software. The harder question is who owns its dependencies, decisions and failures after launch.Tue, 28 Jul 2026 00:00:00 GMTaivibe-codingownershipmaintenanceThe wrong debate: what PHP taught me about agentic softwarehttps://johanneswachter.dev/blog/the-wrong-debate/https://johanneswachter.dev/blog/the-wrong-debate/MCP or CLI is the wrong fight. What PHP with Composer, PSR and Symfony already learned about building things together, one layer down.Wed, 22 Jul 2026 00:00:00 GMTaimcpphpsymfonyThe last mile: distributing Agent Skills to real agentshttps://johanneswachter.dev/blog/the-last-mile/https://johanneswachter.dev/blog/the-last-mile/The polyfill that bridges where the Agent Skills standard is heading and what agents can read today, and why distribution, not the protocol, was the real problem.Thu, 09 Jul 2026 00:00:00 GMTaiskillssymfonymatemcpSkills over MCP: shipping Symfony know-how with Matehttps://johanneswachter.dev/blog/skills-over-mcp/https://johanneswachter.dev/blog/skills-over-mcp/What an Agent Skill actually is, how you serve one over MCP, and lessons from building a reference implementation against a spec that kept moving.Thu, 02 Jul 2026 00:00:00 GMTaimcpskillssymfonymateWhat happens to innovation when implementation becomes almost free?https://johanneswachter.dev/blog/when-implementation-becomes-free/https://johanneswachter.dev/blog/when-implementation-becomes-free/When code, design and content all get cheaper, maybe implementation was never the bottleneck. A note from the classroom on friction, the statistical mean, and where excellence shows up.Thu, 25 Jun 2026 00:00:00 GMTaiinnovationteachingGiving AI assistants eyeshttps://johanneswachter.dev/blog/giving-ai-assistants-eyes/https://johanneswachter.dev/blog/giving-ai-assistants-eyes/Highlights from the Symfony Mate Q&A: the dev-only MCP server that lets AI assistants look inside your running app, and why better context beats more context.Thu, 18 Jun 2026 00:00:00 GMTaisymfonymcpmateWhy six people are enough and what coding agents have to do with ithttps://johanneswachter.dev/blog/why-six-people-are-enough/https://johanneswachter.dev/blog/why-six-people-are-enough/Six developers run Sulu, its enterprise projects and its cloud services. That only works because of ownership and context, and those are exactly what coding agents need too.Tue, 19 May 2026 00:00:00 GMTaiteamsownershipsulu