Claude Anthropic news, April 2026, read from the one ship the roundups missed

The loud headlines were Claude Opus 4.7 as the general-availability flagship on April 22, 2026, a new product surface called Claude Design for in-line charts and one-pagers, Claude Cowork going generally available on macOS and Windows as a persistent agent thread, the Mythos Preview on April 7 that fed into Project Glasswing for computer-security work, and a brief test where Claude Code was pulled from the $20 Pro plan for roughly 2 percent of new signups before being restored. The piece not covered by roundups is a downstream one: Fazm, a consumer Mac agent that talks to Claude over the Agent Client Protocol, shipped 2.4.0 on April 20 with a user-facing MCP server config whose JSON shape mirrors Claude Code's mcpServers exactly. For anyone who already maintains a Claude Code MCP config, that meant copy, paste, done.

Because MCP server configs are still mostly client-specific. Claude Desktop, Claude Code, Cursor, and every other Anthropic-speaking client pick their own JSON shape, their own storage path, and their own set of built-in servers. If you maintain a non-trivial MCP setup, you maintain N copies, one per client. Fazm 2.4.0 picks Claude Code's shape on purpose. The comment at the top of MCPServerManager.swift reads: Format mirrors Claude Code's mcpServers: { name: { command, args, env, enabled } }. The matching loader in acp-bridge/src/index.ts (lines 1102 to 1137) parses that shape and pushes each entry onto the live server list for the next session. One JSON file now covers two clients.

At ~/.fazm/mcp-servers.json. The path is computed inside MCPServerManager.swift at line 42 as FileManager.default.homeDirectoryForCurrentUser.appendingPathComponent(.fazm).appendingPathComponent(mcp-servers.json). The directory is created on first save with createDirectory(withIntermediateDirectories: true), so you do not need to mkdir it yourself. If the file does not exist, Fazm loads zero user servers and falls back to the built-in set. The Settings UI in SettingsPage.swift at line 1841 surfaces this path verbatim next to an Open button that reveals the file in Finder.

A top-level object whose keys are the server names and whose values have four fields: command (string, required), args (string array, optional, defaults to empty), env (map of string to string, optional, defaults to empty), and enabled (boolean, optional, defaults to true). The RawServerConfig struct in MCPServerManager.swift defines it explicitly. The acp-bridge loader in index.ts validates it, skips entries with enabled=false, and logs 'User MCP server skipped: missing command' and returns early if command is absent. Enabled is omitted from the on-disk JSON when it is true, so enabled:true is the default and only the opt-out case writes an extra field.

The built-in set is appended to, not replaced. buildMcpServers() in acp-bridge/src/index.ts starts by pushing fazm_tools (stdio, the bridge's own tool server that executes SQL against the user's local Fazm database and completes tasks), then appends Playwright MCP (browser automation, launched with an init-page that injects a 'controlled by Fazm' overlay), a native macOS accessibility automation server called macos-use, a native WhatsApp Catalyst automation server called whatsapp, and a Python Google Workspace MCP server. User entries from ~/.fazm/mcp-servers.json are appended after that list. The Settings UI groups them with a 'Built-in' header for the first five and a 'Custom' header for user servers.

It runs. The command, args, and env fields are forwarded to the ACP bridge unchanged. The bridge spawns it as a stdio child process exactly the way Claude Code would. There is no translation step, no shim, no Fazm-specific subprocess wrapper. A server that reads its own credentials from an env var will see that env var because Fazm passes it through. A server that speaks the stdio MCP transport will do the same three-message handshake it does in Claude Code. The only constraint is that Fazm's bridge supports stdio and HTTP transports, which matches what Claude Code supports, so if your config runs in Claude Code it will run in Fazm.

At the next conversation. The hint text under the file path in Settings reads 'Uses the same format as Claude Code. Changes take effect on next conversation.' The bridge builds the server list each time a new session is requested, so quitting the current chat and starting a new one reloads the file. Restarting the app is not required. There is no file watcher, which is intentional: the reload boundary is the session, not the file-system event, so a half-saved JSON file never takes down the active conversation.

Yes. Set enabled:false on the entry. The acp-bridge loader at index.ts line 1115 reads 'if (cfg.enabled === false) continue;' before it does any other validation, so disabled servers are skipped with zero logging and zero side effects. The Settings UI exposes a toggle per custom server that calls MCPServerManager.toggleServer(named:), which flips the field and re-serializes the JSON. That is the same pattern Claude Code uses for its disabled flag, so a disabled-in-Claude-Code server stays disabled when you paste the same JSON into Fazm.

Through a side-channel. After the ACP bridge finishes negotiating a session it emits a 'mcp_servers' event with the parsed list (name, command, builtin flag) up to the Swift parent. ACPBridge.swift at line 1216 decodes that event into MCPServerManager.ActiveServer instances and pushes them via updateActiveServers() onto the @Published array that the Settings page observes. The 'Built-in' section of the Settings UI is the filtered slice where builtin=true, and it reflects what the bridge actually loaded, not what the Swift-side config thinks should load. This distinction matters when a user server silently fails validation: it is absent from the active list and the Settings page shows it dimmed in the Custom section.

Because the April 2026 Anthropic release cycle pushed enough users onto the Agent Client Protocol that a shared MCP story stopped being optional. ACP rolled from v0.25.0 on April 7 to v0.29.2 on April 20. In the same window, MCP-aware servers kept multiplying: WhatsApp, Google Workspace, a dozen community entries. Asking users to maintain a Fazm-specific JSON shape on top of a Claude Code one would have been a tax for no reason. The path of least friction was to pick the shape that already existed and be a compatible client. Version 2.4.0 shipped the loader, the Settings UI, and the open-in-Finder shortcut on April 20, 2026.

Purely a Fazm decision, which is the point. MCP is a protocol, not a config-file spec, so Anthropic does not mandate a JSON shape. Each client can invent its own. Fazm chose to match the Claude Code shape because it is the one with the largest install base of MCP users, and because the team wants the jump between Claude Code on a developer's machine and Fazm on the same developer's (or their spouse's, or their parent's) machine to be as close to a copy-paste as possible. If Anthropic ever publishes a canonical MCP config format, the loader is 35 lines. It will be cheap to migrate.