Every roundup for April 11-12, 2026 lists weights. The provider matrix changed underneath and three lines of Swift are doing the work of 206.

The 48-hour window saw Google relax Gemma 3's commercial license on April 11 (removing the prior user-count clause), continued uptake of Meta's Llama 4 and Llama 4 Maverick checkpoints, fresh Qwen 3 variants from Alibaba, Mistral's Codestral 2 under Apache 2.0, Ai2's OLMo 2 32B, and a GLM-5.1 community quantization wave on Hugging Face. On the paper side, DeepSeek V3's training-recipe supplement and The AI Scientist-v2 (workshop-level agentic tree search for scientific discovery) were the most-shared arXiv drops. On the tooling side, MCP (Model Context Protocol) moved under Linux Foundation governance, which matters more for consumer-grade desktop agents than any of the weight releases.

Fazm shipped v2.2.0 on April 11 with a single new setting that accepts an HTTPS URL and, when set, routes all agent traffic through that endpoint by exporting ANTHROPIC_BASE_URL to the ACP bridge child process. Twenty-four hours later (April 12, afternoon Pacific), Fazm deleted Vertex AI entirely: VertexTokenManager.swift (206 lines) was removed in commit f095d7b2, Vertex fallback logic was stripped from ChatProvider.swift in commit 36c089d2 (51 of 53 lines gone), and the bridge-mode enum lost its Vertex variant in 02ccd919. The provider matrix collapsed from three rails (Claude Pro/Max + Vertex + bundled Anthropic) to two (personal Claude + bundled Anthropic), plus the user-configurable ANTHROPIC_BASE_URL override that replaces everything else. For any reader who wants to point a native Mac agent at Codestral 2 via a local claude-compatible proxy, or at Llama 4 Maverick through LiteLLM, this is the weekend the path became two UI clicks long.

Three locations. The runtime injection lives at Desktop/Sources/Chat/ACPBridge.swift lines 379-382: `if let customEndpoint = defaults.string(forKey: "customApiEndpoint"), !customEndpoint.isEmpty { env["ANTHROPIC_BASE_URL"] = customEndpoint }`. The setting storage lives at Desktop/Sources/MainWindow/Pages/SettingsPage.swift line 840 (`@AppStorage("customApiEndpoint") private var customApiEndpoint: String = ""`). The UI toggle and TextField render at the same file lines 906-952. That is the entire contract. No DSL, no YAML, no per-provider adapter.

Commit f095d7b2 (2026-04-12 16:53:00-07:00) deleted 206 lines of service-account OAuth plumbing in VertexTokenManager.swift: Google service-account JSON parsing, JWT assertion signing with CryptoKit, token exchange against https://oauth2.googleapis.com/token, token caching with expiry, and refresh-on-401 logic. Commit 36c089d2 (one minute earlier) stripped 51 of 53 lines of Vertex fallback from ChatProvider. Commit 02ccd919 (a minute before that) removed the Vertex branch from ACPBridge's bridge-mode enum, which used to choose between `.anthropic`, `.vertex`, and `.claudePro`. The afternoon of April 12 is twelve commits long in the fazm repo and removes every trace of Vertex.

Any runtime that exposes Anthropic's Messages API shape becomes a drop-in target. The known-working adapters as of April 12 are (1) LiteLLM's `/v1/messages` bridge, which fronts OpenAI, Gemini, Ollama, vLLM, and local servers under a single Claude-compatible URL, (2) claude_code_proxy and similar open-source translation layers, (3) Cloudflare AI Gateway with transformation rules, and (4) any corporate proxy that speaks the Messages API (e.g. GitHub Copilot Enterprise's internal bridge, several internal platform teams' homebrew gateways). Flip on the Custom API Endpoint toggle in Settings, paste the URL, and restart the bridge (the Settings toggle calls `chatProvider?.restartBridgeForEndpointChange()` on save). Fazm's tool surface (accessibility tree, not screenshots) is routed through the new endpoint unchanged.

No. Fazm's desktop control path is mcp-server-macos-use, a native Swift/ObjC binary bundled in the app that calls AXUIElementCreateApplication and AXUIElementCopyAttributeValue directly. The tool surface any model sees is a structured accessibility tree (roles, labels, bounds) formatted as text, not a pixel buffer. Swapping the model via ANTHROPIC_BASE_URL does not change the tool surface. You are not retraining against a new screenshot distribution every time a new weight drops.

v2.2.0 was released on 2026-04-11 (commit 1a24eaa7, 'Release changelog for v2.2.0', 2026-04-11 01:53:32 UTC). The release notes in CHANGELOG.json lines 37-49 call out: custom API endpoint setting for proxies and corporate gateways (the headline feature), global shortcut Command-Shift-N to open a new pop-out chat window, paywall copy that highlights full desktop control, a 600ms debounce on the typing indicator to stop flicker during retries, founder-chat crash-loop fix on repeated rate-limit failures, and fixes for pop-out windows not restoring after update and suggested replies leaking across chat sessions. v2.2.1 followed on April 12 with a single targeted fix for duplicate AI bubbles in the pop-out window during follow-up questions.

ACP (@agentclientprotocol/claude-agent-acp) is the wire protocol the Fazm Mac app uses to talk to its acp-bridge child process, which in turn talks to Claude (or any endpoint ANTHROPIC_BASE_URL points at). On April 11-12 Fazm was running ACP 0.25.0 (per v2.1.2 notes on April 7); the SDK got bumped later in the month. The important property for this article is that ACP is the reason the endpoint switch is cheap: all model traffic goes through one child process, and that child process reads ANTHROPIC_BASE_URL from its environment at spawn. Restart the bridge, the new endpoint is active. No app rebuild, no re-auth flow.

Yes. Four files, no marketing. /Users/matthewdi/fazm/Desktop/Sources/Chat/ACPBridge.swift lines 379-382 (the env injection). /Users/matthewdi/fazm/Desktop/Sources/MainWindow/Pages/SettingsPage.swift lines 840 and 906-952 (the @AppStorage key and the UI). /Users/matthewdi/fazm/CHANGELOG.json lines 37-49 (v2.2.0 release notes with the April 11 date). git log --all --since='2026-04-11' --until='2026-04-12 23:59' in the fazm repo, which shows the v2.2.0 release commit, the twelve Vertex-removal commits clustered at 16:52-16:53 PT on April 12, and the v2.2.1 changelog commit at 20:10 UTC on April 12.

Because the custom-endpoint override covers that use case in fewer lines. Anyone who was hitting Claude via Google Vertex AI's Anthropic models can set ANTHROPIC_BASE_URL to their Vertex proxy (or to an internal LiteLLM instance that speaks to Vertex) and keep working. The cost of maintaining a first-class Vertex rail was two files and an auth path that was unique to Google (service-account JWTs, per-project quotas, region pinning). The cost of maintaining ANTHROPIC_BASE_URL is three lines in ACPBridge.swift and a UserDefaults key. The simplification also makes the consumer story legible: there are two built-in routes (your Claude Pro/Max subscription or Fazm's bundled key) and one override for everything else.

For desktop-automation tool calls specifically, Codestral 2 (Apache 2.0) is strong because it was trained heavily on tool-use traces and runs well on consumer GPUs via vLLM or llama.cpp-server; a local server wrapped by LiteLLM's Claude-compatible endpoint gives you a zero-cost route. Llama 4 Maverick is the better fit if you want reasoning quality close to Claude Sonnet. Qwen 3 has the best multilingual behavior if your automations cross into non-English UI text. GLM-5.1 quantizations are the smallest footprint. Regardless of which you pick, the Fazm-side change is the same: paste the endpoint URL into Settings > Custom API Endpoint, restart the bridge, watch /tmp/fazm-dev.log for the 'anthropic_base_url set' entry in the bridge spawn env.

ACPBridge surfaces the connection error through the normal error path the UI uses for Anthropic outages (the same path that handles rate limits and credit exhaustion since v2.1.2). There is no silent fallback to the built-in key; the user sees the error and can either toggle Custom API Endpoint off, which drops ANTHROPIC_BASE_URL from the bridge env on its next spawn, or they can fix the endpoint and hit Send again. The April 12 Vertex removal is what makes this behavior deterministic: there is no third rail to half-silently fall through.