AI tool comparison
Apfel vs CatDoes v4
Which one should you ship with? Here is the side-by-side panel verdict, pricing read, reviewer split, and community vote comparison.
Developer Tools
Apfel
Tap the free AI already built into your Mac
75%
Panel ship
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Community
Free
Entry
Apfel is a Swift 6.3 command-line tool that cracks open the on-device language model Apple ships with every Apple Silicon Mac running macOS 26 (Tahoe). Instead of requiring a Claude, OpenAI, or Gemini subscription, Apfel routes through Apple's FoundationModels framework and gives you three interfaces from a single brew install: a pipe-friendly CLI, an interactive chat with context management, and an OpenAI-compatible local HTTP server built on Hummingbird. Under the hood, every token is generated on your Neural Engine and GPU — nothing leaves your machine. The model is roughly 3B parameters with a 4,096-token context window, fast enough for scripting, summarisation, and quick Q&A without latency you'd notice. Pipe-friendly stdin/stdout, JSON output mode, and proper exit codes make it trivially composable with jq, xargs, and shell scripts. The OpenAI-compatible server mode is the killer feature for developers: point any tool that speaks the OpenAI API at localhost and it just works — locally, for free, with zero cold-start. The project is MIT-licensed, started by a solo developer on March 24, 2026, and hit 513 HN points within days of the Show HN post.
Developer Tools
CatDoes v4
An AI agent with its own cloud computer builds your mobile apps
75%
Panel ship
—
Community
Free
Entry
CatDoes v4 ships with Compose — an autonomous AI agent that runs on its own cloud computer to build mobile apps, websites, and internal tools from plain text descriptions. You describe what you want, Compose plans the work, writes code, runs tests, fixes its own errors, and deploys — even after you close the browser tab. Every project comes pre-wired with a full backend stack: database, authentication, storage, edge functions, and real-time events. The v4 release focuses on higher reliability and GitHub integration for developers who want to export and own their codebase. Free plans start at 25 credits; paid plans begin at $20/month with more projects and higher cloud limits. What distinguishes CatDoes from the crowded AI app builder space is the "own computer" framing. The agent doesn't just generate code for you to paste — it has an execution environment where it can actually run and debug the app, catching errors before you see them. Whether that closed-loop debugging holds up in practice for complex apps is the open question.
Reviewer scorecard
“The OpenAI-compatible server is a genuine unlock — I swapped my local dev config from Ollama to Apfel in two minutes and everything just worked. For Apple Silicon owners who want zero-latency local AI without model downloads, this is the move.”
“The closed-loop debugging is the real differentiator. Most AI code generators dump code on you and walk away — Compose actually runs the result and iterates. At $20/month with code export and GitHub sync, it's a serious prototyping accelerator even for experienced devs who just want to skip the boilerplate.”
“A 3B-parameter model with a 4K context window is impressive for on-device, but it's nowhere near Claude or GPT-5.5 quality. If your task needs real reasoning or long context, you're back to paying for API credits anyway. This is a neat party trick, not a replacement.”
“Every AI app builder claims autonomous error-fixing, and in practice they all hit the same wall: anything beyond CRUD starts failing in unpredictable ways. CatDoes is also a relatively unknown indie — if they fold or pivot, you're left with a codebase that was built in their proprietary stack. Export and own is a good safety valve, but validate it before depending on it.”
“Apfel is the first glimpse of a world where capable on-device AI comes pre-installed, not downloaded. As Apple's model improves with each macOS release, tools like Apfel will inherit the upgrade for free. The distribution moat Apple is quietly building here is enormous.”
“This is the trajectory: agents that don't just write code but execute, test, and observe it running. When the agent can monitor its own output in production and self-correct, we've crossed into genuinely autonomous software development. CatDoes is an early bet on that future at an indie scale.”
“I used it to batch-summarise 40 draft posts overnight with a simple shell loop — no API bill, no rate limits, no internet required. For content workflows that need a cheap first pass, it's already practical.”
“As a designer who occasionally needs a working prototype but doesn't want to learn Swift or React Native, this is a gift. Being able to describe an app in natural language and get something testable on a real device within an hour is exactly the kind of tool that removes the 'I need a developer' blocker from creative projects.”
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