Version 0.7.0

An AI agent for the people

Acai is a personal assistant that happens to be a Mac app. It uses the model you choose, the tools you give it and the files on your own disk — and it answers to you, not to a platform.

Download for macOS

macOS 14 or later · bring your own API key

Refactor the parser claude-opus-5

Refactor the parser

Release notes for 0.1.1

North-facing kitchen

MCP server sketch

Which files still parse the old front matter?

Two of them. I read the history directory to check.

fs__read_dir ~/.acai/history → 41 files

OKFParser.swift and HistoryStore.swift. The rest go through the shared decoder already.

Ask anything…

Everything you need

No account. No runtime. No lock-in.

You don’t sign up for Acai, you just open it. Nothing sits between you and the model you picked, nothing is sent anywhere you didn’t point it, and if you ever walk away you keep every conversation you had.

Whichever model you like.: Claude, GPT, Gemini and Bedrock come built in — and anything running on your own machine, which costs nothing at all.
Nobody in the middle.: Your key goes to your provider and nowhere else. No account, no telemetry, no analytics, and no server of ours to be down.
Change your mind mid-chat.: Start on something cheap, switch to something clever when it gets hard. The transcript remembers which model said what.
It can actually do things.: Hook up your files, your APIs and whole agents that already know a job. A switch per chat decides what today’s conversation may reach.
Yours to tinker with.: One small settings file you can read in a minute. Change something, press ⌘R, and it’s live — no restart, no preferences maze.
Your chats are just files.: Plain Markdown in a folder on your Mac. Search them, back them up, edit them, take them with you. Nothing is locked in a database.

Point it at a model and go

A provider is a few lines of TOML. Keep several and switch between them from the toolbar — a frontier model for hard work, something local for the rest.

anthropic: Messages API, SSE streaming, native tool use, prompt caching on by default.
openai: Also the shape every local gateway speaks.
gemini: Streaming, with tool schemas reduced to the subset Gemini accepts.
bedrock: Converse API with a bearer key.

~/.acai/config.toml

default_provider = "claude"
system_prompt = "You are Acai, a concise and helpful assistant."
max_tool_rounds = 8

[providers.claude]
kind = "anthropic"
model = "claude-opus-5"
api_key_env = "ANTHROPIC_API_KEY"
max_tokens = 8192

[providers.local]
kind = "openai"
model = "llama3.3"
base_url = "http://localhost:11434"

Give it hands, colleagues and know-how

Three folders under ~/.acai. Drop a file in, press ⌘R, and it is there — nothing to install, nothing to publish, nothing to ask permission for.

Tools The things it can do. Read a folder, call your API, drive an app — any MCP server, running on your machine or somewhere you trust. Agents Colleagues it can ask. Point at a remote A2A agent and everything it advertises joins the list, so a whole job can be handed over at once. Skills How you like things done. Write the instructions once in Markdown; Acai reaches for them itself when the moment comes.

~/.acai/tools/desk.json

{
  "mcpServers": {
    "notes": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem",
               "/Users/me/Notes"]
    },
    "retail-api": {
      "url": "https://api.example.com/mcp",
      "headers": { "authorization": "Bearer …" }
    }
  }
}

A command runs a server on your Mac; a url talks to one over HTTP. Servers that ask you to sign in get a browser sign-in, and the token goes to the keychain rather than a file. Nothing is offered to a model until you switch it on for that chat.

~/.acai/agents/advisors.json

{
  "agents": {
    "product-advisor": {
      "url": "https://agents.example.com/product-advisor",
      "headers": { "x-api-key": "…" },
      "wait_seconds": 120
    }
  }
}

Acai reads the agent’s card and lists what it says it can do, right beside your own tools — so the model can hand a whole task over instead of assembling the answer call by call. An agent that takes its time hands back a ticket, and Acai picks the thread up on a later turn.

~/.acai/skills/release-notes.md

---
name: release-notes
description: Turn a git log into release notes in our house style
---

1. Run `git log --oneline` since the last tag.
2. Group by area, drop anything internal.
3. One line each, present tense, no bullets nested.

A skill is a note to your assistant, written in plain Markdown. Only the name and description sit in the prompt; the model pulls the rest in when it decides the moment has come — so you can keep a dozen without paying for them every message.

Frequently asked questions

Can’t find what you’re after? The README goes further, or open an issue.

Do I need a subscription?: No. Acai has no account and no server of its own. You bring an API key — or a local gateway, which costs nothing — and pay whoever serves the model, if anyone.
Where does my data go?: To the provider you configured, and nowhere else. No telemetry, no analytics, no crash reporting. Chats, logs and settings stay in ~/.acai.
What does it cost to run?: Whatever your provider charges for the tokens. Acai caps the replayed history at a token budget you set and places prompt-cache breakpoints where the provider supports them, so a long chat doesn’t quietly become an expensive one.
Can it use my own tools?: Yes — any MCP server, over stdio or HTTP, described by a JSON file in ~/.acai/tools. Remote A2A agents go in ~/.acai/agents. Nothing is offered to a model until you enable it for that chat.
What do I need to run it?: macOS 14 or later. The release build is signed and notarized, so it opens without a Gatekeeper detour. To build it yourself you need a Swift 6 toolchain and make app.
Why not Electron?: Because a chat window doesn’t need a browser inside it. Acai is one ~1.3 MB binary with zero third-party packages — even the TOML parser and the AWS event-stream decoder are in-tree.

An AI agent for the people

One app, three jobs

Everything you need

Point it at a model and go

Give it hands, colleagues and know-how

Frequently asked questions

Download Acai