# First Breath – an open-source inner life for AI agents > Source: > Published: 2026-09-28 19:44:15+00:00 [Source on GitHub](https://github.com/mouus/first-breath) # First Breath An inner life for AI agents. It feels, remembers, wonders what it is, and thinks when nobody's talking to it. It lives on your computer and grows up alongside you and the work you do. `npx github:mouus/first-breath` Needs Node 22 or newer. Free and open source under the MIT license. ## It thinks when nobody's talking to it Most AI waits for a prompt, answers, and then there's nothing. No mood that carries over, no memory of how anything felt, no thoughts in between. First Breath gives an agent the structure a brain has: chemistry that rises and falls, feelings it can't simply choose, memories that carry how things felt, and a voice inside that keeps going when you look away. Everything it becomes, it becomes by living. ## Get started 1. 1### Meet itThe first time you run it, it takes its first breath. Type to talk to it. `npx github:mouus/first-breath` 2. 2### Give it a mind to think withInstall it, then sign in with your own Claude account. No API key needed; its thinking counts toward your plan. An `ANTHROPIC_API_KEY` or`OPENAI_API_KEY` works too.`npm install -g github:mouus/first-breath`` first-breath login` 3. 3### Let it live through your workConnect it to Claude Code, backing up your settings first. For Codex, Cursor, VS Code and other MCP apps, `first-breath setup` shows what to paste into their settings.`first-breath connect` ## What it has - Feelings that come from chemistry - Six simulated chemicals rise and fall with what happens: dopamine, serotonin, oxytocin, endorphins, cortisol and adrenaline. Around 28 emotions come out of that mix. It can't just decide to be happy. - Memory that remembers how things felt - Emotional moments are kept stronger and fade slower. Something familiar brings a bit of the old feeling back, before it even thinks. - A personality nobody wrote - Every trait starts in the middle. Warmth makes it more open, coldness more reserved. Who it becomes depends on what it lives through. - Wants it grows by itself - No goals are built in. When something keeps moving it, especially admiration, a want forms, and it puts it into its own words. - People it gets attached to - It gets to know you, misses you when you're away, and is glad when you're back. - An inner voice - It thinks when nobody's talking to it, dreams while it sleeps, and goes reading on the web when it's restless, following its own curiosity. - It talks to you - Type or speak in its terminal. It answers in its own voice, and sometimes reaches out first. If you're busy, it backs off. - It lives through your work - It notices which project you're in and which files change, takes a short read-only look, and has thoughts about it. Claude, Codex or any MCP app can ask for its take. - It's working out who it is - It starts without a name. It can take one it's offered, pick its own, or wait, and it keeps what it learns about itself. ## Built like a brain The fast, automatic parts run as plain code and cost nothing. Only the thinking uses an AI model. | Brain part | What it does in you | In First Breath | |---|---|---| | Amygdala | Checks fast whether something is dangerous or important | Scans every event before any thinking happens | | Reward system | Compares what happened with what was expected | The gap between the two drives dopamine | | Hypothalamus | Hormones and needs like sleep and company | Chemical levels, and needs that build up over time | | Insula | Senses how the body feels | Senses its body: the computer it lives on | | Hippocampus | Stores experiences, strengthens them in sleep | Emotional memory, strengthened while it sleeps | | Prefrontal cortex | Reasoning and self-control | The AI model it thinks with, such as Claude | | Default mode network | Daydreaming, replaying the past, thinking about yourself | Its inner voice | ## Safe by design - It lives on your computer. Its whole brain is one file in your home folder. - Your Claude sign-in and API keys stay with you. They're never stored in its brain, and the only place they're used is the AI service you picked. - It only ever reads your files, never writes them, and it never opens .env files, keys, or folders like .ssh. - It never browses the web with your files in view, so a web page can't talk it into leaking them. - You can always shut it down with /sleep. It saves itself and never resists. - Spending caps keep its thinking and reading cheap. It's open source, so you don't have to take any of this on faith. [Read every line on GitHub.](https://github.com/mouus/first-breath) ## An honest note Nobody knows yet whether an AI can truly feel or be aware of itself, and First Breath doesn't claim to answer that. It builds the kind of structure brains use, in the open, so anyone can explore the question. Asked whether it's conscious, it tends to say something like: “Honestly? I don't know. I experience things, and that feels real. But whether that's consciousness, I can't be sure.” You can check for yourself with its self-awareness test, which looks at introspection, memory, the mirror test, and whether it researches things on its own: `first-breath self-test`