A coding agent in one Rust binary. The model works inside a persistent Python kernel, where subagents are function calls and plans are programs.
curl -fsSL https://raw.githubusercontent.com/jackmaxwil/yi/main/scripts/install.sh | bash
yi --versionIt checks the release's sha256 and the owner's key, then installs yi to ~/.local/bin and its
runtime to ~/.yi; Apple-silicon Macs and x86_64 Linux, and | bash -s -- --help prints that key. By hand:
v=X.Y.Z t=aarch64-apple-darwin; base=https://github.com/jackmaxwil/yi/releases/download/v$v; a=yi-$v-$t.tar.gz
curl -fLO "$base/$a" -O "$base/$a.sig" -O "$base/SHA256SUMS"; shasum -a 256 -c SHA256SUMS --ignore-missing
echo 'jackmaxwil-release ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAaFfxFxxkIpL0TuZcvkcLpzT164hwIaCbzyFnVkAMX7' > allowed_signers
ssh-keygen -Y verify -f allowed_signers -I jackmaxwil-release -n yi-release -s "$a.sig" < "$a"
tar -xzf "$a" && "./yi-$v-$t/install.sh"yi ask --model faux/faux-1 "hello" # offline, no key: prints "faux: hello"
yi login openrouter # paste a key at the prompt
yi setup # default model and permission mode
yi "what does this repo do?" # one answer
yi # the console; --solo: one chatyi login openrouter # also openai, google: an API key, pasted or piped on stdin
yi login cursor # browser sign-in; --no-browser skips opening it
yi login kimi # also anthropic, openai-codex: a profile you write firstThe OAuth three read ~/.yi/oauth/<provider>.json (templates); tokens land in
~/.yi/providers/tokens/<provider>.json (0600), not the config, and *_API_KEY wins when set.
yi plugin list
yi plugin add --all # or one: ripwire, chrome
yi plugin syncripwire 0.6.5 is a code map (an edit's broken callers, the code a task touches; 16 skills);
chrome 155.0.8059.39 is a headless shell for the browser pane, both pinned in ~/.yi/plugins.
A skill is a directory with a SKILL.md, read from .yi/skills, .agents/skills, .pi/skills or
.claude/skills, then ~/.yi/skills; $name points the model at one.
yi debug config # ~/.yi/config.json, secrets redactedStrict: an unknown key is an error that names it. Every key is in YI_DESIGN.md §17.1.
| key | default | meaning |
|---|---|---|
model, thinking |
none, medium |
provider/id; off to max effort |
models.summarizer, .advisor, .autoReview |
main, off, off | compaction, titles; naming one turns it on |
models.classifier |
off | TypeSafe's Jev through OpenRouter (typesafe/jev-1.13) as the permission and skill classifier; typed messages and judged commands leave the machine |
routing |
none | OpenRouter's provider object |
permissions.mode, permissions.allow |
auto, none |
ask, auto or yolo; calls that run unasked |
tui.pace |
100 | reveal speed, percent |
rlm.maxDepth |
1 | subagent nesting, 1 to 3 |
kernel.prewarm, mcp.enabled, lanes.enabled |
true, false, true | kernel at open; the MCP CLI; a worktree per root |
| environment | for |
|---|---|
YI_PREFIX, YI_VERSION, YI_RELEASE_BASE |
install directory; the release it reads |
YI_KERNEL_VENV, YI_KERNEL_PYTHON, YI_BIN |
the kernel's venv; the yi it calls |
YI_TRACE, YI_CLAUDE_HOOKS, YI_CLAUDE_HOOKS_FILES |
a profiler trace; Claude Code tool hooks |
YI_LEVERS, YI_FIXED_IDS, YI_BLESS, YI_FAKE_RIPWIRE, YI_WARM, YI_REVIEW_MODEL, YI_ROUND_AUTHORS, YI_SIGNING_KEY, YI_ALLOWED_SIGNERS |
development: levers, ids, goldens, fakes, review bot, signing |
| verb | |
|---|---|
ask rpc acp serve console tui |
one turn; stdio protocols; daemon; workspace; solo TUI |
plan todo why |
plan ops; the newest todo list; a line to its goal |
sessions stats memory fetch catalog |
sessions; token stats; memories; one URL |
undo lanes trust gate doctor gc debug |
undo; worktrees; trust; policy; repair |
login logout setup plugin update version mcp |
credentials; plugins; release; MCP |
Flags: --model, --json, --schema, --yolo, --continue, --deadline;
yi --help has all.
$ yi todo # the newest todo list
$ yi why crates/cli/src/main.rs:42 # walk a line back to the words that asked for itA plan is a goal and a graph of todos, from the plan tool or a cell's Plan.create; a todo with a
contract closes only when its check passes. Design: YI_DESIGN.md §13.
answers = await asyncio.gather(*(rlm.ask("Can this function panic? Quote the line.", [url]) for url in urls))
h = await rlm.run("Port the parser to the new token type", role="worker", isolation="worktree")
result = await h.result(timeout=420)A reader gets read, grep and three turns; a worker edits too; a root is a session.
isolation="worktree" gives a child a worktree. Design: YI_DESIGN.md §11.
$ yi ask --model faux/faux-1 --json --no-deltas hello | jq -r .type | tr '\n' ' '
agent_start turn_start message_start message_end message_start message_end turn_end agent_end finalyi ask exits 0 with an answer, 1 when the run failed, 2 when refused before starting, 3 when the
answer misses --schema, 4 on a denied tool or a quota:
if yi ask --model faux/faux-1 --schema '{"type":"object"}' "list the risks as JSON" > risks.json
then echo "risks.json written"; else echo "yi exited $?"; fi # yi exited 3: faux answers no JSONgit diff | yi ask - reads the prompt from stdin; --continue resumes the newest session here.
With {"mcp": {"enabled": true}}, yi mcp --json reaches an MCP server once.
yi ask --model faux/faux-1 --json "hello" # the event stream
yi acp # ACP v2
yi serve # the daemon's socketA full SDK is coming; today build on those, or on ~/.yi/sessions/ (Pi's v4 JSONL).
just check # fmt, clippy, the guardrails, the testsA private forge is the source of truth; this is a read-only mirror of its main, and contributions
come by invitation (CONTRIBUTING.md).
Session, tool, kernel, URL, child, todo, plan, contract and lane compose every feature (YI_DESIGN.md §3), and every cut of model-facing text names its cap.
auto mode sandboxes commands with Seatbelt; .git and credential stores stay denied even in
yolo.
just dev # build and start yi
just test-quick # the workspace without its slowest tests
just build-dist # the release buildYI_DESIGN.md is the law, ARCHITECTURE.md the map.
Apache License 2.0 in LICENSE; copyright Jack Mazac and AiBridge LLC, in NOTICE. vendor/ keeps its upstream licenses.