Install

World has no packaged release. You build it from source and point it at two pinned AILANG binaries.

Requirements

• Go 1.26.6 (the version in go.mod and CI). The build fetches the Go module github.com/sunholo-data/ailang at v0.47.2, which provides the MCP and A2A wire handlers.
• git, curl, python3 (the runbooks use it to build commit JSON and parse SSE).
• macOS or Linux. The tool-confinement facts were measured on macOS (APFS); CI runs on Linux.

Build the two programs

git clone https://github.com/sunholo-data/ailang-world
cd ailang-world
go build -o /tmp/ailang-worldd ./cmd/ailang-worldd
go build -o /tmp/world-publish ./cmd/world-publish

Binary	What it is
ailang-worldd	The daemon (serve), its bounded client verbs, and session mint/revoke
world-publish	The attended operator entrypoint: transition-registry publish and the world/core package publish

world-publish is a separate program on purpose: nothing CI or the daemon runs is one flag away from an irreversible write.

The two pinned AILANG binaries

World uses two AILANG releases for two different jobs. Both are checked by version at startup.

Name in the docs	Release	Used for	Passed as
PIN	AILANG v0.41.0 (commit 24ee108)	The interpreter that runs every transition (plan and finish phases), type-checks transition sources at publish time, and builds/verifies world/core	serve --ailang-bin, world-publish transitions --ailang-bin
TOOL	AILANG v0.52.1 (commit c68ded4)	The binary the coding tools run inside the episode worktree (policy-tool and run --policy)	serve --tool-ailang-bin

Why two pins.

• PIN is the replay pin. Its content hash is written into every log entry and every registry descriptor, so it only moves deliberately. v0.41.0 is also the compiler the world/core golden ready-packet names (frozenCompilerVersion in cmd/world-publish), and CI verifies the .ail sources against it.
• TOOL is a separate, archived, hash-verified binary chosen for its confinement behaviour. The tool confinement (sandbox, .git protection including the macOS .GIT case-fold fix that landed in v0.50.1, --chdir, --args-json) and the four run outcome shapes were measured on v0.51.0 and re-proved on exactly v0.52.1 (the pin since row 135 M0). The daemon refuses any other release for --tool-ailang-bin: a different binary changes the measured facts, and World never widens to an unmeasured one (residual R-SE-8).

Install them at the paths the runbooks use. Release assets are named <os>.<arch>.ailang.tar.gz, each with a .sha256 file (CI uses linux.x64; the tool binary was measured with darwin.arm64). For example, on Apple silicon:

mkdir -p ~/.pinned-ailang ~/.pinned-ailang-tools/v0.52.1
cd "$(mktemp -d)"

base=https://github.com/sunholo-data/ailang/releases/download/v0.41.0
curl -fsSL -o pin.tar.gz "$base/darwin.arm64.ailang.tar.gz"
curl -fsSL -o pin.tar.gz.sha256 "$base/darwin.arm64.ailang.tar.gz.sha256"
echo "$(cut -d' ' -f1 pin.tar.gz.sha256)  pin.tar.gz" | shasum -a 256 -c -
tar -xzf pin.tar.gz -C ~/.pinned-ailang ailang

base=https://github.com/sunholo-data/ailang/releases/download/v0.52.1
curl -fsSL -o tool.tar.gz "$base/darwin.arm64.ailang.tar.gz"
curl -fsSL -o tool.tar.gz.sha256 "$base/darwin.arm64.ailang.tar.gz.sha256"
echo "$(cut -d' ' -f1 tool.tar.gz.sha256)  tool.tar.gz" | shasum -a 256 -c -
tar -xzf tool.tar.gz -C ~/.pinned-ailang-tools/v0.52.1 ailang

export PIN=$HOME/.pinned-ailang/ailang
export TOOL=$HOME/.pinned-ailang-tools/v0.52.1/ailang
$PIN --version && $TOOL --version

The first line of each --version must read AILANG v0.41.0 and AILANG v0.52.1.

Keep the pins out of /tmp

macOS clears /tmp on reboot. Older runbooks used /tmp/ailang-v0300/ailang (v0.30.0, the pin before 2026-09-21); that path and version are retired. Use the durable paths above.

Never use a development build

Run World against released, tagged binaries only — never a -dirty build and never whatever ailang happens to be on PATH.

Optional: an examples corpus

The examples-search tool needs an AILANG examples corpus that the operator names. v0.52.1 embeds a corpus, but World does not fall back to it. $TOOL examples download fills ~/.ailang/examples, which serve uses by default when it exists. See Coding tools.

Before you run anything

Unset the registry credential in the shell that runs ailang-worldd:

unset AILANG_REGISTRY_API_KEY

With it set, every ailang-worldd command, client verbs included, refuses to start (exit 2). The registry is immutable, so an ambient key would hand unrecallable publish authority to every process World starts. Keep the key in a mode-0600 file outside the working tree instead.

Next: Your first world.