Restatealpha

Run Motoko actors as Restate virtual objects, with state in Restate and delayed calls as timers.

Each actor key is a Restate virtual object. Restate delivers its messages one at a time and keeps its state; timers are Restate delayed calls.

You also need the moxzi SDK and hosts bundles; see Actor platforms.

Prerequisites#

Docker, for the Restate server. The host is prebuilt
OpenSSL and Python 3, used once to create the local Restate request-identity key

Create and run a project#

moxzi host new restate hello

cd hello
ONCE=1 ./run.sh

actor.mo -> actor.wasm + actor.did (245563 bytes, 1 file(s), 50 steps, 0.66s)
Counter/1.inc() -> [1]

Run it a second time. The host is a new process, and the actor's state comes back from the platform's store:

ONCE=1 ./run.sh

actor.mo -> actor.wasm + actor.did (245563 bytes, 1 file(s), 50 steps, 0.62s)
Counter/1.inc() -> [2]

ONCE=1 exits after the demo. Without it, the host keeps running on port 8090 (set PORT to change it), and you can call any key:

curl -X POST localhost:8090/actors/Counter/2/method/inc \
  -H 'content-type: application/json' -d '[]'

--example ledger and --example saga work on Restate too; see Examples.

The project#

Path	Contents
`actor.mo`	The `Counter` actor type. Each key `Counter/ID` is a separate actor
`host/`	moxzi's Restate adapter. It's yours to change
`run.sh`	Builds the actor and the host, starts what Restate needs, and runs the demo

Change actor.mo and run ./run.sh again. New keys use the new code. Existing keys keep their code until they're upgraded; host/README.md describes upgrades.

How it maps#

	Handled by
One message at a time per key	The Restate virtual object
Actor state	Restate state, in the Restate server container `moxzi-hello-restate` (ports 18080 and 19080; set `RESTATE_PORT` to move them)
Durable timers	Restate delayed calls

State lives in the Restate server container, not the project directory. Remove it with docker rm -f moxzi-hello-restate to start over.

The project also contains platform-runtimes.env, which pins Restate by version and architecture-specific OCI digest. run.sh verifies the image ID and server-reported version and records them in .restate/runtime-provenance.log. If a same-named container was created from different bytes, startup stops before that container runs. Back up or export its state and follow the Restate migration procedure before replacing it. MOXZI_RESTATE_IMAGE_OVERRIDE accepts only an immutable digest and marks the run outside Moxzi's tested compatibility pair.

Configuration#

Variable	Default	Effect
`PORT`	`8090`	The host's HTTP port
`MOXZI_HOST_TOKEN`	random	Token for the host's control endpoints (`/_moxzi/*`)
`MOXZI_RESTATE_SDK_ADDR`	`127.0.0.1:<PORT+300>`	Exact Restate SDK listen address; use only an address Restate can reach
`MOXZI_RESTATE_SDK_HOST`	`127.0.0.1`	SDK listen host when `MOXZI_RESTATE_SDK_ADDR` is unset; the generated Docker run sets `0.0.0.0`
`MOXZI_RESTATE_REACH`	local SDK URL, or `host.docker.internal:<PORT+300>` for a remote bind	URL registered with Restate
`MOXZI_RESTATE_IDENTITY_KEY`	generated for the local server	Restate `publickeyv1_...` key used to verify every raw SDK request; mandatory off loopback
`MOXZI_RESTATE_PREVIOUS_IDENTITY_KEY`	unset	Previous public key accepted during a controlled rotation

The matching private PEM is configured on the Restate server through RESTATE_REQUEST_IDENTITY_PRIVATE_KEY_PEM_FILE. The generated project keeps it in the gitignored .restate/ directory. For an external Restate deployment, create and protect your own ED25519 PKCS#8 key, configure its private half on Restate, and give only the encoded public half to the host. Remote SDK binding also requires a nonempty MOXZI_HOST_TOKEN; startup fails if either boundary is missing.

For a rolling key change, first deploy hosts with the new public key as MOXZI_RESTATE_IDENTITY_KEY and the old one as MOXZI_RESTATE_PREVIOUS_IDENTITY_KEY. Then switch Restate to the new private key and remove the previous key after old invocations have drained.