Docs / Actor platforms / Cloudflare Durable Objects

Cloudflare Durable Objectsalpha

Run Motoko actors as Cloudflare Durable Objects, with Durable Object storage and alarms.

Each actor key is a Durable Object. Cloudflare delivers its messages one at a time and stores its state; timers are Durable Object alarms. run.sh uses wrangler dev --local.

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

Prerequisites#

Node.js and npm. run.sh installs Wrangler locally

Create and run a project#

moxzi host new cloudflare hello

cd hello
ONCE=1 ./run.sh

actor.mo -> actor.wasm + actor.did (245563 bytes, 1 file(s), 50 steps, 0.76s)
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, 0.77s)
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 Cloudflare Durable Objects too; see Examples.

The project#

Path	Contents
`actor.mo`	The `Counter` actor type. Each key `Counter/ID` is a separate actor
`host/`	moxzi's Cloudflare Durable Objects adapter. It's yours to change
`run.sh`	Builds the actor and the host, starts what Cloudflare Durable Objects 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 Durable Object
Actor state	Durable Object storage (`wrangler-state/` locally)
Durable timers	Durable Object alarms

Workers can't compile wasm at run time, so the adapter bundles every actor module ahead of time. Build actors with --compact-rts to keep memory inside the 128 MB isolate limit. Locally, wrangler dev runs every Durable Object in one isolate.

Configuration#

Variable	Default	Effect
`PORT`	`8090`	The host's HTTP port
`MOXZI_HOST_TOKEN`	random	Token for the host's control endpoints (`/_moxzi/*`)