Configure cf-orbs

The only config you edit is cf-orbs.config.jsonc in your project directory. cf-orbs init writes it, and the format is JSONC: JSON with comments and trailing commas.

Change a setting

Edit the file
Open cf-orbs.config.jsonc and change a value. For example:
```
{
  "maxRunning": 10,
  "warmMinutes": 0
}
```
Keys you leave out take their defaults. See the config reference.
Deploy
```
npx cf-orbs deploy
```
deploy checks the file first, and a bad value stops it with one Failed: ... — fix: ... line.

In a Workers Builds project, don’t run deploy. See Install with Workers Builds.

What the check rejects

The CLI checks the file before it deploys. The Worker applies the same range rules, so a config that the CLI accepts won’t fail in the Worker. Only the CLI rejects unknown keys; the Worker ignores them. The CLI check stops on:

An unknown key. This catches typos.
A number outside its range.
instance of lite, basic, or dev. They are too small for the orb image.
Memory below 3 GiB for each vCPU.
checkpointMinutes between 1 and 14.
fastTmpfsGb larger than the orb memory in GiB minus 3.
A name that is not lowercase letters, digits, and dashes (63 characters at most).

When a change reaches running orbs

After cf-orbs deploy, an orb that is awake keeps the old Worker code until it pauses (that’s how Cloudflare works). A config change reaches such an orb at the same time as the code.

Use a second install

The name key sets the Worker name. A second install, for example one with another orb size, needs another name and another Amp provider token. Run cf-orbs init --name <worker> in a new directory.

Decide the main settings

Goal	Setting
Lower the cost of each hour	`instance` (see Change the orb size)
Limit the bill from many threads	`maxRunning`, `maxAwakeHours`
Wake faster after a pause	`warmMinutes` (default 10)
Lose less work when Cloudflare stops a container	`checkpointMinutes`
Speed up caches and temp files	`fastTmpfsGb` (mounts `/mnt/fast`)
Raise the chance of a host that has the image	`prewarm`
Keep new threads from using a stale project snapshot	`projectSnapshotRefresh`

Commit cf-orbs.config.jsonc after a change, because you can’t make it again. See Back up and restore.