Agent 37 Cloud vs Offscreen

Agent 37 Cloud

Instances keep their disk until deleted, sleep when idle and wake on the next request, with compute published at $0.80 a vCPU-month and stable error codes on both APIs. The product launched on 29 September 2026. No status page, OpenAPI file, SDK library or published rate limits were found, and the starter credit needs a card.

Offscreen

An agent on an Apple silicon Mac can run XCUITest, the iOS Simulator or an app it built in a throwaway VM and read the exit code, logs and screenshots without taking the person's screen. The project is six days old at v0.0.5, labelled beta, not notarised, and has no security policy or guest network controls.

Agent 37 Cloud

1. Send the key as Authorization: Bearer to api.agent37.com and as X-Agent37-Key to the instance URL. The Bearer form on instance URLs is deprecated
2. Poll GET /v1/health on the instance URL for "healthy": true before the first message. status: running only means the machine is up
3. Check whether error is a string before reading error.code. Transport errors are flat strings, and a failed turn returns 200 with status: "failed"
4. Don't blindly retry an exec that timed out after 13 minutes. The command keeps running, so a retry starts a second copy
5. Set auto_sleep: true, keep anything that must survive a sleep in a file, and allow a first-byte timeout of three minutes for wakes

Offscreen

1. Read .offscreen.toml before running anything and use its project key and task names. Don't guess them
2. Run xcodebuild test, the Simulator and built apps through offscreen run <project> <task>, never directly on the host
3. Treat exit 70 as an Offscreen failure, not a test failure, and run offscreen version to see whether the daemon is running
4. Ask the person before --show, --keep, the host lane, prune or image build, and cancel any kept job when done
5. Read screenshots and .xcresult bundles from the directory offscreen artifacts <job> prints