@devicerail/yaml-adapter

Optional DR-045 compatibility adapter. It parses a deliberately bounded, JSON-shaped YAML plan and compiles it into sequential calls on an already owned, already-negotiated @devicerail/client instance.

The adapter is not a workflow engine. It has no Driver, daemon, Rust, AI, prompt, retry, branching, interpolation, or filesystem authority. YAML never enters the DeviceRail kernel.

version: devicerail/v1
steps:
  - id: select
    method: device.select
    params:
      deviceId: android-emulator-5554
  - id: connect
    method: device.connect
    params: {}
  - id: tap
    method: device.execute
    params:
      id: 11111111-1111-4111-8111-111111111111
      name: tap
      arguments: {x: 20, y: 40}

device.execute requires a caller-supplied, device-aware action-protection classifier and a fixed selected device (from device.select or initialDeviceId). Unknown and protected actions are rejected at compile time. Immediately before execution the adapter re-selects that device, verifies the connection-local route through devices.list, and re-reads device.capabilities; a missing or newly protected action fails before its arguments are sent. The verified device.execute call is started in the same JavaScript continuation as that final capability check. A client used for YAML execution must not be shared with non-adapter calls that can race device.select. The caller remains responsible for device and Session lifecycle.

Within the YAML adapter's closed method allowlist, timeoutMs is accepted only for these five request-controlled methods: device.capabilities, device.connect, device.disconnect, device.execute, and device.observe. An execution AbortSignal is passed only to those methods; for all other methods it is observed between sequential steps, matching the public client's cancellation contract.

Parsing uses the js-yaml JSON schema and then applies independent byte, depth, node, collection, key, number, duplicate-ID, method, and timeout bounds. Custom tags, object aliases/cycles, prototype keys, duplicate YAML keys, unknown plan fields, system.hello, events.subscribe, and direct request.cancel calls fail closed. Execution also requires the opaque, immutable plan returned by compileYamlPlan rather than accepting a manually constructed lookalike. Trust is tracked in a module-private WeakSet, so copying symbols or inheriting from a valid plan does not authorize a new plan.