Protocol

Commands

type JourneyDevtoolsCommand =
  | { type: "startJourney" }
  | { type: "goToNextStep" }
  | { type: "terminateJourney" }
  | { type: "completeJourney" }
  | { type: "goToStepById"; stepId: string }
  | { type: "goToPreviousStep"; steps?: number }
  | { type: "goToLastVisitedStep" }
  | { type: "send"; event: { type: string; payload?: unknown } }
  | { type: "resetJourney" }
  | { type: "clearStepError"; stepId?: string }
  | { type: "getExecutionPaths"; options?: { maxDepth?: number; maxPaths?: number } };

Register Metadata

Protocol version is 4.

Register envelopes now include capability metadata:

• meta.capabilities.commands
• meta.capabilities.observe
• meta.capabilities.executionPaths
• meta.capabilities.persistence (optional bridge-supplied metadata)

Compatibility Contract

Protocol version is the compatibility boundary.

• Incompatible command, envelope, or payload shape changes require a protocol version bump.
• Panel and bridge consumers should upgrade together across protocol-version changes.
• Additive metadata and additive fields are preferred over mutating existing shapes in place.
• The bridge is tooling-facing. The runtime contract still lives in Core and React.

Bridge Envelopes

Bridge-origin envelopes now include:

• register
• snapshot
• observation
• commandResult
• executionPathsResult
• commandError
• unregister

Snapshot Payload

Snapshots sent by bridge include:

• currentStepId
• history.timeline
• history.index
• context
• visited
• status
• async

Observation Payload

observation envelopes mirror core JourneyObservationEvent field names, with nested payloads/errors cloned to transport-safe JSON values.

Execution Path Query Result

executionPathsResult envelopes return:

• result.paths
• result.truncated
• result.cyclesDetected

See the shared Stability Contract for the broader support guarantees.