Runs
A Run is one execution of a Runtime, from start until it stops or fails. It is the record of that execution.
Every trace, event, recording, and usage entry for the execution is keyed by
the Run ID. A Run response exposes that identifier as id; Run-scoped methods
take it as runId. Use runtimeId to identify the Runtime that produced the
Run.
The runtime controls the Run lifecycle:
- Creating an ephemeral runtime normally opens a Run immediately.
- Starting a stopped runtime opens a Run and returns its
runId. - Browser connections, Tools, ToolCalls, and Agent turns contribute to that Run.
- Stopping the runtime ends the Run.
Find Runs
List Runs for a Space or read one by ID:
Run status is active, stopped, or failed. A failed Run includes a failure
code and message when the platform has one.
Run fields
Full Run shape
Runtime and Run are different
The Runtime is the durable automation resource. The Run is one session of that Runtime. An ephemeral Runtime normally has one Run; a profile-backed Runtime can have many Runs over its lifetime.
Use the Run ID when you need to inspect the trace, read raw events, follow live activity, review an audit record, or connect files and artifacts to one execution.
Trace and events
BCTRL exposes two complementary views of a Run:
Read the trace
Trace spans can have these kinds:
runtime, agent, tool, llm, browser, network, file, and system.
parentId connects nested spans into a causal tree. Use resourceType and
resourceId to connect a span back to a runtime, ToolCall, Agent turn, file,
or other platform resource.
Read raw events
Events include a source such as control-plane, browser-host, runtime-agent,
gateway, cdp, or webdriver. They may reference the trace span that caused
the event through spanId.
Trace and event fields
Trace kind is one of runtime, agent, tool, llm, browser, network,
file, or system. Event source identifies where the fact came from.
Full trace and event shapes
Stream a Run
The unified stream emits normalized frames as the Run changes:
For a reconnect, pass the last received stream ID as after so the server can
continue from that point. The stream ends when the Run ends.
Use trace to answer “what work caused this result?”, events to answer “what did the runtime report?”, and the stream to answer “what is happening now?”.
See Connect with CDP for attaching a browser client to the active Run.

