Events

Monitors produce a stream of events on each execution. Every event object has an event_type field that discriminates the variant:

`event_type`	Description
`event_stream`	A new material change detected by an event_stream monitor. See Event Stream Quickstart.
`snapshot`	A change to the monitored task output detected by a snapshot monitor. See Snapshot Quickstart.
`completion`	Execution completed with no new detections.
`error`	Execution failed.

A run maps to exactly one outcome. Runs with detected events do not also emit a completion event.

Event Stream Events (`event_type: "event_stream"`)

Emitted when an event_stream monitor detects a new material change. Each event is an append-only entry in the monitor’s log.

Field	Type	Description
`event_id`	string	Stable identifier. Safe to use for client-side deduplication across pagination and retries.
`event_group_id`	string	ID of the event group that owns this event.
`event_date`	string \| null	Date the event was produced (ISO 8601: `YYYY-MM-DD` or partial).
`event_type`	`"event_stream"`	Discriminant.
`output`	object	Text or JSON output describing the detected change. Includes `type`, `content`, and `basis`.

Snapshot Events (`event_type: "snapshot"`)

Emitted when a snapshot monitor detects that the monitored task output has changed. Contains both what changed and what it was before.

Field	Type	Description
`event_id`	string	Stable identifier. Safe to use for client-side deduplication.
`event_group_id`	string	ID of the event group that owns this event.
`event_date`	string \| null	Date the event was produced (ISO 8601).
`event_type`	`"snapshot"`	Discriminant.
`changed_output`	object	Partial output containing only the fields that changed, each with `basis` (reasoning and citations).
`previous_output`	object	Full output from the prior run, for comparison.

Event Basis

Every detected event (event_stream and snapshot) includes a basis field in its output with citations, reasoning, and a confidence level—the same transparency framework used in Task API outputs. See Research Basis for the full schema.

Accessing Events

Events can be received via webhooks (recommended) or retrieved via the API.

Webhooks (recommended)

Lowest latency, push-based delivery. Subscribe to monitor.event.detected, monitor.execution.completed, and monitor.execution.failed. See Webhooks for setup details.

API

List all events for a monitor, newest first:

curl --request GET \
  --url "https://api.parallel.ai/v1/monitors/${MONITOR_ID}/events" \
  --header "x-api-key: $PARALLEL_API_KEY"

import os
from parallel import Parallel

client = Parallel(api_key=os.environ["PARALLEL_API_KEY"])

result = client.monitor.events(monitor_id)
for event in result.events:
    print(event.event_id, event.event_type)

import Parallel from "parallel-web";

const client = new Parallel({ apiKey: process.env.PARALLEL_API_KEY });

const result = await client.monitor.events(monitorId);
for (const event of result.events) {
  console.log(event.event_id, event.event_type);
}

Returns up to the ~300 most recent executions. Use next_cursor for pagination. Pass include_completions=true to include no-change runs. Filter by execution using the event_group_id query parameter:

curl --request GET \
  --url "https://api.parallel.ai/v1/monitors/${MONITOR_ID}/events?event_group_id=${EVENT_GROUP_ID}" \
  --header "x-api-key: $PARALLEL_API_KEY"

import os
from parallel import Parallel

client = Parallel(api_key=os.environ["PARALLEL_API_KEY"])

result = client.monitor.events(
    monitor_id,
    event_group_id=event_group_id,
)
for event in result.events:
    print(event.event_id, event.event_type)

import Parallel from "parallel-web";

const client = new Parallel({ apiKey: process.env.PARALLEL_API_KEY });

const result = await client.monitor.events(monitorId, {
  event_group_id: eventGroupId,
});
for (const event of result.events) {
  console.log(event.event_id, event.event_type);
}

Use the event_group_id from the webhook payload directly as the query parameter to fetch all events from a specific execution.

Getting started

Web Tools

Web Agents

Developer Tools

Platform Integrations

Data Integrations

Additional Resources

Event Stream Events (`event_type: "event_stream"`)

Snapshot Events (`event_type: "snapshot"`)

Event Basis

Accessing Events

Webhooks (recommended)

API

​Event Stream Events (event_type: "event_stream")

​Snapshot Events (event_type: "snapshot")

​Event Basis

​Accessing Events

​Webhooks (recommended)

​API

Event Stream Events (`event_type: "event_stream"`)

Snapshot Events (`event_type: "snapshot"`)

Event Basis

Accessing Events

Webhooks (recommended)

API