Streaming events

When you enable streaming: true in SessionConfig, session behavior is delivered as incremental events.

SessionEvent page explains Laravel-specific helpers for the SessionEvent class itself. This page is a type-and-payload reference for each event.

Overview

Copilot agent behavior (reasoning, messages, tool execution, permission checks, and more) flows through session events.

Ephemeral event: Real-time only. Not persisted in session logs.
Persisted event: Stored in session logs and replayed when resuming.
Delta event: Fragment event (deltaContent, etc.) that you stitch into full content.
parentId chain: Each event links to its previous event.

Event envelope (common fields)

Field	Type	Description
`id`	`string`	Event ID (UUID v4)
`timestamp`	`string`	ISO 8601 timestamp
`parentId`	`string \| null`	Previous event ID (`null` for first event)
`ephemeral`	`boolean?`	`true` when the event is ephemeral
`type`	`string`	Event type
`data`	`object`	Event-specific payload

Laravel subscription example

use Revolution\Copilot\Contracts\CopilotSession;
use Revolution\Copilot\Enums\SessionEventType;
use Revolution\Copilot\Facades\Copilot;
use Revolution\Copilot\Types\SessionConfig;
use Revolution\Copilot\Types\SessionEvent;

Copilot::start(function (CopilotSession $session): void {
    // All events
    $session->on(function (SessionEvent $event): void {
        info($event->type(), $event->toArray());
    });

    // Specific event type
    $session->on(SessionEventType::ASSISTANT_MESSAGE_DELTA, function (SessionEvent $event): void {
        echo $event->deltaContent();
    });

    $session->sendAndWait(prompt: 'Explain key Laravel strengths');
}, config: new SessionConfig(streaming: true));

Major event categories

Assistant events

`assistant.turn_start`

Turn starts.

turnId (required)
interactionId (optional)

`assistant.intent` (ephemeral)

Current execution intent (for example, Exploring codebase).

intent (required)

`assistant.reasoning`

Completed reasoning block.

reasoningId (required)
content (required)

`assistant.reasoning_delta` (ephemeral)

Reasoning text delta.

reasoningId (required)
deltaContent (required)

`assistant.message`

Completed assistant message. Common fields:

messageId (required)
content (required)
toolRequests (optional)
reasoningOpaque / reasoningText / encryptedContent (optional)
phase / outputTokens / interactionId (optional)
parentToolCallId (optional)

`assistant.message_delta` (ephemeral)

Message body delta.

messageId (required)
deltaContent (required)
parentToolCallId (optional)

`assistant.turn_end`

Turn ends.

turnId (required)

`assistant.usage` (ephemeral)

Per-API-call usage metrics. Common fields:

model (required)
inputTokens / outputTokens / cost / duration (optional)
apiCallId / providerCallId (optional)
quotaSnapshots / copilotUsage (optional)

`assistant.streaming_delta` (ephemeral)

Low-level stream progress.

totalResponseSizeBytes (required)

Tool execution events

`tool.execution_start`

Tool execution starts.

toolCallId (required)
toolName (required)
arguments / mcpServerName / mcpToolName / parentToolCallId (optional)

`tool.execution_partial_result` (ephemeral)

Partial output while tool runs.

toolCallId (required)
partialOutput (required)

`tool.execution_progress` (ephemeral)

Progress message.

toolCallId (required)
progressMessage (required)

`tool.execution_complete`

Tool execution ends (success/failure).

toolCallId (required)
success (required)
result (on success)
error (on failure)
toolTelemetry / parentToolCallId (optional)

`tool.user_requested`

Tool call explicitly requested by user.

toolCallId (required)
toolName (required)
arguments (optional)

Session lifecycle events

`session.start`

Session start. For Cloud Sessions, it is safest to send the first prompt after confirming a session.start whose producer is copilot-agent.

producer (optional)

`session.idle` (ephemeral)

Processing finished. Waiting for next input.

backgroundTasks (optional)

`session.error`

Error during session processing.

errorType (required)
message (required)
stack / statusCode / providerCallId (optional)

`session.compaction_start`

Context compaction starts (data is an empty object).

`session.compaction_complete`

Context compaction completes. Common fields:

success (required)
error (optional)
preCompactionTokens / postCompactionTokens (optional)
summaryContent / checkpointPath (optional)

`session.title_changed` (ephemeral)

Auto title update.

title (required)

`session.context_changed`

Working context changed.

cwd (required)
gitRoot / repository / branch (optional)

`session.info`

Session information such as a remote URL.

infoType (required)
url (optional, e.g. when infoType is remote)

`session.remote_steerable_changed`

Indicates that remote steerability from Mission Control has changed.

remoteSteerable (optional)

`session.usage_info` (ephemeral)

Context window usage status.

tokenLimit (required)
currentTokens (required)
messagesLength (required)

`session.task_complete`

Task completion notification.

summary (optional)

`session.shutdown`

Session shutdown. Common fields:

shutdownType (required)
errorReason (optional)
totalPremiumRequests / totalApiDurationMs (required)
codeChanges / modelMetrics (required)

Permission and user input events

`permission.requested` (ephemeral)

Permission request.

requestId (required)
permissionRequest (required)

permissionRequest.kind values:

shell
write
read
mcp
url
memory
custom-tool

`permission.completed` (ephemeral)

Permission resolution result.

requestId (required)
result.kind (required)

`user_input.requested` (ephemeral)

Question asked to user.

requestId (required)
question (required)
choices / allowFreeform (optional)

`user_input.completed` (ephemeral)

User input completed.

requestId (required)

`elicitation.requested` (ephemeral)

Structured input request (form).

requestId (required)
message (required)
requestedSchema (required)

`elicitation.completed` (ephemeral)

Structured input completed.

requestId (required)

Sub-agent and skill events

`subagent.started`

toolCallId (required)
agentName / agentDisplayName / agentDescription (required)

`subagent.completed`

toolCallId (required)
agentName / agentDisplayName (required)

`subagent.failed`

toolCallId (required)
agentName / agentDisplayName (required)
error (required)

`subagent.selected`

agentName (required)
agentDisplayName (required)
tools (required, can be null)

`subagent.deselected`

Returns to default agent (data is an empty object).

`skill.invoked`

name / path / content (required)
allowedTools / pluginName / pluginVersion (optional)

Other events

`abort`

reason (required)

`user.message`

content (required)
transformedContent / attachments / source / agentMode / interactionId (optional)

`system.message`

content (required)
role (required)
name / metadata (optional)

`external_tool.requested` (ephemeral)

requestId / sessionId / toolCallId / toolName (required)
arguments (optional)

`external_tool.completed` (ephemeral)

requestId (required)

`exit_plan_mode.requested` (ephemeral)

requestId / summary / planContent / actions / recommendedAction (required)

`exit_plan_mode.completed` (ephemeral)

requestId (required)

`command.queued` (ephemeral)

requestId (required)
command (required)

`command.completed` (ephemeral)

requestId (required)

Typical event order

assistant.turn_start
├── assistant.intent (ephemeral)
├── assistant.reasoning_delta (ephemeral, repeated)
├── assistant.reasoning
├── assistant.message_delta (ephemeral, repeated)
├── assistant.message
├── assistant.usage (ephemeral)
├── [permission / tool.* loops if needed]
assistant.turn_end
session.idle (ephemeral)

Quick reference of all events

Event Type	Ephemeral	Category
`session.start`		Session
`assistant.turn_start`		Assistant
`assistant.intent`	✅	Assistant
`assistant.reasoning`		Assistant
`assistant.reasoning_delta`	✅	Assistant
`assistant.streaming_delta`	✅	Assistant
`assistant.message`		Assistant
`assistant.message_delta`	✅	Assistant
`assistant.turn_end`		Assistant
`assistant.usage`	✅	Assistant
`tool.user_requested`		Tool
`tool.execution_start`		Tool
`tool.execution_partial_result`	✅	Tool
`tool.execution_progress`	✅	Tool
`tool.execution_complete`		Tool
`session.idle`	✅	Session
`session.error`		Session
`session.compaction_start`		Session
`session.compaction_complete`		Session
`session.title_changed`	✅	Session
`session.context_changed`		Session
`session.info`		Session
`session.remote_steerable_changed`		Session
`session.usage_info`	✅	Session
`session.task_complete`		Session
`session.shutdown`		Session
`permission.requested`	✅	Permission
`permission.completed`	✅	Permission
`user_input.requested`	✅	User Input
`user_input.completed`	✅	User Input
`elicitation.requested`	✅	User Input
`elicitation.completed`	✅	User Input
`subagent.started`		Sub-Agent
`subagent.completed`		Sub-Agent
`subagent.failed`		Sub-Agent
`subagent.selected`		Sub-Agent
`subagent.deselected`		Sub-Agent
`skill.invoked`		Skill
`abort`		Control
`user.message`		User
`system.message`		System
`external_tool.requested`	✅	External Tool
`external_tool.completed`	✅	External Tool
`command.queued`	✅	Command
`command.completed`	✅	Command
`exit_plan_mode.requested`	✅	Plan Mode
`exit_plan_mode.completed`	✅	Plan Mode

Official streaming events reference
Laravel event class details: SessionEvent
Streaming implementation patterns: Streaming

Documentation Index