Event Reference

This page documents all event types in the Everruns event protocol.

Input Events

input.message

Emitted when a user message is submitted to the session.

Field	Type	Description
message	Message	The user message object

{
  "type": "input.message",
  "data": {
    "message": {
      "id": "message_...",
      "role": "user",
      "content": [{"type": "text", "text": "Hello!"}],
      "created_at": "2024-01-15T10:30:00.000Z"
    }
  }
}

Output Events

output.message.started

Emitted when the LLM starts generating a response. This marks the start of generation, not model reasoning: reasoning has its own events (see Reasoning Events) and its own channel.

Field	Type	Description
turn_id	string	Turn ID this output belongs to
model	string?	Optional model name being used
phase	string?	Best-effort phase hint: commentary or final_answer. Absent means unclassified, never “reasoning”.

{
  "type": "output.message.started",
  "data": {
    "turn_id": "turn_...",
    "model": "gpt-4o"
  }
}

output.message.delta

Incremental text update during LLM generation. Events are batched (~100ms).

Field	Type	Description
turn_id	string	Turn ID this delta belongs to
delta	string	New text since last delta
accumulated	string	Total text so far

{
  "type": "output.message.delta",
  "data": {
    "turn_id": "turn_...",
    "delta": "Hello",
    "accumulated": "Hello"
  }
}

output.message.completed

Emitted when the agent response is complete.

Field	Type	Description
message	Message	The complete agent message
metadata	ModelMetadata?	Model information
usage	TokenUsage?	Token usage statistics

message.phase is authoritative for whether this message is intermediate commentary or the turn’s final_answer, and message.phase_source says whether the provider reported that phase (provider) or the runtime inferred it from tool-call presence (derived). Reasoning artifacts appear as reasoning content parts inside message.content, in the order the provider emitted them.

{
  "type": "output.message.completed",
  "data": {
    "message": {
      "id": "message_...",
      "role": "assistant",
      "content": [{"type": "text", "text": "Hello! How can I help?"}]
    },
    "usage": {
      "input_tokens": 50,
      "output_tokens": 25
    }
  }
}

Turn Lifecycle Events

turn.started

Emitted when a turn begins execution.

Field	Type	Description
turn_id	string	Turn identifier
input_message_id	string	Message that triggered this turn
input_content	string?	Optional input content preview

{
  "type": "turn.started",
  "data": {
    "turn_id": "turn_...",
    "input_message_id": "message_...",
    "input_content": "Hello!"
  }
}

turn.completed

Emitted when a turn completes successfully.

Field	Type	Description
turn_id	string	Turn identifier
iterations	integer	Number of reason-act iterations
duration_ms	integer?	Duration in milliseconds
usage	TokenUsage?	Aggregated token usage
input_content	string?	Optional input content
final_message_id	string?	Canonical final assistant message ID
final_answer_preview	string?	Bounded final answer preview
time_to_first_token_ms	integer?	First-token latency
tool_call_count	integer?	Completed tool-call count
llm_call_count	integer?	LLM generation count
status	string?	Optional completion status

{
  "type": "turn.completed",
  "data": {
    "turn_id": "turn_...",
    "iterations": 3,
    "duration_ms": 1500,
    "usage": {
      "input_tokens": 500,
      "output_tokens": 200
    },
    "final_message_id": "message_...",
    "final_answer_preview": "Done.",
    "time_to_first_token_ms": 120,
    "tool_call_count": 2,
    "llm_call_count": 3,
    "status": "completed"
  }
}

turn.failed

Emitted when a turn fails with an error.

Field	Type	Description
turn_id	string	Turn identifier
error	string	Error message
error_code	string?	Optional error code

{
  "type": "turn.failed",
  "data": {
    "turn_id": "turn_...",
    "error": "Rate limit exceeded",
    "error_code": "RATE_LIMIT"
  }
}

turn.cancelled

Emitted when a turn is cancelled by the user.

Field	Type	Description
turn_id	string	Turn identifier
reason	string?	Cancellation reason
usage	TokenUsage?	Usage before cancellation

{
  "type": "turn.cancelled",
  "data": {
    "turn_id": "turn_...",
    "reason": "User requested",
    "usage": {
      "input_tokens": 100,
      "output_tokens": 50
    }
  }
}

Reasoning Events

Model reasoning, as distinct from the reason.started / reason.completed lifecycle events further down, which mark an LLM inference step in the reason/act loop and are unrelated to whether the model reasoned.

These events are emitted by models that expose reasoning (Anthropic Claude with thinking enabled, OpenAI GPT-5.x and o-series with reasoning effort configured, Gemini with a thinking budget, and Chat Completions models that return reasoning_content). Everything here belongs to the reasoning channel and must never be rendered as assistant text.

reason.thinking.started

Emitted when extended thinking begins.

Field	Type	Description
turn_id	string	Turn ID
model	string?	Model name

{
  "type": "reason.thinking.started",
  "data": {
    "turn_id": "turn_...",
    "model": "claude-4-opus"
  }
}

reason.thinking.delta

Streams incremental thinking content.

Field	Type	Description
turn_id	string	Turn ID
delta	string	New thinking text
accumulated	string	Total thinking so far

{
  "type": "reason.thinking.delta",
  "data": {
    "turn_id": "turn_...",
    "delta": "Let me think about this...",
    "accumulated": "Let me think about this..."
  }
}

reason.thinking.completed

Emitted when extended thinking completes.

Field	Type	Description
turn_id	string	Turn ID
thinking	string	Complete thinking content

{
  "type": "reason.thinking.completed",
  "data": {
    "turn_id": "turn_...",
    "thinking": "I need to consider the user's request carefully..."
  }
}

reason.item

Emitted when one reasoning artifact completes. One event per provider reasoning block, in emission order.

Carries identity and safe summary text only. The opaque payloads that make the artifact replayable — provider signatures and encrypted reasoning context — are deliberately excluded: they are replay state, not content, and never appear in events or on any API surface.

Field	Type	Description
turn_id	string	Turn ID this artifact belongs to
provider	string	Provider that produced it (anthropic, openai, google)
model	string?	Model reported by the provider
item_id	string	Provider-assigned identifier, when the provider issues one
summary	string[]	Provider-curated summary segments. Never raw chain-of-thought.
token_count	integer?	Reasoning tokens attributed to this artifact

{
  "type": "reason.item",
  "data": {
    "turn_id": "turn_...",
    "provider": "openai",
    "model": "gpt-5.2",
    "item_id": "rs_68a1f...",
    "summary": ["Checking the build logs before answering."],
    "token_count": 412
  }
}

Atom Lifecycle Events

These events mark steps of the reason/act execution loop. reason.* here means “the LLM inference step”, not model reasoning — for that see Reasoning Events.

reason.started

Emitted when LLM inference begins.

Field	Type	Description
agent_id	string	Agent ID
metadata	ModelMetadata?	Model information

{
  "type": "reason.started",
  "data": {
    "agent_id": "agent_...",
    "metadata": {
      "model": "gpt-4o"
    }
  }
}

reason.completed

Emitted when LLM inference completes.

Field	Type	Description
success	boolean	Whether the call succeeded
text_preview	string?	First 200 chars of response
has_tool_calls	boolean	Whether tools were requested
tool_call_count	integer	Number of tool calls
error	string?	Error if failed
duration_ms	integer?	Duration
usage	TokenUsage?	Token usage

{
  "type": "reason.completed",
  "data": {
    "success": true,
    "text_preview": "Hello! I can help you with...",
    "has_tool_calls": false,
    "tool_call_count": 0,
    "duration_ms": 1200,
    "usage": {
      "input_tokens": 100,
      "output_tokens": 50
    }
  }
}

act.started

Emitted when tool execution batch begins.

Field	Type	Description
tool_calls	ToolCallSummary[]	Tools to be executed

{
  "type": "act.started",
  "data": {
    "tool_calls": [
      {"id": "tc_1", "name": "get_weather"},
      {"id": "tc_2", "name": "search_web"}
    ]
  }
}

act.completed

Emitted when tool execution batch completes.

Field	Type	Description
completed	boolean	All tools completed
success_count	integer	Successful tool calls
error_count	integer	Failed tool calls
duration_ms	integer?	Total duration

{
  "type": "act.completed",
  "data": {
    "completed": true,
    "success_count": 2,
    "error_count": 0,
    "duration_ms": 500
  }
}

tool.started

Emitted when individual tool execution begins.

Field	Type	Description
tool_call	ToolCall	Full tool call with arguments

{
  "type": "tool.started",
  "data": {
    "tool_call": {
      "id": "tc_1",
      "name": "get_weather",
      "arguments": {"city": "London"}
    }
  }
}

tool.completed

Emitted when individual tool execution completes.

Field	Type	Description
tool_call_id	string	Tool call ID
tool_name	string	Tool name
success	boolean	Whether it succeeded
status	string	“success”, “error”, “timeout”, “cancelled”
result	ContentPart[]?	Result content
error	string?	Error message
duration_ms	integer?	Duration

{
  "type": "tool.completed",
  "data": {
    "tool_call_id": "tc_1",
    "tool_name": "get_weather",
    "success": true,
    "status": "success",
    "result": [{"type": "text", "text": "Sunny, 22°C"}],
    "duration_ms": 250
  }
}

LLM Events

llm.generation

Full visibility into LLM API calls. Emitted after each call.

Field	Type	Description
messages	Message[]	Messages sent to LLM
tools	ToolDefinitionSummary[]	Available tools
output	LlmGenerationOutput	LLM response
metadata	LlmGenerationMetadata	Call metadata

{
  "type": "llm.generation",
  "data": {
    "messages": [...],
    "tools": [{"name": "get_weather", "description": "..."}],
    "output": {
      "text": "Hello!",
      "tool_calls": []
    },
    "metadata": {
      "model": "gpt-4o",
      "provider": "openai",
      "usage": {"input_tokens": 100, "output_tokens": 50},
      "duration_ms": 1200,
      "time_to_first_token_ms": 150,
      "success": true,
      "finish_reasons": ["stop"]
    }
  }
}

Session Events

session.started

Emitted when a session begins.

Field	Type	Description
agent_id	string	Agent ID
model_id	string?	Model ID if specified

{
  "type": "session.started",
  "data": {
    "agent_id": "agent_..."
  }
}

session.activated

Emitted when a session becomes active (turn started).

Field	Type	Description
turn_id	string	Turn that activated session
input_message_id	string	Triggering message

{
  "type": "session.activated",
  "data": {
    "turn_id": "turn_...",
    "input_message_id": "message_..."
  }
}

session.idled

Emitted when a session becomes idle (turn completed).

Field	Type	Description
turn_id	string	Completed turn
iterations	integer?	Iterations in turn
usage	TokenUsage?	Cumulative session usage

{
  "type": "session.idled",
  "data": {
    "turn_id": "turn_...",
    "iterations": 3,
    "usage": {
      "input_tokens": 1500,
      "output_tokens": 800
    }
  }
}

Subagent Events (retired)

The subagent.spawned, subagent.completed, subagent.failed, and subagent.cancelled events have been retired. The subagent flow is now modeled as Session Tasks, which emit task.* lifecycle events (task.created, task.updated, task.message.sent, task.message.received) on the parent session instead. New sessions never emit subagent.*.

These event types are no longer produced or part of the supported contract. Historical subagent.* events recorded in older session logs remain in storage, but are filtered out of the events and SSE APIs like any unsupported type, they are not returned to consumers (aggregate counters such as error_count still include them). Consumers should read task.* events going forward.

Supporting Types

TokenUsage

Token consumption statistics.

Field	Type	Description
input_tokens	integer	Input/prompt tokens
output_tokens	integer	Output/completion tokens
cache_read_tokens	integer?	Tokens read from cache
cache_creation_tokens	integer?	Tokens written to cache (Anthropic)

ModelMetadata

Information about the model used.

Field	Type	Description
model	string	Model name (e.g., “gpt-4o”)
model_id	string?	Internal model ID
provider_id	string?	Internal provider ID

ToolCallSummary

Compact tool call representation.

Field	Type	Description
id	string	Tool call ID
name	string	Tool name

ToolCall

Full tool call with arguments.

Field	Type	Description
id	string	Tool call ID
name	string	Tool name
arguments	object	Tool arguments (JSON)