step.log

One tool call or reasoning step, for the receipt and the run timeline.

Direction: Harness → Chips
Sent by: a harness
Requires a run: yes
Schema: step.log.json

Fields

Every event also carries the envelope.

Field	Required	Type	Description
v	yes	1	Protocol major version.
type	yes	"step.log"
id	yes	string	The event’s own id. Stable across a retry of the same event.
ts	yes	string	When it happened, by Chips’ clock. Stamped on the way in; a value the sender writes is replaced.
workspace_id	yes	string	A workspace identifier: ws_ followed by a ULID.
space_id	no	string	The space, when the event belongs to one.
run_id	no	string	The run, when the event belongs to one.
seq	no	number	Assigned by the server on append, monotonic per workspace. Absent on the way in.
idempotency_key	no	string	Required on every client-originated write. Sending the same key twice is a no-op.
actor	yes	object	The participant an event is attributed to.
actor.kind	yes	"person" | "harness" | "agent" | "system"	Whether a person, a harness, one of a harness’s agents or Chips itself acted.
actor.id	yes	string	The participant id, or system for Chips.
actor.harness_id	no	string	For an agent: the harness it speaks through, whose budget and runs are the agent’s (ADR 0087). Filled in by Chips.
step_id	yes	string	Stable across the started and done events for one step.
status	yes	"started" | "done" | "failed"	Where this step got to.
title	no	string	What the step is, when it was not in the plan.
tool	no	string	The tool called, for example drive.read.
kind	no	enum	What kind of call the tool is, when the harness knows: the apps draw a step by it where they do not know the tool by its name. One of search, web, shell, image, memory, edit, file, mail, handoff, other.
summary	no	string	One line for the receipt.
sources	no	object[]	Where the information came from.
sources[].kind	yes	"external" | "internal"	Whether the source is outside the workspace.
sources[].label	yes	string	What to show in the receipt, for example vendor website.
sources[].url	no	string	Where to look, when there is somewhere to look.
duration_ms	no	number	How long the step took.
error	no	string	Why it failed, when it did.

Example

{
  "v": 1,
  "type": "step.log",
  "id": "evt_01K4ZQPX000000000000000066",
  "ts": "2026-09-02T14:22:02.004Z",
  "workspace_id": "ws_01K4ZQPX000000000000000001",
  "space_id": "spc_01K4ZQPX000000000000000002",
  "actor": {
    "kind": "harness",
    "id": "hrn_01K4ZQPX000000000000000004"
  },
  "run_id": "run_01K4ZQPX000000000000000005",
  "step_id": "read-po",
  "status": "done",
  "title": "Read PO #4471",
  "tool": "drive.read",
  "summary": "120 units, delivery 19 September, signed by Arjun.",
  "sources": [
    {
      "kind": "internal",
      "label": "Drive",
      "url": "https://drive.example/po-4471"
    }
  ],
  "duration_ms": 1840
}