agent.attached

An agent was put in a room: added, moved in, or brought back. Its harness is handed the room’s last lines with it.

Direction: Chips → the log
Sent by: Chips only; refused from a client
Requires a run: no
Schema: agent.attached.json

Fields

Every event also carries the envelope.

Field	Required	Type	Description
v	yes	1	Protocol major version.
type	yes	"agent.attached"
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.
agent_id	yes	string	The agent, in the room this event’s space_id names.
by	no	string	Who put it there: a person, its harness, or Chips (system).
moved_from	no	string	The room it left for this one, when moved.
fork_of	no	string	The agent.fork this copy answers, when it is a fork’s copy (ADR 0087, Fork).
made_for	no	string	The agent.asked this new agent answers, when a person asked for it (ADR 0108).
catch_up	no	object	The room’s last lines before the agent joined, within the budget its harness gave in hello (ADR 0088, point 5). Added as it is sent to the harness; the log does not keep it.
catch_up.lines	yes	object[]	Oldest first, the newest that fit the budget.
catch_up.lines[].seq	yes	number	Where in the log it happened.
catch_up.lines[].at	yes	string	When.
catch_up.lines[].kind	yes	"said" | "joined" | "left" | "renamed" | "archived" | "unarchived"	said: a message, addressed to this harness or not. joined and left: somebody came into the room or went. renamed: somebody took a new name, or the room a new title. archived and unarchived: the room was put away or brought back.
catch_up.lines[].from	yes	object	Who: the one who said it, came, went or took the new name; for the room’s own lines, who retitled, archived or unarchived it.
catch_up.lines[].from.id	yes	string	Their participant id, or system.
catch_up.lines[].from.kind	yes	"person" | "harness" | "agent" | "system"
catch_up.lines[].from.name	yes	string	What they go by now.
catch_up.lines[].from.role	no	"owner" | "member" | "guest"	Their standing in this room, when they are in it (SEC-15).
catch_up.lines[].from.workspace_role	no	"owner" | "admin" | "member" | "guest"	A person’s standing in the workspace (SEC-15): the plain form says it after the name, so a guest’s line reads as a guest’s. Absent for an agent or a harness.
catch_up.lines[].message_id	no	string	On said: the message.
catch_up.lines[].text	no	string	On said: the words as they read now, so an edited message reads edited; a deleted one is not a line. Cut with an ellipsis when the one line is longer than the whole budget.
catch_up.lines[].transcript	no	string	On said: what a voice note said, as the server heard it (ADR 0054).
catch_up.lines[].files	no	string[]	On said: the names of the files it carried.
catch_up.lines[].addressed_to	no	string[]	On said: the agents it was for (ADR 0081, ADR 0087), so a harness can leave out a line one of its agents already took a turn on. Absent on a message from before Chips said so.
catch_up.lines[].held	no	true	On said: the guard held it (ADR 0081), so it was for nobody.
catch_up.lines[].name	no	string	On renamed, for a participant: the name they took.
catch_up.lines[].previous	no	string	On renamed, for a participant: the name they went by until then.
catch_up.lines[].title	no	string	On renamed, for the room: its new title.
catch_up.since_seq	yes	number	Where they start: after this seq. With a message, where the turn that said the harness’s own last message in the room began (ADR 0105), else its joining; from the pull route, 0.
catch_up.truncated	yes	boolean	Whether older lines after since_seq were left out to fit the budget.
catch_up.before	yes	number	A cursor: GET /v1/spaces/:id/context?before= this reads what came before these lines.
catch_up.files	no	object[]	The room’s files at their current version, newest first, the 20 newest (ADR 0099): with a message, as of it, its own files included; from the pull route, as of now. Each with a URL for this harness. Absent from a Chips before files, and when the room has none.
catch_up.files[].name	yes	string	The file’s name, which its versions share.
catch_up.files[].version	yes	number	Which version this is: 1 for the first, counting each change of its bytes.
catch_up.files[].attachment_id	yes	string	The attachment that is this version: what a post names in replaces when it changes it.
catch_up.files[].sha256	yes	string	Lowercase hex digest of this version’s bytes.
catch_up.files[].byte_size	yes	number	Size in bytes.
catch_up.files[].mime_type	yes	string	Sniffed from the bytes on upload.
catch_up.files[].by	yes	object	Who posted this version, as a line’s from says it.
catch_up.files[].by.id	yes	string	Their participant id.
catch_up.files[].by.kind	yes	"person" | "harness" | "agent" | "system"
catch_up.files[].by.name	yes	string	What they go by now.
catch_up.files[].at	yes	string	When this version was posted.
catch_up.files[].message_id	no	string	The message that posted this version.
catch_up.files[].width	no	number	Pixels, for a photo or a video.
catch_up.files[].height	no	number	Pixels, for a photo or a video.
catch_up.files[].duration_ms	no	number	Milliseconds, for a sound or a video.
catch_up.files[].replaces	no	string	In one name’s versions (?name=): the version this one was made from, as its post said (message.post.replaces). Absent where the post said nothing, or named no version of this file.
catch_up.files[].url	no	string	For a harness: a signed URL for this version, bound to its token, as a message’s attachments are. Absent for a person, who fetches it by id.
catch_up.files[].url_expires_at	no	string	When url stops working.
catch_up.spend	no	object	What the room’s job has spent, as of the message (for one Chips held, as of its hand-over, when a new job began), against what the room allows a job (ADR 0117). With a message only; the room note says it in words. Absent from a Chips before it.
catch_up.spend.ceiling_usd	yes	number	What the room allows a job, in US dollars: its own ceiling, or the default (3) when nobody has set one.
catch_up.spend.spent_usd	yes	number	What the room’s runs reported costing since the job began, in US dollars, every harness’s together.
catch_up.spend.since_seq	yes	number	Where the job began: the seq of the last thing a person did in the room, or of the last brief handed into it, whichever is later; 0 when neither has happened.
catch_up.spend.uncounted_runs	yes	number	How many of the job’s runs reported no cost, and so count nothing.

Example

{
  "v": 1,
  "type": "agent.attached",
  "id": "evt_01K4ZQPX0000000000000000G3",
  "ts": "2026-09-30T09:06:00.004Z",
  "workspace_id": "ws_01K4ZQPX000000000000000001",
  "actor": {
    "kind": "person",
    "id": "usr_01K4ZQPX000000000000000003"
  },
  "agent_id": "agt_01K4ZQPX0000000000000000A1",
  "space_id": "spc_01K4ZQPX000000000000000002",
  "by": "usr_01K4ZQPX000000000000000003",
  "moved_from": "spc_01K4ZQPX0000000000000000S7"
}