Arm one bounded, on-demand observation of a live session.
const url = 'http://localhost:8080/v1/admin/sessions/2489E9AD-2EE2-8E00-8EC9-32D5F69181C0/capture';const options = { method: 'POST', headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'}, body: '{"kind":"pipeline_dot","params":{"windows":1,"window_ms":1}}'};
try { const response = await fetch(url, options); const data = await response.json(); console.log(data);} catch (error) { console.error(error);}use serde_json::json;use reqwest;
#[tokio::main]pub async fn main() { let url = "http://localhost:8080/v1/admin/sessions/2489E9AD-2EE2-8E00-8EC9-32D5F69181C0/capture";
let payload = json!({ "kind": "pipeline_dot", "params": json!({ "windows": 1, "window_ms": 1 }) });
let mut headers = reqwest::header::HeaderMap::new(); headers.insert("Authorization", "Bearer <token>".parse().unwrap()); headers.insert("Content-Type", "application/json".parse().unwrap());
let client = reqwest::Client::new(); let response = client.post(url) .headers(headers) .json(&payload) .send() .await;
let results = response.unwrap() .json::<serde_json::Value>() .await .unwrap();
dbg!(results);}curl --request POST \ --url http://localhost:8080/v1/admin/sessions/2489E9AD-2EE2-8E00-8EC9-32D5F69181C0/capture \ --header 'Authorization: Bearer <token>' \ --header 'Content-Type: application/json' \ --data '{ "kind": "pipeline_dot", "params": { "windows": 1, "window_ms": 1 } }'Session-capture. Observability only; arming a capture never changes a session. 202 means ARMED, not done — poll GET …/captures/{capture_id} for the result.
Authorizations
Section titled “Authorizations”Parameters
Section titled “Parameters”Path Parameters
Section titled “Path Parameters”Request Bodyrequired
Section titled “Request Bodyrequired”POST /v1/admin/sessions/{id}/capture body (session-capture).
object
The control plane owns this vocabulary and grows it; the enum is today’s set, not a closed world.
Burst_stats only; ignored by the other kinds. Clamped by the control plane and again by the agent.
object
Responses
Section titled “Responses”Armed; the agent acked.
202 body: the capture is ARMED. The capture_id is minted before dispatch, so the caller holds the join key immediately.
object
Examplegenerated
{ "capture_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "kind": "example", "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "accepted_at": "2026-04-15T12:00:00Z"}Missing/invalid/expired/revoked token.
object
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "error": { "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ] }}Authenticated but insufficient role / not the owner (precedes resource lookup).
object
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "error": { "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ] }}No such resource.
object
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "error": { "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ] }}Capture_busy (one in flight) or session_not_running.
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ]}Capture_kind_unsupported — the agent does not know this kind, or cannot do it now.
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ]}Capture_unsupported — this host’s agent predates captures. Rebuild it; retrying will not help.
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ]}Agent_not_connected — the session’s host has no live agent connection.
object
E.g. validation_failed, unauthorized, forbidden, not_found, conflict, session_quota_exceeded, home_in_use, home_not_provisioned, parent_app_disabled, profile_ineligible, profile_not_launchable_for_app, no_host_available, capacity_exhausted, restart_required, rate_limited, internal. Open string, not an enum: new codes are additive and an unknown one falls through to a client’s generic per-status branch.
Present on restart_required.
Steam library discovery Phase 3, ADDITIVE: present on home_in_use when the guard could name the CONFLICTING live session - the one already holding the home. It is here so the client can offer “go to your running session” with a link instead of a dead-end toast. OMITTED rather than empty when the conflict is known but the session is not, so a client branches on presence and never renders a link to nowhere. Load-bearing once derived tiles exist: the lock is held by the PARENT’s home, so a user who clicks a game tile can be refused because a DIFFERENT app (the Steam launcher, or another game from the same install) is running, and without the session id the refusal reads as a bug. See control-api.md §Derived tiles.
Steam library discovery Phase 3, ADDITIVE: present on the 409 conflict from DELETE /v1/apps/{id} when the app has derived tiles and ?delete_derived=true was not sent. A LIST, not a count - the point of the confirmation is that the admin sees what they are about to destroy. Capped; an empty array means the tiles could not be listed, never that there are none.
object
Examplegenerated
{ "code": "example", "message": "example", "live_sessions": 1, "session_id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "derived_tiles": [ { "id": "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0", "name": "example" } ]}