Skip to content

Replace canonical app host selection at an expected revision.

PATCH
/v1/admin/apps/{id}/placement
curl --request PATCH \
--url http://localhost:8080/v1/admin/apps/2489E9AD-2EE2-8E00-8EC9-32D5F69181C0/placement \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '{ "expected_revision": "example", "mode": "all_eligible", "host_ids": [ "2489E9AD-2EE2-8E00-8EC9-32D5F69181C0" ] }'

Invalid selection is 400 validation_failed. A stale revision is 409 stale_revision with the current placement. A derived tile is 409 inherited_placement with its parent ID. Removal immediately excludes new reservations while existing sessions finish and homes/images stay.

id
required
string format: uuid
Media typeapplication/json
object
expected_revision
required

Canonical nonnegative decimal string; no sign, whitespace or leading zeros.

string
/^(0|[1-9][0-9]*)$/
mode
required
string
Allowed values: all_eligible fixed
host_ids
required

Must be empty for all_eligible.

Array<string>
unique items

Updated placement.

Media typeapplication/json
object
app_id
required

Canonical parent app ID.

string format: uuid
inherited_from
required

Canonical parent ID for a derived tile; null on the parent itself.

string | null format: uuid
mode
required
string
Allowed values: all_eligible fixed
host_ids
required

Fixed selection; empty is valid and allows no host.

Array<string>
unique items
revision
required

Canonical nonnegative decimal string; no sign, whitespace or leading zeros.

string
/^(0|[1-9][0-9]*)$/
managed_image_id
required

RH05 #343. Catalog ID matched to the canonical app’s effective image (runtime_spec.image, else linked preset image) using the immutable adopted registry ref or local tag; null for an unmanaged or image-free app. Independent of the catalog’s current upstream digest and preparation status.

string | null
hosts
required

Selection, preparation and readiness are distinct per-host observations.

Array<object>
object
host_id
required
string format: uuid
selected
required
boolean
prepared
required

Null when preparation evidence is unknown.

boolean | null
ready
required

Null when readiness evidence is unknown.

boolean | null
reason

Safe open code: unmanaged_image, no_image, on_demand, not_required, awaiting_preparation, preparing, preparation_failed, inventory_unknown, removing (after 0094); unknown future codes render generically. Prepared on an unselected host is observation only.

string | null
Example
{
"mode": "all_eligible"
}

Malformed or invalid request.

Media typeapplication/json
object
error
required
object
code
required

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, host_not_ready, restart_required, stale_revision, unsupported_source, approval_superseded, approval_expired, attempt_conflict, cancel_too_late, retry_exhausted, home_conflict, placement_ineligible, inherited_placement, recovery_uncertain, 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.

string
message
required
string
live_sessions

Present on restart_required.

integer
session_id

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. Also omitted when the holder is the caller’s parked session or released runtime (amendment 39). 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.

string format: uuid
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.

Array<object>
object
id
required
string format: uuid
name
required
string
reason

Amendment 40 (#602), ADDITIVE: a machine-readable cause under code. On 503 no_host_available, home_host_unavailable: the launch is pinned to the host that holds the caller’s home for this app (Amendment 53: or it is pinned to the host of the caller’s Steam home for a sharing launch) and that host is offline or no longer enrolled. Only an admin clears it, so a client does not spend its automatic retry on it. Names no host. Amendment 53 (#1001), on 409 home_in_use: steam_library_open_in_desktop (the holder mounts the Steam library as a shared home) or steam_game_running (the refused launch shares the library and a Steam session holds it); absent when the holder is already stopping. Open string: a client treats an unknown value as absent.

string
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"
}
],
"reason": "example"
}
}

Missing/invalid/expired/revoked token.

Media typeapplication/json
object
error
required
object
code
required

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, host_not_ready, restart_required, stale_revision, unsupported_source, approval_superseded, approval_expired, attempt_conflict, cancel_too_late, retry_exhausted, home_conflict, placement_ineligible, inherited_placement, recovery_uncertain, 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.

string
message
required
string
live_sessions

Present on restart_required.

integer
session_id

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. Also omitted when the holder is the caller’s parked session or released runtime (amendment 39). 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.

string format: uuid
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.

Array<object>
object
id
required
string format: uuid
name
required
string
reason

Amendment 40 (#602), ADDITIVE: a machine-readable cause under code. On 503 no_host_available, home_host_unavailable: the launch is pinned to the host that holds the caller’s home for this app (Amendment 53: or it is pinned to the host of the caller’s Steam home for a sharing launch) and that host is offline or no longer enrolled. Only an admin clears it, so a client does not spend its automatic retry on it. Names no host. Amendment 53 (#1001), on 409 home_in_use: steam_library_open_in_desktop (the holder mounts the Steam library as a shared home) or steam_game_running (the refused launch shares the library and a Steam session holds it); absent when the holder is already stopping. Open string: a client treats an unknown value as absent.

string
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"
}
],
"reason": "example"
}
}

Authenticated but insufficient role / not the owner (precedes resource lookup).

Media typeapplication/json
object
error
required
object
code
required

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, host_not_ready, restart_required, stale_revision, unsupported_source, approval_superseded, approval_expired, attempt_conflict, cancel_too_late, retry_exhausted, home_conflict, placement_ineligible, inherited_placement, recovery_uncertain, 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.

string
message
required
string
live_sessions

Present on restart_required.

integer
session_id

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. Also omitted when the holder is the caller’s parked session or released runtime (amendment 39). 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.

string format: uuid
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.

Array<object>
object
id
required
string format: uuid
name
required
string
reason

Amendment 40 (#602), ADDITIVE: a machine-readable cause under code. On 503 no_host_available, home_host_unavailable: the launch is pinned to the host that holds the caller’s home for this app (Amendment 53: or it is pinned to the host of the caller’s Steam home for a sharing launch) and that host is offline or no longer enrolled. Only an admin clears it, so a client does not spend its automatic retry on it. Names no host. Amendment 53 (#1001), on 409 home_in_use: steam_library_open_in_desktop (the holder mounts the Steam library as a shared home) or steam_game_running (the refused launch shares the library and a Steam session holds it); absent when the holder is already stopping. Open string: a client treats an unknown value as absent.

string
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"
}
],
"reason": "example"
}
}

No such resource.

Media typeapplication/json
object
error
required
object
code
required

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, host_not_ready, restart_required, stale_revision, unsupported_source, approval_superseded, approval_expired, attempt_conflict, cancel_too_late, retry_exhausted, home_conflict, placement_ineligible, inherited_placement, recovery_uncertain, 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.

string
message
required
string
live_sessions

Present on restart_required.

integer
session_id

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. Also omitted when the holder is the caller’s parked session or released runtime (amendment 39). 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.

string format: uuid
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.

Array<object>
object
id
required
string format: uuid
name
required
string
reason

Amendment 40 (#602), ADDITIVE: a machine-readable cause under code. On 503 no_host_available, home_host_unavailable: the launch is pinned to the host that holds the caller’s home for this app (Amendment 53: or it is pinned to the host of the caller’s Steam home for a sharing launch) and that host is offline or no longer enrolled. Only an admin clears it, so a client does not spend its automatic retry on it. Names no host. Amendment 53 (#1001), on 409 home_in_use: steam_library_open_in_desktop (the holder mounts the Steam library as a shared home) or steam_game_running (the refused launch shares the library and a Steam session holds it); absent when the holder is already stopping. Open string: a client treats an unknown value as absent.

string
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"
}
],
"reason": "example"
}
}

Stale revision or inherited placement.

Media typeapplication/json
object
error
required
object
code
required

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, host_not_ready, restart_required, stale_revision, unsupported_source, approval_superseded, approval_expired, attempt_conflict, cancel_too_late, retry_exhausted, home_conflict, placement_ineligible, inherited_placement, recovery_uncertain, 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.

string
message
required
string
live_sessions

Present on restart_required.

integer
session_id

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. Also omitted when the holder is the caller’s parked session or released runtime (amendment 39). 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.

string format: uuid
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.

Array<object>
object
id
required
string format: uuid
name
required
string
reason

Amendment 40 (#602), ADDITIVE: a machine-readable cause under code. On 503 no_host_available, home_host_unavailable: the launch is pinned to the host that holds the caller’s home for this app (Amendment 53: or it is pinned to the host of the caller’s Steam home for a sharing launch) and that host is offline or no longer enrolled. Only an admin clears it, so a client does not spend its automatic retry on it. Names no host. Amendment 53 (#1001), on 409 home_in_use: steam_library_open_in_desktop (the holder mounts the Steam library as a shared home) or steam_game_running (the refused launch shares the library and a Steam session holds it); absent when the holder is already stopping. Open string: a client treats an unknown value as absent.

string
current
object
app_id
required

Canonical parent app ID.

string format: uuid
inherited_from
required

Canonical parent ID for a derived tile; null on the parent itself.

string | null format: uuid
mode
required
string
Allowed values: all_eligible fixed
host_ids
required

Fixed selection; empty is valid and allows no host.

Array<string>
unique items
revision
required

Canonical nonnegative decimal string; no sign, whitespace or leading zeros.

string
/^(0|[1-9][0-9]*)$/
managed_image_id
required

RH05 #343. Catalog ID matched to the canonical app’s effective image (runtime_spec.image, else linked preset image) using the immutable adopted registry ref or local tag; null for an unmanaged or image-free app. Independent of the catalog’s current upstream digest and preparation status.

string | null
hosts
required

Selection, preparation and readiness are distinct per-host observations.

Array<object>
object
host_id
required
string format: uuid
selected
required
boolean
prepared
required

Null when preparation evidence is unknown.

boolean | null
ready
required

Null when readiness evidence is unknown.

boolean | null
reason

Safe open code: unmanaged_image, no_image, on_demand, not_required, awaiting_preparation, preparing, preparation_failed, inventory_unknown, removing (after 0094); unknown future codes render generically. Prepared on an unselected host is observation only.

string | null
changed_host_ids
Array<string>
parent_app_id

Present on inherited_placement.

string format: uuid
Example
{
"current": {
"mode": "all_eligible"
}
}