`GET /api/groups/{gid}/members`

List a group's members.

Lists the members of the group named by {gid}.

An empty members list means the group has no members. It does not mean the group is missing. The key server answers an empty list for both cases and cannot tell them apart, so this route resolves the group id SEPARATELY first and answers 404 only when that read finds nothing -- or finds something that is not a group.

There is no POST /api/groups: a group IS a principal, so it is created at POST /api/principals with type: group and listed at GET /api/principals?type=group. Only membership lives here.

Every id is carried in both spellings, and the difference matters on the very next call: the hex id is what these path segments take, while principalId (decimal) plus systemId are what POST /api/keys/acl/grant takes to give this GROUP access to a key -- which is the usual reason to have made one.

Authentication

Send the session id as Authorization: Bearer <session id>, and an RFC 9449 DPoP proof in the DPoP header if your session is bound to a key. The two are required together, not as alternatives — see Authenticating and Proving you hold your key.

This surface sets no cookie

There is no session cookie on any response and none is read on any request. Do not set credentials: "include" on a browser fetch.

Parameters

Name	In	Required	Type	Description
`gid`	path	yes	`string`	A group's principal id as 16 hex digits (the `id` field, not `principalId`).

Request

No request body.

Responses

`200`

The group and its members.

Field	Type	Required	Description
`gid`	`string`	yes
`group`	`Principal`	yes	A principal, carrying its id in BOTH spellings because different routes take different ones. `id` (16 hex digits) is what this API's `{id}`, `{gid}` and `{pid}` path segments take; `principalId` (a decimal string of the same eight bytes) together with `systemId` is what the ACL and export routes take.
`count`	`integer`	yes
`members`	array of `Principal`	yes	A principal, carrying its id in BOTH spellings because different routes take different ones. `id` (16 hex digits) is what this API's `{id}`, `{gid}` and `{pid}` path segments take; `principalId` (a decimal string of the same eight bytes) together with `systemId` is what the ACL and export routes take.
`detail`	`string`	no

Principal

Field	Type	Required	Description
`id`	`string`	no	16 hex digits.
`principalId`	`string` or `null`	no	The same eight bytes as a decimal string. A string, so that an id above 2^53 survives.
`systemId`	`integer` or `null`	no	Assigned by the key server at setup. READ IT FROM THE SERVER; a hardcoded value addresses a principal that does not exist and yields a misleading "unknown principal".
`className`	`string` or `null`	no	The key server's own class name -- `UserAndPasswordInfo`, `TransportPrincipalInfo`, `LdapPrincipalInfo`, `XAuthPrincipalInfo` or `GroupInfo`.
`name`	`string` or `null`	no
`disabled`	`boolean` or `null`	no
`roleIds`	array of `string`	no
`groupIds`	array of `string`	no

Example

{
  "gid": "...",
  "group": {
    "id": "...",
    "principalId": "...",
    "systemId": 0,
    "className": "...",
    "name": "...",
    "disabled": true,
    "roleIds": [
      "..."
    ],
    "groupIds": [
      "..."
    ]
  },
  "count": 0,
  "members": [
    {
      "id": "...",
      "principalId": "...",
      "systemId": 0,
      "className": "...",
      "name": "...",
      "disabled": true,
      "roleIds": [
        "..."
      ],
      "groupIds": [
        "..."
      ]
    }
  ],
  "detail": "..."
}

`400`

BAD_REQUEST -- gid is not 16 hex digits.

`401`

No live session, a DPoP proof that did not verify, or a certificate session whose certificate the key server now refuses.

SESSION_NOT_FOUND -- the credential names no session this Gateway holds. SESSION_EXPIRED -- it aged out. Both carry reauth: true; obtain a new credential rather than retrying.

PROOF_* -- the sender constraint refused. See the DPoP section of this document for the full table; PROOF_MALFORMED is a 400 and PROOF_REPLAY_CACHE_FULL a 503, and the rest are here.

SCOPED_CREDENTIAL_EXPIRED -- a scoped browser credential passed its fixed lifetime. Use does not extend it: an idle timeout would be refreshed by exactly the traffic a stolen handle produces.

CERTIFICATE_REVOKED -- on a session established by certificate login, the key server re-checks the certificate that session was established with on its operations, and it is now named by revocation evidence (ADR 0115). detail is the key server's sentence. Every later operation of the session is refused the same way; log in with a different certificate.

`403`

Authenticated, and refused. The codes differ in what they say about where the refusal came from: ACCESS_DENIED, PRINCIPAL_DISABLED and DELEGATOR_REFUSED are the key server's -- the last one on a DELEGATED session whose delegator has since been disabled, lost its DELEGATION flag, been unenrolled or had its certificate revoked (ADR-0123); its detail is the key server's sentence naming the delegator, and no new login helps until an administrator restores it. REVOCATION_STATUS_UNAVAILABLE and REVOCATION_EVIDENCE_STALE are the key server's too, on a session established by certificate login: the same re-check found no current revocation evidence for that certificate's issuer under a policy that requires it (ADR 0115) -- the credential is not what was refused, and an operator importing a current CRL for the issuer is what helps -- while NOT_WRITABLE, BUILT_IN_PRINCIPAL, OWN_ACCOUNT and OBJECT_NOT_IN_CREDENTIAL_SCOPE are decided by the Gateway before anything is sent.

`404`

NO_GROUP -- no principal with that id. NOT_A_GROUP -- a principal with that id exists and is not a group; it is refused rather than read, because reading it would have answered an empty list that a caller would reasonably take for "this group is empty".

`500`

A fault rather than a refusal.

OP_FAILED is the catch-all: the key server refused in words that match no classified pattern, so the Gateway cannot say more than that the operation did not happen. Some key server refusals that are conceptually a caller error arrive here rather than as a 4xx, because the wire carries no distinguishing code -- where a route can recognise one from its message it maps it, and each such mapping is documented on the operation.

`503`

A capacity ceiling or a missing deployment prerequisite. retryable says which.

A scope of session or process names the ceiling that was hit, and the response carries Retry-After.

BUILD_NOT_ADMITTED (scope: process, retryable: true, Retry-After): the key server does not admit this Gateway's client build. Every key-server connection the Gateway opens attests the signed release it runs (TE_RELEASE_MANIFEST) right after it authenticates; while that attestation is refused -- the release is not registered at the key server's code-signing level, the level was raised under it, or the installed files no longer match the signed manifest -- every route but GET /api/health and GET /api/ready answers this, and detail names the cause. It is never a 401 or a 403: no credential or role of the caller's is at fault. The Gateway re-attempts on a timer and recovers without a restart once the key server admits it; GET /api/ready says when.

Error handling

Every failure answers JSON carrying at least code and detail. Match on code — detail is written for a human debugging the call and its wording is not part of the contract. See the error model.

Status	Meaning
`400`	`BAD_REQUEST` -- `gid` is not 16 hex digits.
`401`	No live session, a DPoP proof that did not verify, or a certificate session whose certificate the key server now refuses. `SESSION_NOT_FOUND` -- the credential names no session this Gateway holds. `SESSION_EXPIRED` -- it aged out. Both carry `reauth: true`; obtain a new credential rather than retrying. `PROOF_*` -- the sender constraint refused. See the DPoP section of this document for the full table; `PROOF_MALFORMED` is a `400` and `PROOF_REPLAY_CACHE_FULL` a `503`, and the rest are here. `SCOPED_CREDENTIAL_EXPIRED` -- a scoped browser credential passed its fixed lifetime. Use does not extend it: an idle timeout would be refreshed by exactly the traffic a stolen handle produces. `CERTIFICATE_REVOKED` -- on a session established by certificate login, the key server re-checks the certificate that session was established with on its operations, and it is now named by revocation evidence (ADR 0115). `detail` is the key server's sentence. Every later operation of the session is refused the same way; log in with a different certificate.
`403`	Authenticated, and refused. The codes differ in what they say about where the refusal came from: `ACCESS_DENIED`, `PRINCIPAL_DISABLED` and `DELEGATOR_REFUSED` are the key server's -- the last one on a DELEGATED session whose delegator has since been disabled, lost its DELEGATION flag, been unenrolled or had its certificate revoked (ADR-0123); its `detail` is the key server's sentence naming the delegator, and no new login helps until an administrator restores it. `REVOCATION_STATUS_UNAVAILABLE` and `REVOCATION_EVIDENCE_STALE` are the key server's too, on a session established by certificate login: the same re-check found no current revocation evidence for that certificate's issuer under a policy that requires it (ADR 0115) -- the credential is not what was refused, and an operator importing a current CRL for the issuer is what helps -- while `NOT_WRITABLE`, `BUILT_IN_PRINCIPAL`, `OWN_ACCOUNT` and `OBJECT_NOT_IN_CREDENTIAL_SCOPE` are decided by the Gateway before anything is sent.
`404`	`NO_GROUP` -- no principal with that id. `NOT_A_GROUP` -- a principal with that id exists and is not a group; it is refused rather than read, because reading it would have answered an empty list that a caller would reasonably take for "this group is empty".
`500`	A fault rather than a refusal. `OP_FAILED` is the catch-all: the key server refused in words that match no classified pattern, so the Gateway cannot say more than that the operation did not happen. Some key server refusals that are conceptually a caller error arrive here rather than as a `4xx`, because the wire carries no distinguishing code -- where a route can recognise one from its message it maps it, and each such mapping is documented on the operation.
`503`	A capacity ceiling or a missing deployment prerequisite. `retryable` says which. A `scope` of `session` or `process` names the ceiling that was hit, and the response carries `Retry-After`. `BUILD_NOT_ADMITTED` (`scope: process`, `retryable: true`, `Retry-After`): the key server does not admit this Gateway's client build. Every key-server connection the Gateway opens attests the signed release it runs (`TE_RELEASE_MANIFEST`) right after it authenticates; while that attestation is refused -- the release is not registered at the key server's code-signing level, the level was raised under it, or the installed files no longer match the signed manifest -- every route but `GET /api/health` and `GET /api/ready` answers this, and `detail` names the cause. It is never a `401` or a `403`: no credential or role of the caller's is at fault. The Gateway re-attempts on a timer and recovers without a restart once the key server admits it; `GET /api/ready` says when.

Authentication​

Parameters​

Request​

Responses​

200​

400​

401​

403​

404​

500​

503​

Error handling​