POST /api/acl-templates/{id}/members

Add one member to an ACL template.

GET_ACL_TEMPLATE, FIND_PRINCIPAL when systemId is omitted, UPDATE_ACL_TEMPLATE with code 5 (ADD_ACLTEMPLATE_MEMBER), then GET_ACL_TEMPLATE to read back: saved is true only when the member reads back with exactly the requested rights.

A member must grant at least one of read and write; that is refused here, because the key server does not check it. The key server requires the caller to be a member of the template holding write; a caller who is not is answered 403 ACCESS_DENIED with the key server's own sentence.

Role: Security Officer; an Administrator on a split deployment receives 403.

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
id	path	yes	string	The ACL template id.

Request

Field	Type	Required	Description
principalId	string	yes
systemId	integer or null	no	Resolved from the principal when absent or null.
read	boolean	no
write	boolean	no

Example

{
  "principalId": "...",
  "systemId": 0,
  "read": true,
  "write": true
}

Responses

200

Added, and read back with the requested rights.

Field	Type	Required	Description
id	string	yes
saved	boolean	yes
missing	boolean	no
requested	object	no
template	object or null	no

requested object

Field	Type	Required	Description
principalId	string	no
systemId	integer	no
read	boolean	no
write	boolean	no

Example

{
  "id": "...",
  "saved": true,
  "missing": true,
  "requested": {
    "principalId": "...",
    "systemId": 0,
    "read": true,
    "write": true
  },
  "template": {}
}

400

BAD_REQUEST -- a malformed id or principalId, a systemId below 1, a non-boolean read/write, neither right granted, or a principal this key server does not hold.

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

ACCESS_DENIED -- the operation gate, or the key server's object-level refusal: the caller is not a write-holding member of this template. detail is the key server's sentence.

404

NOT_FOUND -- no ACL template has that id.

409

ALREADY_MEMBER -- the principal is already a member; change its rights with PUT. Or the add was accepted and the member does not read back with the requested rights: that body is the 200 shape with saved: false and the Gateway adds code: NOT_SAVED and a detail to it (compose.ts).

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 -- a malformed id or principalId, a systemId below 1, a non-boolean read/write, neither right granted, or a principal this key server does not hold.
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	ACCESS_DENIED -- the operation gate, or the key server's object-level refusal: the caller is not a write-holding member of this template. detail is the key server's sentence.
404	NOT_FOUND -- no ACL template has that id.
409	ALREADY_MEMBER -- the principal is already a member; change its rights with PUT. Or the add was accepted and the member does not read back with the requested rights: that body is the 200 shape with saved: false and the Gateway adds code: NOT_SAVED and a detail to it (compose.ts).
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.