---
title: Get Root Certificates
description: Trusted CA (or 'root') certificates previously loaded into the
  Couchbase-Server cluster can be retrieved and inspected.
pubDate: 2026-08-17T09:53:44.266Z
antora:
  editUrl: https://github.com/couchbase/docs-server/edit/release/8.0/modules/rest-api/pages/get-trusted-cas.adoc
  xref: xref:server:rest-api:get-trusted-cas.adoc[]
---

[Consult the llms.txt file for a full list of contents](/llms.txt)
[View original HTML](/server/current/rest-api/get-trusted-cas.html)

# Get Root Certificates

> Trusted CA (or 'root') certificates previously loaded into the Couchbase-Server cluster can be retrieved and inspected. 

## [](#http-method-and-uri)HTTP Method and URI

GET /pools/default/trustedCAs

## [](#description)Description

Returns a JSON array, each of whose members is an object whose key-value pairs provide information on a CA certificate that has been and remains loaded for the cluster. Note that this list is therefore _complete_ and _cluster-wide_.

Note that although support of multiple root certificates is only available in versions of Couchbase Server that are 7.1 and later, this API _can_ be used on clusters that are running different versions of Couchbase Server, some of which are prior to 7.1.

## [](#curl-syntax)Curl Syntax

The curl syntax is as follows:

curl -X GET http://<ip-address-or-domain-name>:8091/pools/default/trustedCAs
 -u <username>:<password>

## [](#required-privileges)Required Privileges

Any user can call this method and endpoint. However, they will only see a redacted version which does not include cluster-private details. See the examples [Output Redaction](#output-redaction) to see what is omitted.

To see all details of the returned objects, the user must have one of the following roles:

* [Full Admin](../learn/security/roles.md#full-admin)
* [Security Admin](../learn/security/roles.md#security-admin)
* [Read-Only Security Admin](../learn/security/roles.md#ro-security-admin)

## [](#responses)Responses

Success returns `200 OK` and a JSON array, each of whose members is an object whose key-value pairs provide information on a trusted CA certificate that has been loaded on the cluster. If no trusted CA certificates have been loaded, the returned array is empty.

Failure to authenticate returns `HTTP/1.1 401 Unauthorized`.

A malformed URI returns `HTTP/1.1 404 Object Not Found`. An incorrect method returns `HTTP/1.1 405 Method Not Allowed`.

## [](#example)Example

The following example returns a list of all trusted CA certificates that are currently loaded on the cluster.

curl -X GET http://10.144.220.101:8091/pools/default/trustedCAs -u Administrator:password

Formatted, the output appears as follows:

[
  {
    "warnings": [
      {
        "name": "self_signed",
        "message": "Out-of-the-box certificates are self-signed. To further secure your system, you must create new X.509 certificates signed by a trusted CA.",
        "severity": 2,
        "severityName": "minimal"
      }
    ],
    "id": 0,
    "subject": "CN=Couchbase Server 90c7ba5e",
    "notBefore": "2013-01-01T00:00:00.000Z",
    "notAfter": "2049-12-31T23:59:59.000Z",
    "type": "generated",
    "pem": "-----BEGIN CERTIFICATE-----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\nZPLSLJZ2\n-----END CERTIFICATE-----\n\n",
    "nodes": [
      "10.144.220.101:8091",
      "10.144.220.102:8091"
    ]
  },
  {
    "warnings": [],
    "id": 2,
    "loadTimestamp": "2021-11-23T12:36:37.000Z",
    "subject": "CN=Couchbase Root CA",
    "notBefore": "2021-11-22T16:37:47.000Z",
    "notAfter": "2031-11-20T16:37:47.000Z",
    "type": "uploaded",
    "pem": "-----BEGIN CERTIFICATE-----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\nRDy/b+3vQ/g1+iwfq+m6m0pZHIzilIoHM8jMzjI=\n-----END CERTIFICATE-----\n\n",
    "loadHost": "10.144.220.101",
    "loadFile": "/opt/couchbase/var/lib/couchbase/inbox/CA/ca.pem",
    "nodes": []
  },
  {
    "warnings": [],
    "id": 3,
    "loadTimestamp": "2021-11-23T12:42:27.000Z",
    "subject": "CN=Couchbase Root CA2",
    "notBefore": "2021-11-23T12:34:51.000Z",
    "notAfter": "2031-11-21T12:34:51.000Z",
    "type": "uploaded",
    "pem": "-----BEGIN CERTIFICATE-----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\nuwR6xdz/1EnMqLRfcXDMBsxSMp4vdiA+46NSj3U89g==\n-----END CERTIFICATE-----\n\n",
    "loadHost": "10.144.220.101",
    "loadFile": "/opt/couchbase/var/lib/couchbase/inbox/CA/ca2.pem",
    "nodes": []
  }
]

The returned array thus provides information on three trusted CA certificates, which are loaded for the entire cluster. Note that each object in the array has a key-value pair whose key is `id`, and whose corresponding value is an integer that is the id for the specified certificate. This id can be referenced when certificate-deletion is required: see [Delete Root Certificates](delete-trusted-cas.md).

### [](#output-redaction)Output Redaction

Cluster-private information is redacted from returned objects, when the user is unauthorized. For example, the following call is made without authorization:

curl -X GET http://172.23.122.104:8091/pools/default/trustedCAs

Formatted, the output appears as follows:

[
  {
    "id": 0,
    "subject": "CN=Couchbase Server 47ec9560",
    "notBefore": "2013-01-01T00:00:00.000Z",
    "notAfter": "2049-12-31T23:59:59.000Z",
    "pem": "-----BEGIN CERTIFICATE-----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\nC6YKL1Fh\n-----END CERTIFICATE-----\n\n"
  },
  {
    "id": 1,
    "subject": "C=US, ST=New Mexico, L=Albuquerque, O=A1A Car Wash, CN=docker-light-baseimage",
    "notBefore": "2021-01-16T11:42:00.000Z",
    "notAfter": "2026-01-15T11:42:00.000Z",
    "pem": "-----BEGIN CERTIFICATE-----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\nuElSBnLT7DIT3uBSxmIegHNH\n-----END CERTIFICATE-----\n\n"
  }
]

The above output contains only information that can be directly extracted from each certificate.

By contrast, the call immediately below is made with full authorization:

curl -X GET http://172.23.122.104:8091/pools/default/trustedCAs -u Administrator:password

Formatted, the output appears as follows:

[
  {
    "id": 0,
    "subject": "CN=Couchbase Server 47ec9560",
    "notBefore": "2013-01-01T00:00:00.000Z",
    "notAfter": "2049-12-31T23:59:59.000Z",
    "type": "generated",
    "pem": "-----BEGIN CERTIFICATE-----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\nC6YKL1Fh\n-----END CERTIFICATE-----\n\n",
    "warnings": [
      {
        "name": "self_signed",
        "message": "Out-of-the-box certificates are self-signed. To further secure your system, you must create new X.509 certificates signed by a trusted CA.",
        "severity": 2,
        "severityName": "minimal"
      }
    ],
    "nodes": [
      "172.23.122.103:8091",
      "172.23.122.104:8091"
    ]
  },
  {
    "id": 1,
    "loadTimestamp": "2022-04-20T05:31:24.000Z",
    "subject": "C=US, ST=New Mexico, L=Albuquerque, O=A1A Car Wash, CN=docker-light-baseimage",
    "notBefore": "2021-01-16T11:42:00.000Z",
    "notAfter": "2026-01-15T11:42:00.000Z",
    "type": "uploaded",
    "pem": "-----BEGIN CERTIFICATE-----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\nuElSBnLT7DIT3uBSxmIegHNH\n-----END CERTIFICATE-----\n\n",
    "loadHost": "172.23.122.104",
    "loadFile": "/opt/couchbase/var/lib/couchbase/inbox/CA/ldap_ca.pem",
    "warnings": [],
    "nodes": []
  }
]

Thus, since the call was fully authorized, its output contains additional, cluster-private information; including `loadTimestamp`, `type`, `warnings`, `nodes`, `loadHost`, and `loadFile`.

## [](#see-also)See Also

An overview of certificate management is provided in [Certificates](../learn/security/certificates.md). Steps for certificate creation are provided in [Configure Server Certificates](../manage/manage-security/configure-server-certificates.md) and [Configure Client Certificates](../manage/manage-security/configure-client-certificates.md).