### Example Database Shard Files

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/cluster/sharding.md

Illustrates the file structure for database shards within a CouchDB installation.

```text
data/shards/00000000-1fffffff/abc.1529362187.couch
data/shards/20000000-3fffffff/abc.1529362187.couch
data/shards/40000000-5fffffff/abc.1529362187.couch
data/shards/60000000-7fffffff/abc.1529362187.couch
data/shards/80000000-9fffffff/abc.1529362187.couch
data/shards/a0000000-bfffffff/abc.1529362187.couch
data/shards/c0000000-dfffffff/abc.1529362187.couch
data/shards/e0000000-ffffffff/abc.1529362187.couch
```

--------------------------------

### Define Reusable Elixir Setup Function

Source: https://github.com/apache/couchdb/blob/main/test/elixir/README.md

Defines a shared setup function for starting HTTPD and creating an admin user. Promotes code reuse in test setups.

```elixir
defmodule Foo do
  alias Couch.Test.Setup.Step

  def httpd_with_admin(setup) do
    setup
      |> Step.Start.new(:start, extra_apps: [:chttpd])
      |> Step.User.new(:admin, roles: [:server_admin])
  end
end
```

--------------------------------

### Accept Header Example (JSON)

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/basics.md

Demonstrates a GET request with the Accept header set to application/json, ensuring a JSON response.

```APIDOC
## GET /recipes

### Description
This example shows a GET request to the /recipes endpoint with the Accept header explicitly set to application/json, ensuring the response Content-Type is also JSON.

### Method
GET

### Endpoint
/recipes

### Parameters
#### Request Headers
- **Accept** (string) - Required - Specifies the desired response content type, e.g., `application/json`.

### Request Example
```http
GET /recipes HTTP/1.1
Host: couchdb:5984
Accept: application/json
```

### Response
#### Success Response (200)
- **Content-Type** (application/json) - The content type of the response, matching the Accept header.

#### Response Example
```http
HTTP/1.1 200 OK
Server: CouchDB (Erlang/OTP)
Date: Thu, 13 Jan 2013 13:40:11 GMT
Content-Type: application/json
Content-Length: 227
Cache-Control: must-revalidate
```
```

--------------------------------

### Successful GET /_session Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/authn.md

Example response for a successful GET /_session request. Includes user context, authentication info, and configured handlers.

```http
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Length: 175
Content-Type: application/json
Date: Fri, 09 Aug 2013 20:27:45 GMT
Server: CouchDB (Erlang/OTP)
Set-Cookie: AuthSession=cm9vdDo1MjA1NTBDMTqmX2qKt1KDR--GUC80DQ6-Ew_XIw; Version=1; Path=/; HttpOnly

{
    "info": {
        "authenticated": "cookie",
        "authentication_db": "_users",
        "authentication_handlers": [
            "cookie",
            "default"
        ]
    },
    "ok": true,
    "userCtx": {
        "name": "root",
        "roles": [
            "_admin"
        ]
    }
}
```

--------------------------------

### Accept Header Example (Default)

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/basics.md

Demonstrates a GET request without an explicit Accept header, showing the default response Content-Type.

```APIDOC
## GET /recipes

### Description
This example shows a basic GET request to the /recipes endpoint without specifying an Accept header.

### Method
GET

### Endpoint
/recipes

### Request Example
```http
GET /recipes HTTP/1.1
Host: couchdb:5984
Accept: */*
```

### Response
#### Success Response (200)
- **Content-Type** (text/plain;charset=utf-8) - The content type of the response.

#### Response Example
```http
HTTP/1.1 200 OK
Server: CouchDB (Erlang/OTP)
Date: Thu, 13 Jan 2011 13:39:34 GMT
Content-Type: text/plain;charset=utf-8
Content-Length: 227
Cache-Control: must-revalidate
```
```

--------------------------------

### QuickJS Scanner Log Output

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/best-practices/jsdevel.md

Example log output indicating the start and completion of a QuickJS scanner session.

```text
couch_quickjs_scanner_plugin s:1725559802-c615220453e6 starting
...
couch_quickjs_scanner_plugin s:1725559802-c615220453e6 completed
```

--------------------------------

### Finish CouchDB Cluster Setup

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/setup/cluster.md

Run this command on the setup coordination node after all nodes have been added to finalize the cluster setup and add system databases.

```bash
curl -X POST -H "Content-Type: application/json" http://admin:password@<setup-coordination-node>:5984/_cluster_setup -d '{"action": "finish_cluster"}'
```

--------------------------------

### Install CouchDB Snap

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/snap.md

Installs the CouchDB snap package. Ensure snapd is installed first.

```sh
sudo snap install couchdb
```

--------------------------------

### Querying a Partitioned Search Index via Command Line

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/ddocs/search.md

This command-line example uses curl to query a partitioned search index, mirroring the functionality of the HTTP GET request.

```sh
curl https://$HOST:5984/$DATABASE/_partition/$PARTITION_KEY/_design/$DDOC/
_search/$INDEX_NAME?include_docs=true\&query="*:*"\&limit=1 \
```

--------------------------------

### Start CouchDB Service

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/freebsd.md

Start the CouchDB service after enabling it in rc.conf. Use 'onestart' to start it ad-hoc if not yet enabled.

```bash
service couchdb3 start
```

--------------------------------

### Install CouchDB with Homebrew

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/mac.md

Use Homebrew to install the latest version of CouchDB. Ensure Homebrew and its formulae are up-to-date before installing.

```bash
brew update
brew install couchdb
```

--------------------------------

### Integrate Shared Setup in Elixir Tests

Source: https://github.com/apache/couchdb/blob/main/test/elixir/README.md

Demonstrates how to integrate shared setup functions like `httpd_with_admin` into a test suite. Manages context and setup execution.

```elixir
defmodule Couch.Test.CRUD do
  use Couch.Test.ExUnit.Case
  alias Couch.Test.Utils

  alias Couch.Test.Setup

  alias Couch.Test.Setup.Step

  def with_db(context, setup) do
    setup = 
      setup
      |> Setup.Common.httpd_with_db()
      |> Setup.run()

    context = 
      Map.merge(context, %{
        db_name: setup |> Setup.get(:db) |> Step.Create.DB.name(),
        base_url: setup |> Setup.get(:start) |> Step.Start.clustered_url(),
        user: setup |> Setup.get(:admin) |> Step.User.name()
      })

    {context, setup}
  end

  describe "Database CRUD using Fabric API" do
    @describetag setup: &__MODULE__.with_db/2
    test "Create DB", ctx do
      IO.puts("base_url: #{ctx.base_url}")
      IO.puts("admin: #{ctx.user}")
      IO.puts("db_name: #{ctx.db_name}")
    end
  end
end
```

--------------------------------

### Get Cluster Setup State

Source: https://github.com/apache/couchdb/blob/main/src/setup/README.md

Retrieve the current state of the cluster setup process. This is a GET request to the `/_cluster_setup` endpoint.

```http
GET /_cluster_setup
{"state": "cluster_disabled"}
```

```http
GET /_cluster_setup
{"state":"cluster_enabled","nodes":[]}
```

```http
GET /_cluster_setup
{"state":"cluster_finished","nodes":["node a", "node b", ...]}
```

--------------------------------

### Clone and Test CouchDB Setup

Source: https://github.com/apache/couchdb/blob/main/src/setup/README.md

Steps to clone the CouchDB repository, checkout the setup branch, configure, build, and run a test cluster. Includes instructions for running test scripts and resetting instances.

```bash
git clone https://git-wip-us.apache.org/repos/asf/couchdb.git
cd couchdb
git checkout setup
./configure
make
dev/run --no-join -n 2 --admin a:b
```

```bash
src/setup/test/t.sh
```

```bash
rm -rf dev/lib/ dev/logs/
dev/run --no-join -n 2 --admin a:b
```

--------------------------------

### GET /db/_changes Request Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/changes.md

Example of a GET request to the _changes endpoint with the 'all_docs' style parameter to retrieve all document revisions.

```http
GET /db/_changes?style=all_docs HTTP/1.1
Accept: application/json
Host: localhost:5984
```

--------------------------------

### Build CouchDB Documentation

Source: https://github.com/apache/couchdb/blob/main/src/docs/README.md

Install Python 3 and pip, then use these commands to set up a virtual environment, install dependencies, and build the HTML documentation.

```sh
python3 -m venv .venv
source .venv/bin/activate
pip3 install -r requirements.txt
make html # builds the docs
make check # syntax checks the docs
```

--------------------------------

### FoundationDB Skip List Setup and Constants

Source: https://github.com/apache/couchdb/blob/main/src/docs/rfcs/012-fdb-reduce.md

Initializes FoundationDB connection, sets API version, and defines constants for the skip list implementation. Includes setup instructions for running locally.

```javascript
/* To run locally
    npm install foundationdb
    node skiplist.js
*/


const assert = require('assert');
const util = require('util');
const fdb = require('foundationdb');
const ks = require('foundationdb').keySelector;

// CONSTANTS
const SHOULD_LOG = false;
const PREFIX = 'skiplist';
const MAX_LEVELS = 6;
const LEVEL_FAN_POW = 1; // 2^X per level or (1 / 2^X) less than previous level
const END = 0xFF;

fdb.setAPIVersion(600); // Must be called before database is opened
const db = fdb.openSync()
  .at(PREFIX) // database prefix for all operations
  .withKeyEncoding(fdb.encoders.tuple)
  .withValueEncoding(fdb.encoders.json); // automatically encode & decode values using JSON

// Data model
// (level, key) = reduce_value


const log = (...args) => {
    if (!SHOULD_LOG) {
        return;
    }
    console.log(...args);
}
```

--------------------------------

### GET /_all_dbs Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Example JSON response for the GET /_all_dbs request, listing database names. The Content-Type will be application/json.

```json
[
   "_users",
   "contacts",
   "docs",
   "invoices",
   "locations"
]
```

--------------------------------

### Basic local.ini Configuration Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/config/intro.md

This is a standard way to set parameters in the local.ini file. It demonstrates section definitions, parameter specifications, and inline comments.

```ini
; This is a comment
[section]
param = value ; inline comments are allowed
```

--------------------------------

### Start the Nouveau Server

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/nouveau.md

Execute this command to start the Nouveau server. Ensure all necessary JAR files are in the same directory as nouveau.jar.

```bash
java -jar /path/to/nouveau.jar server /path/to/nouveau.yaml
```

--------------------------------

### Get Target Information Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/replication/protocol.md

Example JSON response from a GET request to a target database. Note that `update_seq` can be a string for large databases.

```json
{
    "compact_running": false,
    "db_name": "target",
    "disk_format_version": 5,
    "doc_count": 1832,
    "doc_del_count": 1,
    "instance_start_time": "0",
    "purge_seq": 0,
    "sizes": {
      "active": 50829452,
      "disk": 77001455,
      "external": 60326450
    },
    "update_seq": "1841-g1AAAADveJzLYWBgYMlgTmGQT0lKzi9KdUhJMtbLSs1LLUst0k"
}
```

--------------------------------

### Set up Java and SBT for building Clouseau from source

Source: https://github.com/apache/couchdb/blob/main/README-DEV.rst

Install specific versions of Java and SBT using 'asdf' and set the corresponding CLOUSEAU_JAVA_HOME and CLOUSEAU_SBT_HOME environment variables. This is required when building Clouseau from source for testing.

```bash
asdf install java openjdk-21
```

```bash
asdf plugin add sbt
```

```bash
asdf install sbt 1.11.7
```

```bash
export CLOUSEAU_JAVA_HOME=$(asdf where java openjdk-21)
```

```bash
export CLOUSEAU_SBT_HOME=$(asdf where sbt 1.11.7)
```

--------------------------------

### GET /_scheduler/jobs Response Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

This JSON structure represents the response from a GET request to the /_scheduler/jobs endpoint, detailing active replication jobs.

```json
{
    "jobs": [
        {
            "continuous": false,
            "doc_id": null,
            "doc_write_batch": 1,
            "last_seq": "1-abcdef1234567890abcdef1234567890",
            "replication_id": "rep-12345",
            "source": "http://myserver.com/foo",
            "target": "http://adm:*****@localhost:15984/cdyno-0000002/",
            "worker": "node1@127.0.0.1"
        }
    ],
    "offset": 0,
    "total_rows": 1
 }
```

--------------------------------

### Setup and Indexing Database with Nouveau

Source: https://github.com/apache/couchdb/blob/main/extra/nouveau/README.md

This script sets up a CouchDB database with a Nouveau index definition and populates it with sample data. It demonstrates creating, deleting, and updating documents, and defining index analyzers.

```shell
#!/bin/sh

URL="http://foo:bar@127.0.0.1:15984/foo"

curl -X DELETE "$URL"
curl -X PUT "$URL?n=3&q=16"

curl -X PUT "$URL/_design/foo" -d '{"nouveau":{"bar":{"default_analyzer":"standard", "field_analyzers":{"foo":"english"}, "index":"function(doc) { index(\"string\", \"foo\", \"bar\"); }"}}}'

# curl "$URL/_index" -Hcontent-type:application/json -d '{"type":"nouveau", "index": {"fields": [{"name": \"bar\", \"type\":\"number\"}]}}'

for I in {1..5}; do
    DOCID=$RANDOM
    DOCID=$[ $DOCID % 100000 ]
    BAR=$RANDOM
    BAR=$[ $BAR % 100000 ]
    curl -X PUT "$URL/doc$DOCID" -d "{\"bar\": $BAR}"
done

while true; do
    curl 'foo:bar@localhost:15984/foo/_design/foo/_nouveau/bar?q=*:*'
done
```

--------------------------------

### Get Source Information Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/replication/protocol.md

Example JSON response from a GET request to a source database. The `update_seq` field is crucial for replication progress tracking.

```json
{
    "committed_update_seq": 61772,
    "compact_running": false,
    "db_name": "source",
    "disk_format_version": 6,
    "doc_count": 41961,
    "doc_del_count": 3807,
    "instance_start_time": "0",
    "purge_seq": 0,
    "sizes": {
      "active": 70781613961,
      "disk": 79132913799,
      "external": 72345632950
    },
    "update_seq": 61772
}
```

--------------------------------

### Get Cluster Setup Status

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Retrieves the current state of the node or cluster as part of the cluster setup wizard. It can optionally ensure specific system databases exist.

```APIDOC
## GET /_cluster_setup

### Description
Returns the status of the node or cluster, per the cluster setup wizard.

### Method
GET

### Endpoint
/_cluster_setup

### Parameters
#### Query Parameters
- **ensure_dbs_exist** (array) - Optional - List of system databases to ensure exist on the node/cluster. Defaults to `["_users","_replicator"]`.

### Response
#### Success Response (200)
- **state** (string) - Current `state` of the node and/or cluster. Possible values include `cluster_disabled`, `single_node_disabled`, `single_node_enabled`, `cluster_enabled`, `cluster_finished`.

### Request Example
```http
GET /_cluster_setup HTTP/1.1
Accept: application/json
Host: localhost:5984
```

### Response Example
```json
{
  "state": "cluster_enabled"
}
```
```

--------------------------------

### Query Syntax Examples

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/ddocs/nouveau.md

Examples demonstrating the syntax for constructing search queries.

```APIDOC
## Query Syntax Examples

### Basic Queries
- `class:bird`
- `l*`

### Combined Queries
- `class:bird AND diet:carnivore`
- `l* AND diet:herbivore`
- `min_length:[1 TO 3] AND diet:herbivore`
- `diet:herbivore AND min_length:[* TO 2]`
- `class:mammal AND min_length:[1.5 TO *]`
- `latin_name:"Meles meles"`
- `diet:(herbivore OR omnivore) AND class:mammal`
- `*:*` (Return all results)

### Fuzzy Search
- `look~` (finds terms like 'book' and 'took')

### Operators
- `AND`, `+`, `OR`, `NOT`, `-`
```

--------------------------------

### Create Index with All Query Parameters

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/find.md

This example demonstrates creating a JSON index using all available query parameters, including partial filter selectors, specific fields, design document, name, type, and partitioned status.

```http
POST /db/_index HTTP/1.1
Content-Type: application/json
Content-Length: 396
Host: localhost:5984

{
    "index": {
        "partial_filter_selector": {
            "year": {
                "$gt": 2010
            },
            "limit": 10,
            "skip": 0
        },
        "fields": [
            "_id",
            "_rev",
            "year",
            "title"
        ]
    },
    "ddoc": "example-ddoc",
    "name": "example-index",
    "type": "json",
    "partitioned": false
}
```

--------------------------------

### GET /_dbs_info Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Example JSON response for the GET /_dbs_info request, providing details for each database including update sequence, sizes, and cluster information. The Content-Type will be application/json.

```json
[
  {
    "key": "animals",
    "info": {
      "db_name": "animals",
      "update_seq": "52232",
      "sizes": {
        "file": 1178613587,
        "external": 1713103872,
        "active": 1162451555
      },
      "purge_seq": 0,
      "doc_del_count": 0,
      "doc_count": 52224,
      "disk_format_version": 6,
      "compact_running": false,
      "cluster": {
        "q": 8,
        "n": 3,
        "w": 2,
        "r": 2
      },
      "instance_start_time": "0"
    }
  }
]
```

--------------------------------

### Bulk Get Response for Conflicted Document

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/bulk-api.md

This is a partial response example for a bulk get request. It shows the structure for a single document result, which can contain either the document data (`ok`) or an error.

```json
{
  "results": [
    {
      "id": "a",
      "docs": [
        {

```

--------------------------------

### Create Database and Add Documents

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/cluster/sharding.md

Demonstrates creating a new database and adding two documents to it using curl commands.

```bash
$ curl -X PUT $COUCH_URL:5984/mydb
{"ok":true}
```

```bash
$ curl -X PUT $COUCH_URL:5984/mydb/joan -d '{"loves":"cats"}'
{"ok":true,"id":"joan","rev":"1-cc240d66a894a7ee7ad3160e69f9051f"}
```

```bash
$ curl -X PUT $COUCH_URL:5984/mydb/robert -d '{"loves":"dogs"}'
{"ok":true,"id":"robert","rev":"1-4032b428c7574a85bc04f1f271be446e"}
```

--------------------------------

### Get Cluster Setup Status

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Use this endpoint to check the current state of the node or cluster setup. The `state` field indicates whether the node is disabled, enabled as a single node, or part of a cluster.

```http
GET /_cluster_setup HTTP/1.1
Accept: application/json
Host: localhost:5984
```

```http
HTTP/1.1 200 OK
X-CouchDB-Body-Time: 0
X-Couch-Request-ID: 5c058bdd37
Server: CouchDB/2.1.0-7f17678 (Erlang OTP/17)
Date: Sun, 30 Jul 2017 06:33:18 GMT
Content-Type: application/json
Content-Length: 29
Cache-Control: must-revalidate

{"state":"cluster_enabled"}
```

--------------------------------

### CouchDB Snap Configuration Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/snap.md

Example configuration stanza for CouchDB snap, specifying data and view directories. This is typically placed in `/var/snap/couchdb/current/etc/local.ini`.

```ini
[couchdb]
;max_document_size = 4294967296 ; bytes
;os_process_timeout = 5000
database_dir = /var/snap/couchdb/common/data
view_index_dir = /var/snap/couchdb/common/data
```

--------------------------------

### Enable Cluster Setup

Source: https://github.com/apache/couchdb/blob/main/src/setup/README.md

Initiate the cluster setup process by sending a POST request with the `enable_cluster` action to `/_cluster_setup`. This transitions the state from `cluster_disabled` to `cluster_enabled`.

```http
POST /_cluster_setup {"action":"enable_cluster"...}
```

--------------------------------

### GET /db/_changes Response Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/changes.md

Example JSON response from the _changes endpoint, showing the last sequence number, pending changes, and a list of recent changes including document IDs and revision information.

```json
{
    "last_seq": "5-g1AAAAIreJyVkEsKwjAURZ-toI5cgq5A0sQ0OrI70XyppcaRY92J7kR3ojupaSPUUgotgRd4yTlwbw4A0zRUMLdnpaMkwmyF3Ily9xBwEIuiKLI05KOTW0wkV4rruP29UyGWbordzwKVxWBNOGMKZhertDlarbr5pOT3DV4gudUC9-MPJX9tpEAYx4TQASns2E24ucuJ7rXJSL1BbEgf3vTwpmedCZkYa7Pulck7Xt7x_usFU2aIHOD4eEfVTVA5KMGUkqhNZV-8_o5i",
    "pending": 0,
    "results": [
        {
            "changes": [
                {
                    "rev": "2-7051cbe5c8faecd085a3fa619e6e6337"
                }
            ],
            "id": "6478c2ae800dfc387396d14e1fc39626",
            "seq": "3-g1AAAAG3eJzLYWBg4MhgTmHgz8tPSTV0MDQy1zMAQsMcoARTIkOS_P___7MSGXAqSVIAkkn2IFUZzIkMuUAee5pRqnGiuXkKA2dpXkpqWmZeagpu_Q4g_fGEbEkAqaqH2sIItsXAyMjM2NgUUwdOU_JYgCRDA5ACGjQfn30QlQsgKvcjfGaQZmaUmmZClM8gZhyAmHGfsG0PICrBPmQC22ZqbGRqamyIqSsLAAArcXo"
        },
        {
            "changes": [
                {
                    "rev": "3-7379b9e515b161226c6559d90c4dc49f"
                }
            ],
            "deleted": true,
            "id": "5bbc9ca465f1b0fcd62362168a7c8831",

```

--------------------------------

### POST /_cluster_setup

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Configure a node as a single (standalone) node, as part of a cluster, or finalise a cluster.

```APIDOC
## POST /_cluster_setup

### Description
Configure a node as a single (standalone) node, as part of a cluster,
or finalise a cluster.

### Method
POST

### Endpoint
/_cluster_setup

### Parameters
#### Request Body
- **action** (string) - Required - Specifies the cluster setup action to perform. Possible values: `enable_single_node`, `enable_cluster`, `add_node`, `finish_cluster`.
- **bind_address** (string) - Optional - The IP address to which to bind the current node. `0.0.0.0` binds to all interfaces. (Used with `enable_cluster` and `enable_single_node`)
- **username** (string) - Optional - The username of the server-level administrator to create or the remote server's administrator username. (Used with `enable_cluster`, `enable_single_node`, and `add_node`)
- **password** (string) - Optional - The password for the server-level administrator to create or the remote server's administrator username. (Used with `enable_cluster`, `enable_single_node`, and `add_node`)
- **port** (number) - Optional - The TCP port to bind this node or a remote node. (Used with `enable_cluster`, `enable_single_node`, and `add_node`)
- **node_count** (number) - Optional - The total number of nodes to be joined into the cluster. (Used with `enable_cluster` only)
- **remote_node** (string) - Optional - The IP address of the remote node to setup as part of this cluster's list of nodes. (Used with `enable_cluster` only)
- **remote_current_user** (string) - Optional - The username of the server-level administrator authorized on the remote node. (Used with `enable_cluster` only)
- **remote_current_password** (string) - Optional - The password of the server-level administrator authorized on the remote node. (Used with `enable_cluster` only)
- **host** (string) - Optional - The remote node IP of the node to add to the cluster. (Used with `add_node` only)
- **ensure_dbs_exist** (array) - Optional - List of system databases to ensure exist on the node/cluster. Defaults to `["_users","_replicator"]`.

### Status Codes
- 200 OK - Request completed successfully
- 401 Unauthorized - Unauthorized request to a protected API
- 403 Forbidden - Insufficient permissions / Too many requests with invalid credentials
```

--------------------------------

### Get CouchDB Snap Info

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/snap.md

Displays information about the installed CouchDB snap, including available channels.

```sh
snap info couchdb
```

--------------------------------

### Get Cluster Membership

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Retrieves the nodes participating in the cluster and all known nodes. Useful for cluster setup.

```http
GET /_membership HTTP/1.1
Accept: application/json
Host: localhost:5984
```

```http
HTTP/1.1 200 OK
Cache-Control: must-revalidate
Content-Type: application/json
Date: Sat, 11 Jul 2015 07:02:41 GMT
Server: CouchDB (Erlang/OTP)
Content-Length: 142

{
    "all_nodes": [
        "node1@127.0.0.1",
        "node2@127.0.0.1",
        "node3@127.0.0.1"
    ],
    "cluster_nodes": [
        "node1@127.0.0.1",
        "node2@127.0.0.1",
        "node3@127.0.0.1"
    ]
}
```

--------------------------------

### Install CouchDB using pkg

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/freebsd.md

Use this command to install CouchDB from pre-built binary packages.

```bash
pkg install couchdb3
```

--------------------------------

### Simple Query Examples for FoundationDB

Source: https://github.com/apache/couchdb/blob/main/src/docs/rfcs/012-fdb-reduce.md

Demonstrates various simple query scenarios, including different group levels and key ranges, to verify accuracy.

```javascript
const simpleQueries = async () => {
    let result = {};
    result = await query({group_level: 0});
    assert.deepEqual(result, {
        rows: [{
            key: null,
            value: 68
        }]
    });

    result = await query({group_level:0, startkey: [2018, 3, 2]});
    assert.deepEqual(result, {
        rows: [{
            key: null,
            value: 31
        }]
    });

    result = await query({
        group_level:0,
        startkey: [2018, 3, 2],
        endkey: [2019, 5, 1]
    });
    assert.deepEqual(result, {
        rows: [{
            key: null,
            value: 31
        }]
    });

    result = await query({
        group_level: 0,
        startkey: [2018, 03, 2],
        endkey: [2019, 03, 2],

    })

    assert.deepEqual(result, {
        rows: [{
            key: null,
            value: 18
        }]
    });

    result = await query({
        group_level: 1,
        startkey: [2017, 4, 1],
        endkey: [2018, 3, 1],
    })

    assert.deepEqual(result, {
        rows: [
        {
            key: [2017],
            value: 22
        },
        {
            key: [2018],
            value: 6
        }
    ]
    });

    result = await query({
        group_level: 1,
        startkey: [2017, 4, 1],
        endkey: [2019, 03, 2],

    })

    assert.deepEqual(result, {
        rows: [
        {
            key: [2017],
            value: 22
        },
        {
            key: [2018],
            value: 20
        },
        {
            key: [2019],
            value: 4
        }
    ]
    });

    result = await query({
        group_level: 1,
        startkey: [2017, 4, 1],
        endkey: [2019, 05, 1],

    })

    assert.deepEqual(result, {
        rows: [
        {
            key: [2017],
            value: 22
        },
        {
            key: [2018],
            value: 20
        },
        {
            key: [2019],
            value: 17
        }
    ]
    });

    result = await query({
        group: true,
        startkey: [2018, 5, 1],
        endkey: [2019, 4, 1],
    });

    assert.deepEqual(result, {rows: [
        {key: [2018,5,1], value: 7},
        {key: [2019,3,1], value: 4},
        {key: [2019,4,1], value: 6}
    ]})
    log('SIMPLE DONE');
};
```

--------------------------------

### Using Key Parameters

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/ddoc/views.md

Explains the usage of `key`, `keys`, `start_key`, and `end_key` for precise view querying, including compatibility and precedence rules.

```APIDOC
## Querying Views with Key Parameters

### Description
This section details how to use `key`, `keys`, `start_key`, and `end_key` to query CouchDB views. It covers single and multi-element `keys` and their interaction with other key parameters and `group=true`.

### Method
GET

### Endpoint
/db/_design/ddoc/_view/reduce

### Query Parameters
- **key** (string) - Optional - Filters results to a single specific key. Equivalent to `start_key=$key&end_key=$key`.
- **keys** (array) - Optional - Filters results based on a list of keys. For reduce views, requires `group=true` for multi-element arrays.
- **start_key** (string) - Optional - The lower bound of the key range.
- **end_key** (string) - Optional - The upper bound of the key range.
- **group** (boolean) - Optional - Required when using multi-element `keys` with reduce views.

### Request Examples

#### Using `key`
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?key="a"'
```

#### Using single-element `keys`
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?keys="["a"]"'
```

#### Using multi-element `keys` with `group=true`
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?keys=\"a","c\"]&group=true'
```

#### Using `key` with `endkey` (equivalent to `start_key=a` and `end_key=b`)
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?key="a"&endkey="b"'
```

#### Using `endkey` with `key` (equivalent to `start_key=a` and `end_key=a`)
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&key="a"'
```

#### Using `endkey` with `keys` (single element)
```bash
curl http://adm:pass@127.0.0.1:5984/db/_design/ddoc/_view/reduce'?endkey="b"&keys=\"a\"'
```

### Response
#### Success Response (200)
- **rows** (array) - Contains the view results, with keys and values.

#### Response Example (for `key="a"`)
```json
{
  "rows": [
    {
      "key": null,
      "value": 1
    }
  ]
}
```

#### Response Example (for `keys=["a","c"]&group=true`)
```json
{
  "rows": [
    {
      "key": "a",
      "value": 1
    },
    {
      "key": "c",
      "value": 3
    }
  ]
}
```

### Error Handling
- **query_parse_error**: Returned when `keys` is used with reduce views without `group=true`, or when `keys` is used with `key`, `start_key`, or `end_key`.
```

--------------------------------

### Creating a Database With Correct Admin Credentials

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/intro/security.md

This command shows how to successfully create a database by including valid admin username and password in the URL for basic authentication.

```bash
HOST="http://anna:secret@127.0.0.1:5984"
curl -X PUT $HOST/somedatabase
{"ok":true}
```

--------------------------------

### Get Cluster Membership

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Displays the nodes that are part of the cluster and all nodes the current node is aware of. Useful for cluster setup and management.

```APIDOC
## GET /_membership

### Description
Displays the nodes that are part of the cluster as `cluster_nodes`. The field `all_nodes` displays all nodes this node knows about, including the ones that are part of the cluster. The endpoint is useful when setting up a cluster.

### Method
GET

### Endpoint
/_membership

### Request Headers
- Accept (application/json, text/plain)

### Response Headers
- Content-Type (application/json, text/plain; charset=utf-8)

### Status Codes
- 200 OK - Request completed successfully
- 401 Unauthorized - Unauthorized request to a protected API
- 403 Forbidden - Insufficient permissions / Too many requests with invalid credentials

### Request Example
```http
GET /_membership HTTP/1.1
Accept: application/json
Host: localhost:5984
```

### Response Example
```json
{
    "all_nodes": [
        "node1@127.0.0.1",
        "node2@127.0.0.1",
        "node3@127.0.0.1"
    ],
    "cluster_nodes": [
        "node1@127.0.0.1",
        "node2@127.0.0.1",
        "node3@127.0.0.1"
    ]
}
```
```

--------------------------------

### Verify Cluster Setup

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/setup/cluster.md

Retrieves the current state of the cluster setup process.

```APIDOC
## Verify Cluster Setup

### Description
Checks the status of the cluster setup.

### Method
GET

### Endpoint
`/_cluster_setup`

### Response
#### Success Response (200)
- **state** (string) - The current state of the cluster setup (e.g., `"cluster_finished"`)
```

--------------------------------

### GET /_db_updates Request

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Example HTTP request to retrieve database update events. Ensure the Accept header is set to application/json.

```http
GET /_db_updates HTTP/1.1
Accept: application/json
Host: localhost:5984
```

--------------------------------

### GET /_dbs_info Request

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Example HTTP request to retrieve information about all databases in a CouchDB instance. The Accept header should be set to application/json.

```http
GET /_dbs_info HTTP/1.1
Accept: application/json
Host: localhost:5984
```

--------------------------------

### Finish Cluster Setup

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/setup/cluster.md

This command is run on the setup coordination node to finalize the cluster configuration and add system databases.

```APIDOC
## Finish Cluster Setup

### Description
Completes the cluster setup process and initializes system databases.

### Method
POST

### Endpoint
`/_cluster_setup`

### Request Body
- **action** (string) - Required - Must be `"finish_cluster"`

### Request Example
```json
{
  "action": "finish_cluster"
}
```
```

--------------------------------

### Install runit Package

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/unix.md

Installs the runit package using apt-get on Ubuntu systems.

```sh
sudo apt-get install runit
```

--------------------------------

### JWT Authentication Request

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/authn.md

Example HTTP GET request to the _session endpoint, including the Authorization header with a JWT token for authentication.

```http
GET /_session HTTP/1.1
Host: localhost:5984
Accept: application/json
Content-Type: application/json; charset=utf-8
Authorization: Bearer <JWT token>
```

--------------------------------

### Test Single-Node Setup Script

Source: https://github.com/apache/couchdb/blob/main/src/setup/README.md

Execute the `t-single_node.sh` script in a separate terminal to verify the single-node setup.

```bash
$ src/setup/test/t-single_node.sh
```

--------------------------------

### Finish Cluster Setup

Source: https://github.com/apache/couchdb/blob/main/src/setup/README.md

Complete the cluster setup process by sending a POST request with the `finish_cluster` action. This transitions the state to `cluster_finished`.

```http
POST /_cluster_setup {"action":"finish_cluster"}
```

--------------------------------

### GET /_all_dbs Request

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/server/common.md

Example HTTP request to retrieve a list of all databases in a CouchDB instance. Ensure the Accept header is set to application/json.

```http
GET /_all_dbs HTTP/1.1
Accept: application/json
Host: localhost:5984
```

--------------------------------

### Bulk GET Response Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/bulk-api.md

Illustrates the structure of a successful response from the _bulk_get endpoint, showing retrieved documents or errors for missing ones.

```json
{
  "results": [
    {
      "ok": {
        "_id": "a",
        "_rev": "1-23202479633c2b380f79507a776743d5",
        "a": 1
      }
    },
    {
      "ok": {
        "_id": "a",
        "_rev": "1-967a00dff5e02add41819138abb3284d"
      }
    }
  ]
}
```

--------------------------------

### Create a Partitioned Database

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/partitioned-dbs/index.md

Use the `partitioned=true` query parameter when creating a new database to enable partitioning.

```bash
shell> curl -X PUT 'http://adm:pass@127.0.0.1:5984/my_new_db?partitioned=true'
{"ok":true}
```

--------------------------------

### Default View Sorting

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/ddoc/views.md

This example shows a GET request to a view endpoint without any sorting parameters, demonstrating the default UTF-8 sorting order.

```APIDOC
## GET /db/_design/test/_view/sorting

### Description
Retrieves view results sorted according to CouchDB's default UTF-8 sorting rules.

### Method
GET

### Endpoint
/db/_design/test/_view/sorting

### Parameters
#### Query Parameters
- **descending** (boolean) - Optional - If true, reverses the sort order.

### Request Example
```http
GET /db/_design/test/_view/sorting HTTP/1.1
Accept: application/json
Host: localhost:5984
```

### Response
#### Success Response (200)
- **offset** (integer) - The offset where the returned rows start.
- **rows** (array) - An array of view result objects, each containing 'id', 'key', and 'value'.
- **total_rows** (integer) - The total number of rows in the view.

#### Response Example
```json
{
    "offset": 0,
    "rows": [
        {
            "id": "dummy-doc",
            "key": null,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": false,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": true,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": 0,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": 1,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": 10,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": 42,
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": "10",
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": "hello",
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": "Hello",
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": "\u043f\u0440\u0438\u0432\u0435\u0442",
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": [],
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": [
                1,
                2,
                3
            ],
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": [
                2,
                3
            ],
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": [
                3
            ],
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": {},
            "value": null
        },
        {
            "id": "dummy-doc",
            "key": {
                "foo": "bar"
            },
            "value": null
        }
    ],
    "total_rows": 17
}
```
```

--------------------------------

### Setup Skip List and Insert Initial Key-Value Pairs

Source: https://github.com/apache/couchdb/blob/main/src/docs/rfcs/012-fdb-reduce.md

Initializes the skip list by inserting a base key '0' with value 0 at all levels, then inserts a predefined set of key-value pairs.

```javascript
const create = async () => {
    await db.doTransaction(async tn => {
        for(let level = 0; level <= MAX_LEVELS; level++) {
            await insertAtLevel(tn, '0', 0, level);
        }
    });

    log('setup done');
    for ([key, val] of kvs) {
        await db.doTransaction(async tn => {
            await insert(tn, key, val);
        });
    }
};
```

--------------------------------

### Bulk GET Request Example

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/database/bulk-api.md

Demonstrates how to retrieve multiple documents from a database using the _bulk_get endpoint. Specify document IDs and optionally revisions.

```json
{
  "docs": [
    { "id": "a", "rev": "1-23202479633c2b380f79507a776743d5" },
    { "id": "b" },
    { "id": "c", "rev": "1-967a00dff5e02add41819138abb3284d" }
  ]
}
```

--------------------------------

### Basic Attachments Info Request

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/document/common.md

This is an example of an HTTP GET request to retrieve a document that includes attachment metadata. The `Accept` header specifies that JSON is expected.

```http
GET /recipes/SpaghettiWithMeatballs HTTP/1.1
Accept: application/json
Host: localhost:5984
```

--------------------------------

### Create runit Configuration Directories

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/unix.md

Sets up the necessary directory structure for runit's CouchDB service configuration.

```sh
sudo mkdir /etc/sv/couchdb
sudo mkdir /etc/sv/couchdb/log
```

--------------------------------

### Basic Nouveau Server Configuration

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/install/nouveau.md

This is a sample `nouveau.yaml` file. Refer to the DropWizard documentation for a full list of configuration options.

```yaml
maxIndexesOpen: 100
commitIntervalSeconds: 30
idleSeconds: 60
rootDir: target/indexes
```

--------------------------------

### GET Nouveau Index Info Response

Source: https://github.com/apache/couchdb/blob/main/src/docs/src/api/ddoc/nouveau.md

Example JSON response for a successful request to the Nouveau Info API. This response includes details about the specified search index.

```json
HTTP/1.1 200 OK
Content-Type: application/json

{
    "name": "_design/cookbook/ingredients",
    "search_index": {
        "num_docs": 1000,
        "update_seq": 5000,
        "disk_size": 1048576
    }
}
```

--------------------------------

### Start CouchDB as CouchDB User

Source: https://github.com/apache/couchdb/blob/main/INSTALL.Unix.md

Start the CouchDB server as the dedicated `couchdb` user using `sudo`. This is the recommended way for the first run.

```bash
sudo -i -u couchdb couchdb/bin/couchdb
```