Add Autocomplete to Your Application

Capella Operational

how-to

March 23, 2025

+ 12

Use autocomplete to add suggestions for a user’s Search query as they type in your application.

After you create and configure a Search index that supports autocomplete, configure your application to return results from the Search Service.

Prerequisites

You have the Search Service enabled on a node in your cluster. For more information about how to change Services on your cluster, see Modify a Paid Cluster.
You have a bucket with scopes and collections in your cluster. For more information, see Manage Buckets.
You have the hostname for the node in your cluster that’s running the Search Service.

Go to your cluster settings and click Nodes to view node hostnames.
You have created a compatible Search index. For more information, see Configure an Autocomplete Search Index.
You have created cluster access credentials that have Read/Write permissions on the bucket and scope where you created your Search index. For more information, see Configure Cluster Access Credentials.

Procedure

To add autocomplete with the Search Service to your application:

Test that your Search index was configured correctly by running a Search query from the Capella UI with 2-8 characters in the Search field.

For example, with the travel-sample bucket, you could enter the strings Be, Bea, Beau, and Beauf to find a document with the text Beaufort Hotel.

Configure your application to return results from the Search Service.

The following examples simulate a user typing an input string and return search results for each partial string:

C#
Go
Java
JavaScript
Python

csharp
ViewCopy
using Couchbase;
using Couchbase.Search.Queries.Simple;

await using var cluster = await Cluster.ConnectAsync(new ClusterOptions
{
    ConnectionString = "CB_HOSTNAME",
    UserName = "CB_USERNAME",
    Password = "CB_PASSWORD",
    Buckets = new List<string>{"travel-sample"}
}.ApplyProfile("wan-development"));

var searchString = "Beaufort Hotel";
for (var i = 2; i <= 8; i++)
{
    var lettersEntered = searchString.Substring(0, i);
    Console.WriteLine($"Input <{lettersEntered}>, len: {lettersEntered.Length}");
    await FtsMatchPrefix(lettersEntered);
}

async Task FtsMatchPrefix(string letters)
{
    try
    {
        var results = await cluster.SearchQueryAsync("e-ngram-2-8",
            new QueryStringQuery(letters),
            options =>
            {
                options.Limit(8);
                options.Fields("name");
            });
        results.Hits.ToList().ForEach(row => { Console.WriteLine($"{row.Id}, {row.Fields}"); });
        Console.WriteLine(results);
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
    }
}

go
ViewCopy
package main

import (
    "os"
    "fmt"
    "math"
    "log"
    "github.com/couchbase/gocb/v2"
    "github.com/couchbase/gocb/v2/search"
)

func main() {
    cluster, err := gocb.Connect(
	os.Getenv("CB_HOSTNAME"),                    
	gocb.ClusterOptions{
        Authenticator: gocb.PasswordAuthenticator{
            Username: os.Getenv("CB_USERNAME"),      
            Password: os.Getenv("CB_PASSWORD"),      
        },
    })
    if err != nil {
        log.Fatal(err)
    }

    iterStr := "Beaufort Hotel"
    maxsz := int(math.Min(float64(len(iterStr)), float64(8)))
    for i := 2;  i <= maxsz; i++ {
        testStr := iterStr[0:i]
	fmt.Printf("Input <%s>, len: %d\n", testStr, len(testStr));
	results, err := cluster.SearchQuery(
	    "e-ngram-2-8",
	    search.NewQueryStringQuery(testStr), 
	    &gocb.SearchOptions { Fields: []string{"name"}, Limit: 8, },
	)
	if err != nil {
	    log.Fatal(err)
	}

	for results.Next() {
	    row := results.Row()
	    docID := row.ID
	    var fields interface {}
	    err := row.Fields( & fields)
	    if err != nil {
		panic(err)
	    }
	    fmt.Printf("Document ID: %s, fields: %v\n", docID, fields)
	}

	err = results.Err()
	if err != nil {
	    log.Fatal(err)
	}
    }
}

java
ViewCopy
import com.couchbase.client.java.Cluster;
import com.couchbase.client.java.json.JsonObject;
import com.couchbase.client.java.search.SearchOptions;
import com.couchbase.client.java.search.SearchQuery;
import com.couchbase.client.java.search.result.SearchResult;
import com.couchbase.client.java.search.result.SearchRow;

public class MockTypeAheadEnGram {
  static String connstrn = System.getenv("CB_HOSTNAME"); 
  static String username = System.getenv("CB_USERNAME"); 
  static String password = System.getenv("CB_PASSWORD"); 
  
  public static void main(String... args) {
    Cluster cluster = Cluster.connect(connstrn, username, password);
    
    String iterStr = "Beaufort Hotel";
    for (int i=2; i<=Math.min(8, iterStr.length());i++) {
    	String testStr = iterStr.substring(0, i);
    	System.out.println("Input <" + testStr + ">, len: " + testStr.length());
    
    	SearchQuery query = SearchQuery.queryString(testStr);
    	SearchOptions options = SearchOptions.searchOptions().limit(8).skip(0).explain(false).fields("name");
    	SearchResult result = cluster.searchQuery("e-ngram-2-8" , query, options);
    	for (SearchRow row : result.rows()) {
    		System.out.println(row.id() + "," + row.fieldsAs(JsonObject.class) );
    	}
    }
  }
}

javascript
ViewCopy
const couchbase = require('couchbase')

const main = async () => {
  const hostname = process.env.CB_HOSTNAME
  const username = process.env.CB_USERNAME
  const password = process.env.CB_PASSWORD
  const bucketName = 'travel-sample'

  const cluster = await couchbase.connect(hostname, {username: username, password: password })

  const ftsMatchPrefix = async (term) => {
    try {
      const result =  await cluster.searchQuery(
        "e-ngram-2-8",
        couchbase.SearchQuery.queryString(term), { limit: 8, fields: ["name"] }
      )
      result.rows.forEach((row) => { console.log(row.id,row.fields)})
    } catch (error) {
      console.error(error)
    }
  }

  const inputStr = "Beaufort Hotel"
  for (let i = 2; i <= 8; i++) {
    var testStr = inputStr.substring(0, i);
    console.log("Input <" + testStr + ">, len: " + testStr.length)
    const res = await ftsMatchPrefix(testStr)
  }
}

main()

python
ViewCopy
from couchbase.cluster import Cluster, ClusterOptions
from couchbase.auth import PasswordAuthenticator
from couchbase.exceptions import CouchbaseException
import couchbase.search as search
import os

username = os.getenv("CB_USERNAME", default=None)
password = os.getenv("CB_PASSWORD", default=None)
hostname = os.getenv("CB_HOSTNAME", default=None)

cluster = Cluster.connect(
    "couchbase://" + hostname,
    ClusterOptions(PasswordAuthenticator(username,password)))

try:
    inputStr = "Beaufort Hotel"
    for i in range(2, min(8,len(inputStr))):
        testStr = inputStr[0:i]
        print("Input <" + testStr + ">, len: " + str(len(testStr)));

        result = cluster.search_query(
            "e-ngram-2-8", 
            search.QueryStringQuery(testStr),
            search.SearchOptions(limit=8, fields=["name"]))

        for row in result.rows():
            print(row.id,row.fields)

except CouchbaseException as ex:
    import traceback
    traceback.print_exc()

Next Steps

After you add autocomplete to your application, to improve your search results, you can:

Add additional features to your Search index from the UI.
Change the JSON payload for your Search index.