Implement a search box

This is for:

Developer

In this article

Standard search box actions
Submit a query
Correct queries
Provide Coveo Machine Learning query suggestions
Provide field-based query completion suggestions
Enable advanced search box features

A search interface typically includes a text input from which users can enter and submit queries. This article provides guidelines for implementing a search box on your own, assuming that you can’t use the Coveo JavaScript Search Framework or the Atomic or Headless libraries in your custom search integration with the Coveo Platform.

Note

As a reference, you may want to look at the source code of the Searchbox component to see how it’s implemented in the Coveo JavaScript Search Framework.

The following table lists some actions that you may want to make available in a search box implementation.

Each entry indicates the specific Coveo Usage Analytics (Coveo UA) event type, actionCause, and customData that must be logged (if applicable) when the action is performed, as well as a link to the corresponding implementation guidelines.

Search box action Event category actionCause customData Implementation guidelines

Search box action	Event category	`actionCause`	`customData`	Implementation guidelines
Submit a query	Search	`searchboxSubmit` or `searchFromLink` (standalone search box)		Submit a query
Clear the search box	Search	`searchboxClear`		Submit a query
Select a query correction suggestion	Search	`didyoumeanClick`		Correct queries
Trigger an automatically corrected query	Search	`didyoumeanAutomatic`		Correct queries
Render Coveo ML suggestions	Search			Provide Coveo Machine Learning query suggestions
Select a Coveo ML suggestion	Search	`omniboxAnalytics` or `omniboxFromLink` (standalone search box)	`partialQueries`, `partialQuery`, `suggestionRanking`, `suggestions`	Handle Coveo Machine Learning query suggestion selection
Render field-based suggestions	Search			Provide field-based query completion suggestions
Select a field-based suggestion	Search	`omniboxField`		Handle field-based query completion suggestion selection

Submit a query

searchboxSubmit or searchFromLink (standalone search box)

Submit a query

Clear the search box

searchboxClear

Submit a query

Select a query correction suggestion

didyoumeanClick

Correct queries

Trigger an automatically corrected query

didyoumeanAutomatic

Correct queries

Render Coveo ML suggestions

Provide Coveo Machine Learning query suggestions

Select a Coveo ML suggestion

omniboxAnalytics or omniboxFromLink (standalone search box)

partialQueries, partialQuery, suggestionRanking, suggestions

Handle Coveo Machine Learning query suggestion selection

Render field-based suggestions

Provide field-based query completion suggestions

Select a field-based suggestion

omniboxField

Handle field-based query completion suggestion selection

Note

Using the proper event type, actionCause, and customData when logging a UA event for a specific type of action in a search interface is important. Otherwise:

UA reports may become incoherent in the underlying Coveo organization (especially if that organization powers both {javascript-search-interface} and custom search interfaces).
The Coveo Machine Learning (Coveo ML) service may not function properly.

Submit a query

When the user submits a query from the search box (for example, by clicking Submit):

Retrieve the current value from the search box input.
Prepare a new query. Ensure that the q search request parameter is set to the value retrieved in step 1.
Call the Search API to execute the query prepared in step 2. When the Search API returns:
1. Call the UA Write API to log the corresponding search event. In the request body:
  - Set the actionCause property to searchboxSubmit.
    
    Note
    
    If the user triggered a query by clearing the search box (for example, by clicking Clear), set the actionCause property to searchboxClear instead.
  - Set other required or optional properties as needed.
2. Render the query results.
3. Render the facets, if any.

Executing the query after the expression catcher rye has been submitted from the search box:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "q": "catcher rye",
  "locale": "en-US",
  "searchHub": "BookstoreSearch",
  "tab": "All",
  ...
}

200 OK response body (excerpt)

{
  ...
  "duration": 145,
  "searchUid": "9862eba6-b30b-491b-94af-33ca2fd61547",
  "results": [
    ...data to render query results...
  ],
  "groupByResults": [
    ...data to render facets...
  ],
  ...
}

Logging a searchboxSubmit search event after the Search API has returned:

POST https://myorganizationid9sd8df7s.analytics.org.coveo.com/rest/ua/v15/analytics/search?visitor=28s6g49d-f81s-1435-2r5x153dle72 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "actionCause": "searchboxSubmit",
  "queryText": "catcher rye",
  "language": "en",
  "originLevel1": "BookstoreSearch",
  "originLevel2": "All",
  "responseTime": 145,
  "searchQueryUid": "9862eba6-b30b-491b-94af-33ca2fd61547",
  ...
}

Note

As shown in this example, whenever logging a search event:

queryText corresponds to q in the query request body.
language corresponds to the language part of locale in the query request body.
originLevel1 corresponds to searchHub in the query request body.
originLevel2 corresponds to tab in the query request body.

Moreover:

responseTime corresponds to the elapsed time (in milliseconds) between the moment the search interface sent the query to the Search API, and the moment it received the results.
searchQueryUid corresponds to searchUid in the query response body.

When the user submits a query from the standalone search box (for example, by clicking Submit):

Retrieve the current value from the standalone search box input.
(Optional) If you want the standalone search box to be able to handle redirect query pipeline trigger rules:
1. Get the execution plan of the query by sending a GET request to https://<orgId>.org.coveo.com/rest/search/v2/plan, where <orgId> is the unique identifier of your organization.
  
  authenticate the request using an access token that grants the privilege to execute queries. Set the q query parameter of the request to the value retrieved in step 1.
2. In the response body, if the triggers object of the preprocessingOutput property doesn’t contain an element whose type is redirect, skip directly to step 3. Otherwise, retrieve the content value from that element and then:
  1. Call the UA Write API to log a custom event.
    
    In the request body:
    
    Set eventValue to redirect
    
    Set eventType to queryPipelineTriggers
    
    In the customData property, set redirectedTo to the content value retrieved in step 2.b.
    
    Set other required or optional properties as needed.
  2. Skip to step 4, where you’ll redirect using the content value retrieved in step 2.b.
Call the UA Write API to log the corresponding search event. In the request body:
- Set the actionCause property to searchFromLink.
- Set other required or optional properties as needed.
Redirect the browser.

If you’re redirecting to a full search interface that can display the results, you can forward the basic query expression (q) to the interface by passing it as a query parameter in the URL and ensuring that the target interface is able to retrieve and parse it.

Correct queries

The DidYouMean query feature enables the Search API to check for a possible query correction if a query returns no results. You can configure this feature to either suggest the correction, or automatically trigger a new query with the suggested term. The DidYouMean feature involves the enableDidYouMean (Boolean) search request parameter.

When enableDidYouMean is set to true, the Search API returns the queryCorrections object in the query response body if no results are returned (for example, "totalCount": 0).

To suggest the query correction in the search interface after a user has entered a query that returned no results:

Retrieve the value of the correctedQuery parameter from within the queryCorrections query response object.
Use the value from Step 1 to output a message suggesting the corrected query. This message should include a link. When the user clicks that link:
1. Prepare a new query. Ensure that the q search request parameter is set to the value retrieved in step 1 (see Submit a query).
2. Call the Search API to execute the query prepared in step 2. When the Search API returns:
  1. Call the UA Write API to log the corresponding search event. In the request body:
    
    Set the actionCause property to didyoumeanClick.
    
    Set other required or optional properties as needed.

Note

You may want to use the wordCorrections array from the queryCorrections object to output a string indicating what was wrong in the original query.

Alternatively, you can enable your search interface to automatically correct queries and display results without requiring the user to interact more with the search interface. To do so, follow the preceding steps but make the following changes:

Automatically trigger the query from Step 2.a, rather than wait for a user to select a correction link.
Set the actionCause property to didyoumeanAutomatic when logging the corresponding search event from Step 2.b.i.

Note

You should typically output a string to the user indicating that the query was automatically corrected.

Examples of correcting queries

Executing a query after the expression The Shning has been submitted from the search box:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2?organizationId=myorganizationid HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  "aq": "@source==\"MovieSource\"",
  "q": "Shning",
  "enableDidYouMean": true
  // additional parameters...
}

200 OK response body (excerpt)

{
  "totalCount": 0,
  ...
  "queryCorrections": [
    {
      "correctedQuery": "shining",
      "wordCorrections": [
        {
          "offset": 0,
          "length": 7,
          "originalWord": "shning",
          "correctedWord": "shining"
        }
      ]
    }
  ],
  ...
}

Using the correctedWord value as the q parameter for the new query:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2?organizationId=myorganizationid HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  "aq": "@source==\"MovieSource\"",
  "q": "shining",
  "enableDidYouMean": true
  // additional parameters...
}

200 OK response body (excerpt)

{
"totalCount": 1,
...
"results": [
  {
    "title": "The Shining",
    ...
  }
],
...
}

Logging a didyoumeanAutomatic custom event after the Search API has returned:

POST https://myorganizationid9sd8df7s.analytics.org.coveo.com/rest/ua/v15/analytics/search?visitor=28s6g49d-f81s-1435-2r5x153dle72 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "actionCause": "didyoumeanAutomatic",
  "queryText": "The Shining",
  "language": "en",
  "originLevel1": "MoviestoreSearch",
  "originLevel2": "Classics",
  "responseTime": 118,
  "searchQueryUid": "8c2f6897-203d-4d5c-db56-5b3e39831345",
  ...
}

Provide Coveo Machine Learning query suggestions

Once you’ve logged enough usage analytics data in your Coveo organization, and created a Coveo Machine Learning Query Suggestions (QS) model, you can assist users by providing them with highly relevant, Coveo ML-powered query suggestions as they’re typing in the search box.

Note

No UA event needs to be logged when requesting Coveo ML-based query suggestions.

To do so, on each valid keystroke in the search box:

Retrieve the current value from the search box input.
Resolve the current searchHub, {tab}, and locale (and, optionally, the referrer and context) search request parameters.

Call the Search API to get query suggestions. In the request body:

Set the q property to the value retrieved in step 1.
Set the searchHub, {tab}, and locale (and, optionally, referrer and context for finer granularity) parameters to the values resolved in step 2 to get contextually relevant Coveo ML-based query suggestions.
Set the enableWordCompletion property to true if you want the top query suggestion in the request response to be the one that best completes the last word being typed by the user in the search box. If you set this property to false, the top query completion suggestion will instead be the one deemed most relevant by the QS model (even if this query suggestion doesn’t actually complete the query).

When calling the Search API to get query suggestions, the request must be routed to a query pipeline in which a Coveo ML QS model is configured and ready. Otherwise, the request will return an empty completions array.

When the Search API returns, use the expression and/or highlighted properties of each element in the ordered completions array of the response body to render query suggestions in a dedicated list.

Note

In a completions array item:

The score property value only has relative significance within the same completions array.

For example, a suggestion with a score of 14.811407079917723 in the completions array of response A isn’t necessarily less relevant than a suggestion with a score of 24.325728875625282 in the completions array of response B.
The highlighted property uses the following logic:
- Characters between curly braces, such as {cat}, indicate an exact match with q.
- Characters between square brackets, such as [cher], indicate completions.
- Characters between parentheses, such as (act), indicate corrections to q.
The executableConfidence property contains a floating-point value between 0 and 1 indicating how "convinced" Coveo ML is that performing a query with this suggestion as a basic query expression (q) will return relevant results. The threshold at which Coveo ML considers a query suggestion executable is 0.8.

You could use this property to include a reliable search-as-you-type feature in your search box implementation.

Example of providing Coveo ML query suggestions

Requesting Coveo ML-based query suggestions:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2/querySuggest HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload

{
  "q": "cat",
  "locale": "en-US",
  "searchHub": "BookstoreSearch",
  "tab": "All",
  "referrer": "https://example.com/books/classics/authors/Salinger_J_D/",
  "context": {
    "userType": "Premium"
  },
  "enableWordCompletion": false
}

Successful response - 200 OK

{
  "completions": [
    {
      "expression": "catcher in the rye",
      "score": 14.811407079917723,
      "highlighted": "{cat}[cher] [in] [the] [rye]",
      "executableConfidence": 1
    },
    {
      "expression": "dream catcher",
      "score": 14.135665512605295,
      "highlighted": "[dream] {cat}[cher]",
      "executableConfidence": 1.0
    },
    {
      "expression": "catch-22",
      "score": 13.576942132468472,
      "highlighted": "{cat}[ch-22]",
      "executableConfidence": 1
    },
    {
      "expression": "cat in the hat",
      "score": 12.879732037029243,
      "highlighted": "{cat} [in] [the] [hat]",
      "executableConfidence": 1.0
    },
    {
      "expression": "the children act",
      "score": 12.325728875625282,
      "highlighted": "[the] [children] (act)",
      "executableConfidence": 0.6666666666666666
    },
  ]
}

Handle Coveo Machine Learning query suggestion selection

When the user selects a query suggestion, such as by clicking one of the rendered suggestions:

Set the search box input value to the query suggestion that the user has selected.
Prepare a new query. Ensure that the q search request parameter is set to the expression generated in step 1.
Call the Search API to execute the query prepared in step 2. When the Search API returns:
1. Call the UA Write API to log the corresponding search event.
  
  In the request body:
  - Set the actionCause property to omniboxAnalytics (or omniboxFromLink in a standalone search box).
  - Include the following key-value pairs in the customData property:
    
    "partialQueries": <partialQueries>
    
    "partialQuery": <partialQuery>
    
    "suggestionRanking": <suggestionRanking>
    
    "suggestions": <suggestions>
    
    where:
    
    <partialQueries> (semicolon-separated ordered list of strings) contains the q value of each Search API query suggestion request that returned at least one suggestion, before a suggestion was selected.
    
    <partialQuery> (string) is the q value of the last Search API query suggestion request made before a suggestion was selected.
    
    <suggestionRanking> (unsigned integer) is the 0-based index position of the suggestion that was selected in the completions array.
    
    <suggestions> (semicolon-separated ordered list of strings) contains the expression value of each item in the response of the last Search API query suggestion request.
    
    Example
    
    A user types c, i, [backspace], o, and v in the search box. At this point, the following ordered list of query suggestions is displayed:
    
    coveo for salesforce
    
    coveo for sitecore
    
    coveo
    
    coveo for servicenow
    
    coveo for zendesk
    
    The user selects the third item in the list (coveo).
    
    In the customData property of the search event that gets logged when the triggered query returns:
    
    <partialQueries> would have to be set to c;ci;c;co;cov.
    
    <partialQuery> would have to be set to cov.
    
    <suggestionRanking> would have to be set to 2.
    
    <suggestions> would have to be set to coveo for salesforce;coveo for sitecore;coveo;coveo for servicenow;coveo for zendesk.
    
    Set other required or optional properties as needed.
2. Render the query results.
3. Render the facets, if any.

Examples of handling Coveo ML query suggestion selection

Executing a query after the dream catcher query completion suggestion has been selected:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "q": "dream catcher",
  "firstResult": 0,
  "locale": "en-US",
  "searchHub": "BookstoreSearch",
  "tab": "All",
  "referrer": "https://example.com/books/classics/authors/Salinger_J_D/",
  "context": {
    "userType": "Premium"
  },
  ...
}

Logging an omniboxField search event after the Search API has returned:

POST https://myorganizationid9sd8df7s.analytics.org.coveo.com/rest/ua/v15/analytics/search?visitor=28s6g49d-f81s-1435-2r5x153dle72 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "actionCause": "omniboxAnalytics",
  "customData": {
    ...
    "partialQueries": "c;ca;car;ca;cat",
    "partialQuery": "cat",
    "suggestionRanking": 1,
    "suggestions": "catcher in the rye;dream catcher;catch-22;cat in the hat;the children act",
    "context_userType": "Premium",
    ...
  },
  "queryText": "dream catcher",
  "language": "en",
  "originLevel1": "BookstoreSearch",
  "originLevel2": "All",
  "responseTime": 97,
  "searchQueryUid": "153fdc38-8eb9-428a-942d-19a6ddb59fe9",
  ...
}

Note

As shown in this example, when logging a search event, customData must contain a corresponding context_-prefixed key along with its value for each key-value pair in the context object of the query request body.

Provide field-based query completion suggestions

Typically, you should only use Coveo ML QS in your search box implementation, as it’s both powerful and relatively easy to implement (see Provide Coveo Machine Learning query suggestions). However, it’s also possible (although not necessarily recommended) to assist users by providing them with field-based query completion suggestions as they’re typing in the search box.

Example

In a bookstore search interface, you may want to suggest @author field values that match what the user is typing.

Note

No UA event needs to be logged when requesting field values.

To render field-based query completion suggestions, on each valid keystroke in the search box:

Retrieve the current value from the search box input.

Modify the retrieved value to a wildcard expression. For example, if the value retrieved in step 1 was a, set it to *a*.

Note

These guidelines assume that you’re using the wildcards patternType when requesting field values from the Search API, because this is how field suggestions are implemented in the Coveo JavaScript Search Framework (see the FieldsSuggestion component). You can use any other valid patternType value (regularExpression, editDistance, or phonetic) in your own implementation if you so desire.

If your search interface includes tabs, retrieve the filter expression enforced by the currently selected tab.
Call the Search API to get matching field values. In the request body:
- Set the patternType property to wildcards.
- Set the pattern property to the value modified in step 2 (for example, *a*).
- Set the field property to the @-prefixed name of the field from which to retrieve query completion suggestions (for example, @author).
  
  field-based query completion suggestions can only be retrieved from fields whose facet option is set to true (see Available Boolean field options).
- Set the sortCriteria property to occurrences to ensure that field suggestions are returned in a logical order.
- Set the maximumNumberOfValues property to a relatively low value (for example, 5) to ensure that only a useful number of field suggestions are requested.
- When users may use accented characters, set the ignoreAccents property to true to ensure that accented characters are treated as non-accented characters when retrieving field values. For example, when ignoreAccents is set to true, using *élo* or *elo* as a pattern value is equivalent; both may return field values such as Hello or Éloïse.
- If your search interface includes tabs, set the queryOverride property to the value retrieved in step 3 to ensure that only field suggestions matching the expression enforced by the currently selected tab are returned.
When the Search API returns, use the value property of each element in the ordered values array of the response body to render field suggestions in a dedicated list.

Example of providing field-based query completion suggestions

Requesting query completion suggestions based on the @author field:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2/values HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload

{
  "patternType": "wildcards",
  "pattern": "*a*",
  "field": "@author",
  "sortCriteria": "occurrences",
  "maximumNumberOfValues": 5,
  "ignoreAccents": true,
  "queryOverride": "@source==\"Classics\""
}

Successful response - 200 OK

{
  "values": [
    {
      "value": "Mark Twain",
      "lookupValue": "Mark Twain",
      "numberOfResults": 25
    },
    {
      "value": "Charles Dickens",
      "lookupValue": "Charles Dickens",
      "numberOfResults": 21
    },
    {
      "value": "Jane Austen",
      "lookupValue": "Jane Austen",
      "numberOfResults": 12
    },
    {
      "value": "Charlotte Brontë",
      "lookupValue": "Charlotte Brontë",
      "numberOfResults": 8
    },
    {
      "value": "Mary Shelley",
      "lookupValue": "Mary Shelly",
      "numberOfResults": 5
    }
  ]
}

Handle field-based query completion suggestion selection

When the user selects a specific field-based query completion suggestion (for example, by clicking one of the rendered values):

Generate an expression from the field value the user has selected (for example, Alice Smith).
Set the search box input value to the query expression generated in step 1.

Prepare a new query. Ensure that the q search request parameter is set to the expression generated in step 1.

Note

If the expression generated in step 1 uses advanced query syntax (for example, @author=="Alice Smith"), also ensure that the enableQuerySyntax search request parameter is set to true before the query is executed.

Call the Search API to execute the query prepared in step 3. When the Search API returns:
1. Call the UA Write API to log the corresponding search event. In the request body:
  - Set the actionCause property to omniboxField.
  - Set other required or optional properties as needed.
2. Render the query results.
3. Render the facets, if any.

Examples of handling field-based query completion suggestion selection

Executing a query after the Charles Dickens query completion suggestion has been selected:

POST https://myorganizationid9sd8df7s.org.coveo.com/rest/search/v2 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "q": "@author==\"Charles Dickens\"",
  "enableQuerySyntax": true,
  "firstResult": 0,
  "locale": "en-US",
  "searchHub": "BookstoreSearch",
  "tab": "Classics",
  ...
}

Note

In this example, the basic query expression (q) generated from the selected field value uses advanced query syntax (@author=="Charles Dickens"). Therefore, the enableQuerySyntax search request parameter is set to true to ensure that the Search API parses this expression correctly.

Logging an omniboxField search event after the Search API has returned:

POST https://myorganizationid9sd8df7s.analytics.org.coveo.com/rest/ua/v15/analytics/search?visitor=28s6g49d-f81s-1435-2r5x153dle72 HTTP/1.1

Accept: application/json
Content-Type: application/json
Authorization: Bearer **********-****-****-****-************

Payload (excerpt)

{
  ...
  "actionCause": "omniboxField",
  "queryText": "@author==\"Charles Dickens\"",
  "language": "en",
  "originLevel1": "BookstoreSearch",
  "originLevel2": "Classics",
  "responseTime": 118,
  "searchQueryUid": "8c8f5897-233d-4b4c-bd56-5b3e39885345",
  ...
}

Several search request parameters can have a direct and significant impact on the way the Search API and the index interpret the basic part of the query expression (q). Therefore, in a typical search interface, those search request parameters should logically be configurable through the search box.

You may want to ensure that your search box implementation includes options to enable and take advantage of the following features.

Partial match

The partial match feature can help the index find items that match the basic part of the query expression (q), even when the expression is fairly wordy. This feature involves the following search request parameters:

partialMatch (Boolean)
partialMatchKeywords (unsigned integer)
partialMatchThreshold (unsigned integer or string [percentage])

When partialMatch is set to true and the q value contains at least partialMatchKeywords (for example, 5), items only need to match partialMatchThreshold (for example, 50%, rounded up) of those keywords to match the basic query expression (q).

Note

The partial match feature:

Applies after the query has been fully processed by the query pipeline.
Has no effect when enableQuerySyntax is set to true and q contains advanced query syntax.

Partial match example

Enabling the partial match feature:

Query payload

{
  "q": "the life and strange surprising adventures of robinson crusoe of york mariner",
  "partialMatch": true,
  "partialMatchKeywords": "3",
  "partialMatchThreshold": "35%"
}

In this example, since partialMatch is set to true and q contains 12 keywords:

The basic query expression (q) is converted to a partial match expression (12 is greater than the partialMatchKeywords value of 3).
Any item matching a minimum of 5 keywords in the partial match expression (that is, the partialMatchThreshold value of 35% multiplied by 12, and then rounded up) will match the expression.

This means that, for example, an item which contains the keywords the adventures of robinson crusoe will match the expression.

Wildcards

The wildcards feature allows the index to recognize wildcards characters in the basic part of the query expression (q) and expand the expression accordingly. This feature involves the following search request parameters:

wildcards (Boolean)
questionMark (Boolean)

When wildcards is set to true, * characters in q are interpreted as wildcards.

When questionMark is also set to true, ? characters in q are also treated as wildcards.

Note

Setting questionMark to true has no effect unless wildcards is also set to true.

Wildcards example

Enabling and using the * and ? wildcards:

Query payload

{
  "q": "?obi*",
  "wildcards": true,
  "questionMark": true,
}

In this example, since wildcards and questionMark are both set to true, q is expanded so that items containing keywords such as robin, robinson, jobim, or mobile, will match the expression.

Advanced query syntax

The advanced query syntax feature allows the index to recognize Coveo query syntax in the basic part of the query expression (q) and interpret the expression accordingly. This feature involves the following search request parameters:

enableQuerySyntax (Boolean)
lowercaseOperators (Boolean)

When enableQuerySyntax is set to true, Coveo query syntax in q is interpreted as such.

When lowercaseOperators is also set to true, Boolean operators (NEAR, NOT, AND, and OR) in q are always interpreted as such, even if they appear in lowercase (see Query syntax).

Notes

In most public deployments, enableQuerySyntax should be set to false by default.

Typically, users aren’t going to be aware of Coveo query syntax and will either not use it, or use it inappropriately. Exact phrase match requests (keywords between double quotes) are still going to work even if enableQuerySyntax is set to true, and wildcards (* and ?) can also be enabled independently.
Setting lowercaseOperators to true has no effect unless enableQuerySyntax is also set to true.

Advanced query syntax example

Enabling and using advanced query syntax:

Query payload
```
{
  "q": "@title=prometheus NOT (@author=Shelley)",
  "enableQuerySyntax": true
}
```
In this example, since enableQuerySyntax is set to true, q is parsed so that items whose title contains the keyword prometheus and whose author name doesn’t contain the keyword Shelley will match the expression.

This means that book items corresponding to Frankenstein or the Modern Prometheus (by Mary Shelley) and Prometheus Unbound (by Percy Bysshe Shelley) won’t match the expression. However, a book item such as The Prometheus Effect (by David Fleming) will match the expression.
Enabling and using lowercase operators:

Query payload
```
{
  "q": "doctor strangelove or how i learned to stop worrying and love the bomb",
  "enableQuerySyntax": true,
  "lowercaseOperators": true
}
```
In this example, because enableQuerySyntax and lowercaseOperators are both set to true, the Search API parses the basic query expression (q) as follows: (doctor strangelove) OR (how i learned to stop worrying) AND (love the bomb), which is likely not what the user wants. Setting lowercaseOperators to true should only be done under specific circumstances and is typically not recommended.