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What It Does:

Computes potential reach ( impressions) based on the targeting and schedule settings of a given ad group.
Allows developers to simulate changes to ad group configuration by overriding certain fields in the request payload.
Does not persist or modify ad group data — it is strictly a forecasting tool
To return a valid reach estimate, the following ad group-level attributes must be available either in the stored ad group OR passed in the request : schedule and targeting.

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Simulation (“What-If” analysis) support:

You can override ad group-level startDate, endDate and targeting in the request body to simulate changes without modifying the actual ad group.
Campaign-level schedules that cascade to ad groups cannot yet be simulated in this API. If budget, schedule and deliverySpeed are set at the campaign level, the API will disregard these values if passed, and the forecast provided will use the original campaign values instead.
All overrides are non-persistent. This API does not modify stored campaign or ad group data.

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URL:POST /api/v2/reachEstimate

Request Parameters

Parameters	Notes	Type	Required	Possible Values
advertiserId	ID of advertiser	integer	Y	Unique numeric identifier
campaignId	ID of the campaign	integer	Y	Unique numeric identifier
adGroupId	ID the ad group	integer	N	Unique numeric identifier
metric	The list of metrics you are requesting an estimate for. over the entire forecast window reach aggregated over the entire time of the duration	array	Y	IMPRESSIONS, UNIQUE_HOUSEHOLDS
startDate	Simulated start date for ad group scheduling Note: If startDate has been set at the campaign level for the specified ad group: the startDate value passed in the API request is ignored, and the forecast in the response is based on the startDate of the campaign If startDate has been set at the ad group level for the specified ad group: the forecast is based on the startDate value in the request, not the original value set at the ad group level	datetime	N	Date must follow this format: yyyy-MM-dd'T'HH:mm:ss.SSSXXX Note: All timestamp values must be in ISO 8601 format (e.g., "2025-07-20T19:10:10-05:00"). All date-time values are internally converted to Eastern Time (ET) for processing and normalized to the start of the hour. This means minutes and seconds are truncated. Example: "2025-07-20T19:10:10-05:00" becomes "2025-07-20T19:00:00-05:00" in ET Kindly take these behaviors into consideration when assigning a value to startDate in your request.
endDate	Simulated end date for ad group scheduling. For ad groups that run indefinitely, use the value: endDate = ‘9999-12-30T00:00:00Z’ Note: If endDate has been set at the campaign level for the specified ad group: the endDate value passed in the API request is ignored. Instead, the forecast returned in the response is based on the endDate of the campaign If endDate has been set at the ad group level for the specified ad group: the forecast is based on the endDate value in the request, not the original value set at the ad group level.	datetime	N	Date must follow this format: yyyy-MM-dd'T'HH:mm:ss.SSSXXX *Note:* All timestamp values must be in ISO 8601 format (e.g., "2025-07-20T19:10:10-05:00"). All date-time values are internally converted to Eastern Time (ET) for processing and normalized to the start of the hour. This means minutes and seconds are truncated. Example: "2025-07-20T19:10:10-05:00" becomes "2025-07-20T19:00:00-05:00" in ET The endDate must be set to a time after 12:00 PM ET. If the provided value is before 12:00 PM ET, the system will return an error. Special Case: If you set endDate to exactly "00:00:00" ET (e.g., "2025-07-20T00:00:00-05:00"), it will be interpreted as the end of the previous day: "2025-07-19T23:59:59-05:00". Kindly take these behaviors into consideration when assigning a value to startDate in your request.
targeting	Defines the audience, contextual, keyword, and geographic targeting criteria for an ad group. This object supports both. Supports both expression-based and flattened targeting structure View more details about the targeting object and its schema structures from the Ad group documentation here Note: You must choose one structure; mixing flat and expression-based schemas in a single payload is not supported.	object	Conditional*	The values: • keywords • contextual • behavioral • runOfSite • geoTargets
timeframes	Specifies the timeframes for which forecasts should be returned. If not provided, forecasts for all available timeframes will be returned.	array	N	The values: • daily • 30days • lifetime

*Conditional - required if not configured for the adGroupId
Note: If adGroupId is not provided, startDate, endDate, and targeting should be mandatorily passed and the forecast returned should be based on the specified values of startDate, endDate, and targeting .

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Rules

To return a valid reach estimate, the following ad group-level attributes must be available either in the stored ad group OR passed in the request: startDate, endDate, and targeting
If any of these are missing in the ad group and not provided in the request payload, the API returns an error.
If the following request parameters are set at the campaign level: startDate, endDate, the values for these parameters in the request payload are disregarded and the forecast response uses the original campaign values instead.
If the following request parameters are set at the ad group level: startDate, endDate, and targeting, the values provided for these parameters in the request payload override the original values set at ad group level and are used in the forecast response instead
Users can simulate changes by overriding ad group-level settings in the request payload. The API does not modify any stored data.
Note: Currently, the API supports simulation only for ad group-level attributes. Campaign-level budgets or schedules that apply to ad groups are not yet supported for simulation.
Only one of flat or expression-based schemas can be be provided for targeting object in a single payload

Headers

Header Name	Description	Required	Values
`Authorization`	The token will provide you the access to the API. It is same for all advertisers you access through the API.	Y	Please utilize the generated `auth_token` shared with you at the time of partner onboarding from the Getting Started Guide
`Content-Type`	Format of the message body	Y	application/json
`WM_CONSUMER.ID`	Unique ID for consumer. We will provide you the consumer ID to access the API. It is same for all advertisers you access through the API.	Y	Please use the generated `ConsumerId` shared with you at the time of partner onboarding. Refer to the Getting Started Guide for more information
`WM_SEC.AUTH_SIGNATURE`	Auth signature as an API key.	Y	Use the signature generator code from Getting Started Guide to generate this value
`WM_SEC.KEY_VERSION`	Key version. We will provide you with the KEY VERSION to access the API. It is same for all advertisers you access through the API.	Y	1
`WM_CONSUMER.intimestamp`	Timestamp for which the auth signature is generated. Use Unix epoch format for the timestamp.	Y	Use the signature generator code from Getting Started Guide to generate this value

Sample Request - Get impressions forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

curl--request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: *************' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "impressions" ], "timeframes":["daily","30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "and": [ { "runOfSite": true }, { "geoTargets": [ { "id": 2 } ] } ] }
}'

Sample Request - Get impressions forecast for an ad group with updated values for schedule and targeting(Flattened Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "impressions" ], "timeframes":["daily","30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "runOfSite": true, "geoTargets": { "include": [ { "id": 2 } ] } }
}'

Sample Request - Get unique_households forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "unique_households" ], "timeframes":["30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "and": [ { "runOfSite": true }, { "geoTargets": [ { "id": 2 } ] } ] }
}'

Sample Request - Get unique_households forecast for an ad group with updated values for schedule and targeting (Flattened Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "unique_households" ], "timeframes":["30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "runOfSite": true, "geoTargets": { "include": [ { "id": 2 } ] } }
}'

Sample Request: Ex- 2 Get unique_households forecast for an ad group with updated values for schedule and targeting(Expression based Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "impressions","unique_households" ], "timeframes":["daily","30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "and": [ { "runOfSite": true }, { "geoTargets": [ { "id": 2 } ] } ] }
}'

Sample Request: Ex- 2 Get unique_households forecast for an ad group with updated values for schedule and targeting(Flattened Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '
{ "advertiserId": 1, "campaignId": 9, "adGroupId": 2, "metric": [ "impressions","unique_household" ], "timeframes":["daily","30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "runOfSite": true, "geoTargets": { "include": [ { "id": 2 } ] } }
}'

Sample Request: Get impressions forecast for an ad group without the adgroupId with updated values for schedule and targeting(Expression based Targeting Structure)

curl --location --request POST 'https://developer.api.us.walmart.com/api-proxy/service/display/api/v1/api/v2/reachEstimate' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <auth_token>' \ --header 'WM_SEC.AUTH_SIGNATURE: ***********' \ --header 'WM_CONSUMER.ID: abcde-v123-fa2r-a1fs-asd45f6qef' \ --header 'WM_SEC.KEY_VERSION: 1' \ --header 'WM_CONSUMER.intimestamp: 1565309779' \ --data '
{ "advertiserId": 1, "campaignId": 9, "metric": [ "impressions" ], "timeframes":["daily","30days","lifetime"], "startDate": "2024-06-27T00:00:00Z", "endDate": "2024-12-30T23:59:59Z", "targeting": { "and": [ { "runOfSite": true }, { "geoTargets": [ { "id": 2 } ] } ] }
}

Response

Element	Description	Required	Type	Possible Values
code	The response code can have value: success	Y	string	success
forecastId	forecastId for every successful response	N	string
estimates	Contains forecasted metrics over various time ranges. It is a nested json object that contains forecast data for impressions and uniqueHouseholds Supported metrics: impressions: Estimated number of ad impressions uniqueHouseholds: Estimated number of unique household reach *The estimates objects are detailed below in a separate table following this one.*	Y	json
details	Details of the response. Values: REACH_ESTIMATE_SUCCESS REACH_ESTIMATE_FAILURE	Y	string

estimates Objects

The estimates object contains forecasted metrics across multiple time ranges. Each supported metric is represented as a nested object with estimated ranges. Each metric object may include one or more time-range sub-objects.

Object structure

"estimates": { "<metric>": { "daily": { ... }, "30days": { ... }, "lifetime": { ... } }
}

Time-Range Sub-Objects: Each metric can contain the following optional sub-objects

Elements	Description	Required	Type
daily	Estimated metric values per day	N	object
30days	Estimated metric values for 30 days	N	object
lifetime	Estimated metric values for the ad group's full lifetime	N	object

Estimate range Object: Each time-range object (daily, 30days, lifetime) contains the estimated range values described below

Elements	Description	Required	Type
minValue	Lower bound of the estimated metric range	Y	int
maxValue	Upper bound of the estimated metric range *Note:*This field is omitted when there is no defined upper bound for the estimate	Y	int
scale	The relative scale of the forecast (applicable to impressions metric only) Values: LOW MODERATE HIGH	Y	string

Error Response

Field	Description	Optional field/Nullable?	Type	Possible values
code	Possible values of response code: failure Click here for more information about Status Codes and Errors	N	string	failure
details	List of error codes associated with the request. Use these codes for programmatic error handling.	N	array	Refer to this link for detailed error messages
message	High-level summary of the error, when available.	Y	string
errors	Detailed information about one or more errors, including the affected field (when applicable), error code, and a human-readable description.	Y	array<object>

errors array object details

Field	Description	Optional field/Nullable?	Type
field	JSON field associated with the error. Omitted if the error applies to the request as a whole.	Y	string
errorType	Machine-readable error code that uniquely identifies the error condition. Applications should use this value for error handling logic.	N	string
description	Human-readable explanation of the error, including why the request failed and, when possible, how to resolve it	N	string

Sample Response Success - Get impressions forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

{ "code": "success", "forecastId": "abc-123", "estimates": { "impressions": { "daily": { "minValue": 1, "maxValue": 15, "scale": "LOW" }, "30days": { "minValue": 5, "maxValue": 75, "scale": "MODERATE" }, "lifetime": { "minValue": 1, "maxValue": 15, "scale": "HIGH" } } "details": ["REACH_ESTIMATE_SUCCESS"] }
}

Sample Response Failure - Get impressions forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

{ "code": "failure", "details": [ "string" ],    "message": "string",
    "errors": [ { "field": "string", "errorType": "string", "description": "string" } ] }

Sample Response Success - Get impressions forecast for an ad group with updated values for schedule and targeting(Flattened Targeting Structure)

{ "code": "success", "forecastId": "abc-123", "estimates": { "impressions": { "daily": { "minValue": 1, "maxValue": 15, "scale": "LOW" }, "30days": { "minValue": 5, "maxValue": 75, "scale": "MODERATE" }, "lifetime": { "minValue": 1, "maxValue": 15, "scale": "HIGH" } } "details": ["REACH_ESTIMATE_SUCCESS"] }
}

Sample Response Failure - Get impressions forecast for an ad group with updated values for schedule and targeting(Flattened Targeting Structure)

{ "code": "failure", "details": [ "string" ],    "message": "string",
    "errors": [ { "field": "string", "errorType": "string", "description": "string" } ] }

Sample Response Success - Get unique_households forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)


{ "code": "success", "forecastId": "abc-101", "estimates": { "uniqueHouseholds": { "daily": { "minValue": 346602, "maxValue": 577670 }, "30days": { "minValue": 10561900, "maxValue": 17603167 }, "lifetime": { "minValue": 16983502, "maxValue": 28305837 } } }, "details": ["REACH_ESTIMATE_SUCCESS"]
}

Sample Response Failure - Get unique_households forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

{ "code": "failure", "details": [ "string" ],    "message": "string",
    "errors": [ { "field": "string", "errorType": "string", "description": "string" } ] }

Sample Response Success - Get unique_households forecast for an ad group with updated values for schedule and targeting (Flattened Targeting Structure)

{ "code": "success", "forecastId": "abc-101", "estimates": { "uniqueHouseholds": { "daily": { "minValue": 346602, "maxValue": 577670 }, "30days": { "minValue": 10561900, "maxValue": 17603167 }, "lifetime": { "minValue": 16983502, "maxValue": 28305837 } } }, "details": [ "REACH_ESTIMATE_SUCCESS" ]
}

Sample Response Failure - Get unique_households forecast for an ad group with updated values for schedule and targeting (Flattened Targeting Structure)

{ "code": "failure", "details": [ "string" ],    "message": "string",
    "errors": [ { "field": "string", "errorType": "string", "description": "string" } ] }

Sample Response Success: Ex- 2 Get unique_households forecast for an ad group with updated values for schedule and targeting (Expression based Targeting Structure)

{ "code": "success", "forecastId": "abc-123", "estimates": { "impressions": { "daily": { "minValue": 1, "maxValue": 15, "scale": "LOW" }, "30days": { "minValue": 5, "maxValue": 75, "scale": "MODERATE" }, "lifetime": { "minValue": 1, "maxValue": 15, "scale": "HIGH" } }, "uniqueHouseholds": { "daily": { "minValue": 346602, "maxValue": 577670 }, "30days": { "minValue": 10561900, "maxValue": 17603167 }, "lifetime": { "minValue": 16983502, "maxValue": 28305837 } } "details": ["REACH_ESTIMATE_SUCCESS"] }
}

Sample Response Success: Ex- 2 Get unique_households forecast for an ad group with updated values for schedule and targeting (Flattened Targeting Structure)

{ "code": "success", "forecastId": "abc-123", "estimates": { "impressions": { "daily": { "minValue": 1, "maxValue": 15, "scale": "LOW" }, "30days": { "minValue": 5, "maxValue": 75, "scale": "MODERATE" }, "lifetime": { "minValue": 1, "maxValue": 15, "scale": "HIGH" } }, "uniqueHouseholds": { "daily": { "minValue": 346602, "maxValue": 577670 }, "30days": { "minValue": 10561900, "maxValue": 17603167 }, "lifetime": { "minValue": 16983502, "maxValue": 28305837 } } "details": ["REACH_ESTIMATE_SUCCESS"] }
}

Sample Response Success: Get impressions forecast for an ad group without the adgroupId with updated values for schedule and targeting(Expression based Targeting Structure)

{ "code": "success", "forecastId": "abc-123", "estimates": { "impressions": { "daily": { "minValue": 1, "maxValue": 15, "scale": "LOW" }, "30days": { "minValue": 5, "maxValue": 75, "scale": "MODERATE" }, "lifetime": { "minValue": 1, "maxValue": 15, "scale": "HIGH" } } "details": [ "REACH_ESTIMATE_SUCCESS" ] } }
}