SMS Campaign API Documentation

Creating, costing, sending and controlling bulk SMS campaigns, plus the supporting endpoints for gateways, merge tags, saved templates and one-off messages.

The shape of a campaign

A campaign moves through a fixed set of states, and most endpoints here only accept it in some of them.

Status	Meaning
Draft	Being edited. The only status in which a campaign can be changed
Scheduled	Waiting for its ScheduledAt to pass
Queueing	Its audience is being resolved and queue rows written
Sending	Rows are being released to the gateway
Paused	Stopped by a user, or automatically on a cost drift
Cancelling	Winding down; workers are stopping cleanly
Sent, Cancelled, Failed	Final

The usual sequence is: smscampaign.create, then smscampaign.estimate and smscampaign.estimate.get to obtain a confirmation token, then smscampaign.send or smscampaign.schedule with that token. smscampaign.pause, .resume and .cancel control it afterwards.

A campaign cannot be sent without a cost estimate

smscampaign.send and smscampaign.schedule both require an EstimateID and a ConfirmationToken, and refuse without them. This is deliberate: it is what guarantees the cost a sender approved is the cost they are charged. Estimating is not an optional preview step, it is part of sending.

Campaign management

Create a Campaign

POST /api/v1/smscampaign.create

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 100 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

The campaign is created as a Draft. Its list must have a mobile phone number field configured, which list.sms.settings.update sets.

The audience is the whole list, a saved segment of it (SegmentID), or conditions from the segment rule builder (RulesJsonBundle). It is never both a segment and conditions. While the campaign is a Draft, smscampaign.update can change it, and smscampaign.audience.count counts an audience before anything is saved.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.create
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
CampaignName	String	Yes	A name for the campaign
ListID	Integer	Yes	The audience list. Must belong to the caller and have a phone field
MessageContent	String	Yes	The message body. May contain merge tags from sms.mergetags.get, written as in email: {{ Subscriber:FirstName }}, or {{ Subscriber:FirstName | "there" }} with a fallback. A tag naming a field the list does not have is refused
GatewayID	Integer	No	The sending gateway. Must be active and assigned to the account
SegmentID	Integer	No	Narrow the audience to a saved segment of that list. Cannot be combined with RulesJsonBundle
RulesJsonBundle	String	No	Narrow the audience with conditions, as a JSON-encoded bundle holding exactly one criterion for ListID: {"operator":"or","criteria":[{"list_id":42,"operator":"and","rules":[...]}]}. rules takes the same shape as a saved segment's rules. The criterion's operator joins its rule groups, and the rules inside a group are joined the other way (see the example below). Possible values: and, or. Cannot be combined with SegmentID. Omit it to send to the whole list
SenderID	String	No	The sender number or alphanumeric id to send from
AppendOptOutFooter	Boolean	No	Append the opt-out footer. Defaults to the account setting
OptOutFooterText	String	No	Override the footer text for this campaign
Timezone	String	No	The timezone quiet hours and the schedule are evaluated in, as an IANA name such as Europe/Istanbul. Defaults to the account's own timezone. An unknown name is refused

Example Request

curl -X POST https://example.com/api/v1/smscampaign.create \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.create",
    "SessionID": "your-session-id",
    "CampaignName": "October promotion",
    "ListID": 42,
    "MessageContent": "Hi {FirstName}, 20% off this week only.",
    "GatewayID": 3
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "SMSCampaignID": 4821
}

Error Response

{
  "Success": false,
  "Errors": [
    {
      "Code": 5,
      "Message": "This list has no mobile phone number field configured, so it cannot be an SMS campaign audience."
    }
  ],
  "ErrorCode": 5
}

Error Codes

0: Success
1: Missing CampaignName parameter
2: Missing ListID parameter
3: Missing MessageContent parameter
4: Invalid ListID
5: The list has no mobile phone number field, so it cannot be an SMS audience
6: A link in MessageContent could not be used
7: MessageContent is empty
8: Invalid GatewayID, or the gateway is not available to this account
9: The message is too long for the gateway's concatenation limit
10: The campaign could not be created
11: Invalid SegmentID, or the segment does not belong to this list (also returned when the campaign could not be created as a single transaction)
12: The audience conditions in RulesJsonBundle cannot be used; the message says why
13: SegmentID and RulesJsonBundle were both sent
14: MessageContent uses a merge tag for a field this list does not have; the message names it
15: The list's fields could not be read to check the merge tags, so nothing was created
16: MessageContent has a merge tag that cannot be read (a misspelt or email-only scope, or a space after the colon), which would be sent as typed; the message lists them
17: Timezone is not a known timezone

An audience narrowed by conditions. Here, contacts whose phone number starts with a UK mobile prefix and who have the tag with id 7. The two rules are in separate groups because the criterion's operator joins groups, while the rules inside one group are joined the other way: under and, a group's rules are alternatives. Putting both rules in one group would select contacts matching either of them.

{
  "operator": "or",
  "criteria": [
    {
      "list_id": 42,
      "operator": "and",
      "rules": [
        [ { "type": "fields", "field_id": "CustomField12", "operator": "begins with", "value": "447" } ],
        [ { "type": "tags", "operator": "has this tag", "value": "7" } ]
      ]
    }
  ]
}

TIP

Conditions that could not be applied in full are refused rather than read as "everyone", so a bundle can never silently widen an audience. That covers empty rules, empty groups, and rules nested more than three levels deep (a top-level list of rules or groups, groups of rules or subgroups, subgroups of rules only), which the segment engine would otherwise ignore. To send to the whole list, omit RulesJsonBundle.

Update a Campaign

POST /api/v1/smscampaign.update

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 100 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

Only a Draft campaign can be updated. Every update bumps the campaign's modification time and changes its content fingerprint, which invalidates any estimate taken before it: after updating, run the estimate again before sending.

The audience can be changed too, while the campaign is a Draft. Only what you send changes, with two rules:

• SegmentID and RulesJsonBundle replace each other. Sending one clears the other, so SegmentID=0 or RulesJsonBundle="" sends to the whole list.
• Changing ListID without sending either of them resets the audience to the whole new list, because a segment and a set of conditions each belong to the old list.

The audience is part of the content fingerprint, so an audience change invalidates an earlier estimate like any other edit.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.update
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
SMSCampaignID	Integer	Yes	The campaign to update. Must be in Draft
CampaignName	String	No	A new name
ListID	Integer	No	Move the campaign to another list. Must belong to the caller and have a phone field
SegmentID	Integer	No	Narrow the audience to a saved segment of the list. 0 clears it. Cannot be combined with RulesJsonBundle
RulesJsonBundle	String	No	Narrow the audience with conditions, in the same format as smscampaign.create. An empty string clears them. Cannot be combined with SegmentID
MessageContent	String	No	A new message body
GatewayID	Integer	No	A different gateway
SenderID	String	No	A different sender id
AppendOptOutFooter	Boolean	No	Whether to append the opt-out footer
OptOutFooterText	String	No	Override the footer text
Timezone	String	No	The quiet-hours timezone, as an IANA name. An unknown name is refused

Example Request

curl -X POST https://example.com/api/v1/smscampaign.update \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.update",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "MessageContent": "Hi {FirstName}, 25% off this week only."
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 7, "Message": "The campaign could not be updated, so nothing was changed." }],
  "ErrorCode": 7
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: Only a Draft campaign can be edited
4: A link in MessageContent could not be used
5: MessageContent is empty
6: Nothing to update
7: The campaign could not be updated, so nothing was changed
8: Invalid GatewayID, or the gateway is not available to this account
9: The message is too long for the gateway's concatenation limit
10: The campaign could not be updated as a single transaction, so nothing was changed
11: The campaign, or its links, could not be read, so nothing was changed
12: Invalid ListID
13: The list has no mobile phone number field, so it cannot be an SMS audience
14: Invalid SegmentID, or the segment does not belong to this list
15: The audience conditions in RulesJsonBundle cannot be used; the message says why
16: SegmentID and RulesJsonBundle were both sent
17: The message uses a merge tag for a field the campaign's list does not have, checked whenever the message or the list changes; the message names it
18: The list's fields could not be read to check the merge tags, so nothing was changed
19: The message has a merge tag that cannot be read, which would be sent as typed; the message lists them
20: Timezone is not a known timezone

Count an Audience

POST /api/v1/smscampaign.audience.count

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 60 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

Counts an audience without saving anything, so it works before a campaign exists. It is the same count the estimate starts from: the list, narrowed by a saved segment or by conditions, limited to subscribed contacts.

It is not the number that will be sent. Invalid numbers, suppressed numbers and duplicates are removed afterwards, by smscampaign.estimate, which remains the only number a send is confirmed against.

The count is capped one above the per-campaign maximum. An audience above it is reported as the maximum with ExceedsMaximum set, and a campaign with that audience cannot be sent.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.audience.count
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
ListID	Integer	Yes	The list to count. Must belong to the caller and have a phone field
SegmentID	Integer	No	Count a saved segment of the list. Cannot be combined with RulesJsonBundle
RulesJsonBundle	String	No	Count the contacts matching these conditions, in the same format as smscampaign.create. Cannot be combined with SegmentID

Example Request

curl -X POST https://example.com/api/v1/smscampaign.audience.count \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.audience.count",
    "SessionID": "your-session-id",
    "ListID": 42,
    "SegmentID": 7
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "TotalAudience": 18240,
  "ExceedsMaximum": false,
  "MaxRecipients": 1000000
}

Error Response

{
  "Success": false,
  "Errors": [
    {
      "Code": 7,
      "Message": "This audience uses a segment that picks contacts at random, which an SMS campaign cannot use: every page of the send would pick a different set of contacts."
    }
  ],
  "ErrorCode": 7
}

Error Codes

0: Success
1: Missing ListID parameter
2: Invalid ListID
3: The list has no mobile phone number field, so it cannot be an SMS audience
4: Invalid SegmentID, or the segment does not belong to this list
5: The audience conditions in RulesJsonBundle cannot be used; the message says why
6: SegmentID and RulesJsonBundle were both sent
7: The audience uses a segment that picks contacts at random, which an SMS campaign cannot use
8: The audience uses a segment saved in an older rules format; open it in the segment editor and save it again
9: The audience could not be counted right now

Get a Campaign

GET /api/v1/smscampaign.get

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get
• Legacy endpoint access via /api.php is also supported

QuietHours says whether the campaign's quiet hours are holding it right now. While Active is true a Sending campaign sends nothing, and ResumesAt (UTC) is when it starts again. Start and End are in the campaign's Timezone, and both are null when the campaign has no quiet hours.

The campaign's audience is RelListID, narrowed by at most one of RelSegmentID (a saved segment) and RulesJsonBundle (conditions, as the JSON string it was saved as). Both are null when the campaign goes to the whole list.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.get
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to read

Example Request

curl -X GET https://example.com/api/v1/smscampaign.get \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.get",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "SMSCampaign": {
    "SMSCampaignID": 4821,
    "CampaignName": "October promotion",
    "Status": "Sending",
    "StatusReason": "",
    "RelListID": 42,
    "RelSegmentID": null,
    "RulesJsonBundle": "{\"operator\":\"or\",\"criteria\":[{\"list_id\":42,\"operator\":\"and\",\"rules\":[[{\"type\":\"fields\",\"field_id\":\"CustomField12\",\"operator\":\"begins with\",\"value\":\"447\"}]]}]}",
    "RelGatewayID": 3,
    "MessageContent": "Hi {{ Subscriber:FirstName | \"there\" }}, 20% off this week only.",
    "Timezone": "America/New_York",
    "TotalAudience": 400318,
    "ConfirmedCost": "4315.66000",
    "CostCurrency": "USD"
  },
  "Links": [],
  "IsEditable": false,
  "QuietHours": {
    "Active": true,
    "Start": "21:00",
    "End": "09:00",
    "Timezone": "America/New_York",
    "ResumesAt": "2026-09-23 13:00:00"
  }
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 2, "Message": "Campaign not found." }],
  "ErrorCode": 2
}

Error Codes

0: Success
1: Missing SMSCampaignID parameter
2: Campaign not found
4: The campaign's links could not be read

List Campaigns

GET /api/v1/smscampaign.browse

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get
• Legacy endpoint access via /api.php is also supported

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.browse
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
Status	String	No	Filter by status. Possible values: Draft, Scheduled, Queueing, Sending, Paused, Cancelling, Cancelled, Sent, Failed
ListID	Integer	No	Only campaigns targeting this list
RecordsPerRequest	Integer	No	Page size, default 25, clamped to 200
RecordsFrom	Integer	No	Offset, default 0
CreatedAfter	String	No	Only campaigns created at or after this point. YYYY-MM-DD or YYYY-MM-DD HH:MM:SS; a bare date means 00:00:00
CreatedBefore	String	No	Only campaigns created at or before this point. YYYY-MM-DD or YYYY-MM-DD HH:MM:SS; a bare date means 23:59:59, so the whole day is included

Example Request

curl -X GET https://example.com/api/v1/smscampaign.browse \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.browse",
    "SessionID": "your-session-id",
    "Status": "Sending",
    "RecordsPerRequest": 25
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "Campaigns": [
    { "SMSCampaignID": 4821, "CampaignName": "October promotion", "Status": "Sending" }
  ],
  "TotalCampaigns": 1
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 1, "Message": "Invalid Status value." }],
  "ErrorCode": 1
}

Error Codes

0: Success
1: Invalid Status value
2: The campaign list could not be read
3: Invalid CreatedAfter or CreatedBefore value

Results are ordered newest first by SMSCampaignID and the order cannot be changed. A CreatedAfter or CreatedBefore value that cannot be parsed is refused with ErrorCode 3 rather than ignored, so a malformed date never silently widens the window.

Get a Campaign Summary

GET /api/v1/smscampaign.summary.get

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get
• Legacy endpoint access via /api.php is also supported

Counts and totals across every campaign matching the filters, rather than across one page of smscampaign.browse. Intended for a dashboard header or a status rail: it answers how many campaigns sit in each status and what the whole selection sent, delivered, cost and lost to opt-outs, in two grouped queries rather than one call per status.

Takes the same ListID and CreatedAt filters as smscampaign.browse, so a summary and a list read under the same parameters always describe the same campaigns. Status is deliberately not accepted: the response already breaks every status out separately.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.summary.get
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
ListID	Integer	No	Only campaigns targeting this list
CreatedAfter	String	No	Only campaigns created at or after this point, parsed as in smscampaign.browse
CreatedBefore	String	No	Only campaigns created at or before this point, parsed as in smscampaign.browse

Response Fields:

Field	Type	Description
TotalCampaigns	Integer	Campaigns matching the filters
StatusCounts	Object	One key per status, including the statuses at zero, so a caller rendering a fixed set of buckets never has to guess
Totals	Object	TotalAudience, TotalSent, TotalDelivered, TotalUndelivered, TotalOptOuts, TotalClicks and TotalParts, summed across the selection
Costs	Array	One entry per currency, each with Currency, Campaigns, ActualCost and ConfirmedCost
CreatedAfter	String	The window's start as it was parsed, or null when none was sent
CreatedBefore	String	The window's end as it was parsed, or null when none was sent

Money is returned per currency and is never pre-summed. CostCurrency is a per-campaign column, so an account holding both USD and EUR campaigns has two totals and no single one; adding them would produce a figure in no currency at all. A caller showing a single spend figure should check that Costs holds exactly one entry.

Example Request

curl -X GET https://example.com/api/v1/smscampaign.summary.get \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.summary.get",
    "SessionID": "your-session-id",
    "CreatedAfter": "2026-08-01"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "TotalCampaigns": 16,
  "StatusCounts": {
    "Draft": 1,
    "Scheduled": 0,
    "Queueing": 0,
    "Sending": 1,
    "Paused": 0,
    "Cancelling": 0,
    "Sent": 12,
    "Cancelled": 2,
    "Failed": 0
  },
  "Totals": {
    "TotalAudience": 143840,
    "TotalSent": 138211,
    "TotalDelivered": 133902,
    "TotalUndelivered": 4309,
    "TotalOptOuts": 512,
    "TotalClicks": 18420,
    "TotalParts": 148903
  },
  "Costs": [
    { "Currency": "USD", "Campaigns": 15, "ActualCost": 2764.22, "ConfirmedCost": 2801.00 },
    { "Currency": "EUR", "Campaigns": 1, "ActualCost": 41.60, "ConfirmedCost": 41.60 }
  ],
  "CreatedAfter": "2026-08-01 00:00:00",
  "CreatedBefore": null
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "Invalid createdafter value. Expected YYYY-MM-DD or YYYY-MM-DD HH:MM:SS." }],
  "ErrorCode": 3
}

Error Codes

0: Success
2: The campaign summary could not be read
3: Invalid CreatedAfter or CreatedBefore value

Delete a Campaign

POST /api/v1/smscampaign.delete

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

A campaign in progress cannot be deleted; cancel it first. Deleting removes its queue rows, links and estimates with it.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.delete
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to delete

Example Request

curl -X POST https://example.com/api/v1/smscampaign.delete \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.delete",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821
  }'

Success Response

{ "Success": true, "ErrorCode": 0 }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "A campaign in progress cannot be deleted. Cancel it first." }],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing SMSCampaignID parameter
2: Campaign not found
3: A campaign in progress cannot be deleted; cancel it first
4: The campaign could not be deleted, so nothing was deleted
5: The campaign could not be deleted as a single transaction, so nothing was deleted

Duplicate a Campaign

POST /api/v1/smscampaign.copy

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 100 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

Copies any campaign you own into a new Draft named "Copy of" followed by the original name, whatever the original's status. Resending a finished campaign is the usual reason.

The copy keeps the audience (list, saved segment or conditions), the message and its tracked links, the sender, the gateway, the opt-out footer, link settings, timezone, quiet hours and send rate. It starts without the original's schedule and deadline, estimate, confirmed cost and statistics, so estimate it before sending.

The audience is checked again the way smscampaign.create checks it, so a campaign whose list was deleted or no longer has a mobile phone field cannot be duplicated. A gateway that is no longer available to your account does not stop the copy: it is made with no gateway, GatewayCleared is true, and you choose one with smscampaign.update before sending.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.copy
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
SMSCampaignID	Integer	Yes	The campaign to duplicate

Example Request

curl -X POST https://example.com/api/v1/smscampaign.copy \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.copy",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "SMSCampaignID": 4907,
  "SourceSMSCampaignID": 4821,
  "GatewayCleared": false,
  "Links": 1
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "The campaign cannot be duplicated because its audience is no longer valid: Invalid ListID." }],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: The campaign's audience is no longer valid (its list, segment or conditions)
4: The campaign's links could not be read, so nothing was duplicated
5: The campaign could not be duplicated, so nothing was created

Sending

Send a Campaign

POST /api/v1/smscampaign.send

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Starts sending immediately. Requires the EstimateID and ConfirmationToken from smscampaign.estimate.get, and stores the confirmed cost, recipient count and projected completion on the campaign. Nothing is recomputed here: the figures the sender approved are the figures that are stored.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.send
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to send. Must be in Draft
EstimateID	Integer	Yes	From smscampaign.estimate
ConfirmationToken	String	Yes	From smscampaign.estimate.get
SendDeadlineAt	String	No	YYYY-MM-DD HH:MM:SS. Stop sending after this moment even if recipients remain

Example Request

curl -X POST https://example.com/api/v1/smscampaign.send \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.send",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "EstimateID": 173,
    "ConfirmationToken": "1758377028.8f2c..."
  }'

Success Response

{ "Success": true, "ErrorCode": 0, "Status": "Queueing" }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 34, "Message": "The campaign changed after it was costed. Run the estimate again." }],
  "ErrorCode": 34
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
4: Missing or invalid EstimateID parameter; run smscampaign.estimate first
9: The campaign could not be sent, so nothing was sent
10: The campaign could not be sent as a single transaction, so nothing was sent
31: The cost estimate could not be read, so nothing was sent
32: Estimate not found for this campaign
33: The estimate has not finished; wait for it or run a new one
34: The campaign changed after it was costed; run the estimate again
35: The confirmation token is invalid or has expired
36: The estimate result is incomplete; run the estimate again

Schedule a Campaign

POST /api/v1/smscampaign.schedule

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

The same as sending, but at a future moment. The campaign sits in Scheduled until ScheduledAt passes, then moves to Queueing on its own. The confirmation token is required and expires on the same schedule, so schedule promptly after estimating.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.schedule
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to schedule. Must be in Draft
ScheduledAt	String	Yes	YYYY-MM-DD HH:MM:SS, in the campaign's timezone. Must be in the future
EstimateID	Integer	Yes	From smscampaign.estimate
ConfirmationToken	String	Yes	From smscampaign.estimate.get
SendDeadlineAt	String	No	Stop sending after this moment. Must be after ScheduledAt

Example Request

curl -X POST https://example.com/api/v1/smscampaign.schedule \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.schedule",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "ScheduledAt": "2026-10-01 09:00:00",
    "EstimateID": 173,
    "ConfirmationToken": "1758377028.8f2c..."
  }'

Success Response

{ "Success": true, "ErrorCode": 0, "Status": "Scheduled" }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 11, "Message": "Missing ScheduledAt parameter." }],
  "ErrorCode": 11
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
4: Missing or invalid EstimateID parameter; run smscampaign.estimate first
9: The campaign could not be scheduled, so nothing was scheduled
10: The campaign could not be scheduled as a single transaction
11: Missing ScheduledAt parameter
31-36: The estimate and token errors listed under smscampaign.send

Lifecycle

Pause a Campaign

POST /api/v1/smscampaign.pause

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Only a Queueing or Sending campaign can be paused. Pausing stops future releases; messages already handed to the gateway cannot be recalled. Pausing an already-paused campaign is a success rather than an error, because pause is the button people press twice.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.pause
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to pause

Example Request

curl -X POST https://example.com/api/v1/smscampaign.pause \
  -H "Content-Type: application/json" \
  -d '{ "Command": "smscampaign.pause", "SessionID": "your-session-id", "SMSCampaignID": 4821 }'

Success Response

{ "Success": true, "ErrorCode": 0, "Status": "Paused" }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "Only a campaign that is queueing or sending can be paused. This one is Draft." }],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: Only a queueing or sending campaign can be paused
4: The campaign changed status before it could be paused; read it again

Resume a Campaign

POST /api/v1/smscampaign.resume

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Returns a paused campaign to the status it was paused from. A campaign paused automatically because its queued cost drifted from the confirmed cost needs AcknowledgeCost=1, which is how the sender says they accept the new figure; the response carries the confirmed and drifted costs so they can see what they are accepting.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.resume
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to resume. Must be Paused
AcknowledgeCost	Integer	No	Pass 1 to resume a campaign paused on cost drift

Example Request

curl -X POST https://example.com/api/v1/smscampaign.resume \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.resume",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "AcknowledgeCost": 1
  }'

Success Response

{ "Success": true, "ErrorCode": 0, "Status": "Sending" }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 4, "Message": "This campaign was paused because its queued cost drifted from the confirmed cost. Pass AcknowledgeCost=1 to resume it anyway." }],
  "ErrorCode": 4,
  "ConfirmedCost": "12.50000",
  "ConfirmedRecipients": 250,
  "CostCurrency": "USD",
  "CostDriftTolerance": 0.05
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: Only a Paused campaign can be resumed
4: Paused on cost drift; pass AcknowledgeCost=1 to resume anyway
5: The campaign changed status before it could be resumed; read it again

Cancel a Campaign

POST /api/v1/smscampaign.cancel

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Cancelling returns immediately and does not wait for the send to wind down. A Draft campaign goes straight to Cancelled; anything already in flight passes through Cancelling so the workers can stop cleanly, and its queue rows are still present for a short time afterwards. Cancellation is final: a cancelled campaign cannot be resumed.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.cancel
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign to cancel

Example Request

curl -X POST https://example.com/api/v1/smscampaign.cancel \
  -H "Content-Type: application/json" \
  -d '{ "Command": "smscampaign.cancel", "SessionID": "your-session-id", "SMSCampaignID": 4821 }'

Success Response

{ "Success": true, "ErrorCode": 0, "Status": "Cancelling" }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "This campaign has already finished. It is Sent." }],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: The campaign has already finished
4: The campaign changed status before it could be cancelled; read it again

Cost estimation

Why the estimate is a job rather than an answer

Measuring a campaign means resolving its audience, removing suppressed, invalid and duplicate numbers, personalizing every message and counting the parts each one will take. For a one-million recipient audience that cannot finish inside a single request, so smscampaign.estimate queues the work and returns an id. Poll smscampaign.estimate.get until it reports Done, then pass the EstimateID and ConfirmationToken it returns to smscampaign.send or smscampaign.schedule.

The token is what proves the cost was seen before the campaign was sent. It is signed over the estimate, the campaign and the campaign's content, so editing the campaign after estimating it invalidates the token and the estimate has to be run again. It also expires, after SMS_CAMPAIGN_ESTIMATE_TOKEN_TTL seconds (900 by default).

Cost is message parts multiplied by the configured cost per part. No SMS gateway exposes its pricing to the platform, so this is an estimate for planning, not a billing figure.

Start a Campaign Cost Estimate

POST /api/v1/smscampaign.estimate

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Only a campaign still in Draft can be estimated. Requesting an estimate for a campaign that already has an unfinished job for the same content returns that job instead of queueing a second one, so polling clients and double-clicked buttons do not cause the same audience to be measured twice.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.estimate
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
SMSCampaignID	Integer	Yes	The campaign to estimate. Must belong to the authenticated user and be in Draft

Example Request

curl -X POST https://example.com/api/v1/smscampaign.estimate \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.estimate",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "EstimateID": 173,
  "Status": "Pending",
  "Reused": false
}

Error Response

{
  "Success": false,
  "Errors": [
    {
      "Code": 3,
      "Message": "Only a draft campaign can be estimated. This one is Sending."
    }
  ],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Campaign not found
3: The campaign is not a draft, so it cannot be estimated
4: The list could not be read; retry
5: The list has no mobile phone number field, so it cannot receive SMS
6: The estimate could not be started; retry

Reused is true when an unfinished job for this campaign and this exact content already existed and was returned instead of a new one.

Read a Campaign Cost Estimate

GET /api/v1/smscampaign.estimate

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage, including for this read: the confirmation token it returns is what authorizes a spend, so it is not a SMSCampaigns.Get capability
• Legacy endpoint access via /api.php is also supported (command smscampaign.estimate.get)

Poll this until Status is Done or Failed. A ConfirmationToken is returned only when the estimate is Done and the campaign still matches the one that was costed.

"Still matches" is decided on the campaign's content, not only on its modification time. The estimate records a fingerprint of the audience, message, footer and gateway it measured, and that is compared with the campaign as it stands now. A modification time alone would not be enough: it has one second of resolution, so an edit landing in the same second as the measurement would leave the timestamp unchanged while the content it describes had moved on. When the two disagree the response carries Stale: true and a StaleReason, and no token, so run the estimate again.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.estimate.get
SessionID	String	No	Session ID obtained from login
APIKey	String	No	API key for authentication
SMSCampaignID	Integer	Yes	The campaign the estimate belongs to
EstimateID	Integer	Yes	The id returned by smscampaign.estimate

Example Request

curl -X GET https://example.com/api/v1/smscampaign.estimate \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.estimate.get",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "EstimateID": 173
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "EstimateID": 173,
  "SMSCampaignID": 4821,
  "Status": "Done",
  "CreatedAt": "2026-09-20 14:02:11",
  "CompletedAt": "2026-09-20 14:03:48",
  "Result": {
    "Audience": 412903,
    "Invalid": 1184,
    "Duplicate": 2071,
    "Suppressed": 9330,
    "TooLong": 0,
    "Sendable": 400318,
    "TotalParts": 431566,
    "Encodings": {
      "GSM7": 388201,
      "UCS2": 12117
    },
    "ProjectedCost": 4315.66,
    "CostCurrency": "USD",
    "CostPerPart": 0.01,
    "ProjectedCompletionAt": "2026-09-22 09:15:00",
    "MeasuredAt": "2026-09-20 14:03:48",
    "CampaignFingerprint": "6b1e...c04a"
  },
  "Stale": false,
  "ConfirmationToken": "1758377028.8f2c...",
  "ConfirmationTokenExpiresInSeconds": 900
}

Error Response

{
  "Success": false,
  "Errors": [
    {
      "Code": 5,
      "Message": "Estimate not found for this campaign."
    }
  ],
  "ErrorCode": 5
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Missing or invalid EstimateID parameter
3: Campaign not found
4: The estimate could not be read; retry
5: Estimate not found for this campaign
6: The estimate finished but its result cannot be read; run it again

Response fields

Field	Meaning
Status	Pending, Running, Done or Failed
Error	Present only when Status is Failed, explaining why
Result	Present only when Status is Done
Stale	true when the campaign changed after it was costed. No token is issued and the estimate has to be run again
ConfirmationToken	Present only when Status is Done and Stale is false

The funnel in Result

Field	Meaning
Audience	Subscribers matching the campaign's list and segment with a phone number present
Invalid	Numbers that could not be normalized to a sendable form
Duplicate	Numbers appearing more than once, counted once as sendable and the rest here
Suppressed	Numbers suppressed at system, user, list or gateway scope
TooLong	Messages needing more parts than the gateway will concatenate
Sendable	What will actually be sent. This is the number the cost is based on
TotalParts	Message parts across every sendable recipient
Encodings	Sendable recipients by message encoding, GSM7 and UCS2
ProjectedCost	TotalParts multiplied by CostPerPart
ProjectedCompletionAt	When the campaign would finish at the account's current send-rate limits. null when there is nothing to project from, which includes an account with no configured limit and a send-rate counter that could not be read: an unknown schedule is reported as unknown rather than as immediate
CampaignFingerprint	A fingerprint of the campaign content that was measured. Used to decide staleness; see below

Test and direct sends

Send a Test Message

POST /api/v1/smscampaign.test

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 60 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

Sends one copy of a campaign's message to one number, using the campaign's gateway and links. It counts against the account's SMS send limits like any other message.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smscampaign.test
SessionID	String	No	Session ID obtained from login
SMSCampaignID	Integer	Yes	The campaign whose message to test
RecipientNumber	String	Yes	The destination number
SenderID	String	No	Override the campaign's sender id

Example Request

curl -X POST https://example.com/api/v1/smscampaign.test \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smscampaign.test",
    "SessionID": "your-session-id",
    "SMSCampaignID": 4821,
    "RecipientNumber": "+15550100001"
  }'

Success Response

{ "Success": true, "ErrorCode": 0 }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 4, "Message": "This campaign has no SMS gateway. Set GatewayID with smscampaign.update first." }],
  "ErrorCode": 4
}

Error Codes

0: Success
1: Missing or invalid SMSCampaignID parameter
2: Missing RecipientNumber parameter
3: Campaign not found
4: The campaign has no SMS gateway
5: The campaign's gateway is no longer active or assigned to this account
7: The campaign's links could not be read, so nothing was sent
8: The campaign has no message content to test
9: The test message is too long for the gateway's concatenation limit
10: SMS rate limit exceeded for an interval
11: The test message could not be queued, so nothing was sent
12: The message's merge tags could not be rendered, so nothing was sent
13: The message has a merge tag that cannot be read, which would be sent as typed

Send a Single Message

POST /api/v1/sms.send

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Rate limit: 300 requests per 60 seconds
• Legacy endpoint access via /api.php is also supported

One message to one number, with no campaign involved. ListID and SubscriberID are optional and must be given together: supplying them attributes the message to that contact, so it appears in their SMS history.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: sms.send
SessionID	String	No	Session ID obtained from login
RecipientNumber	String	Yes	The destination number
MessageContent	String	Yes	The message body
GatewayID	Integer	Yes	The gateway to send through. sms.gateways.get lists the available ones
SenderID	String	No	The sender number or alphanumeric id
ListID	Integer	No	Attribute the message to a contact. Must be sent with SubscriberID
SubscriberID	Integer	No	The contact on that list. Must be sent with ListID

Example Request

curl -X POST https://example.com/api/v1/sms.send \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "sms.send",
    "SessionID": "your-session-id",
    "RecipientNumber": "+15550100001",
    "MessageContent": "Your code is 4821.",
    "GatewayID": 3
  }'

Success Response

{ "Success": true, "ErrorCode": 0 }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 6, "Message": "ListID and SubscriberID must be sent together, or not at all." }],
  "ErrorCode": 6
}

Error Codes

0: Success
1: Missing RecipientNumber parameter
2: Missing MessageContent parameter
3: Missing or invalid GatewayID parameter
4: Invalid GatewayID, or the gateway is not available to this account
6: ListID and SubscriberID must be sent together, or not at all
7: Invalid ListID
8: The subscriber could not be read, so nothing was sent
9: That subscriber is not on that list
10: The message is too long for the gateway's concatenation limit
11: SMS rate limit exceeded for an interval
12: The message could not be queued, so nothing was sent

Message templates

A saved message body that can be reused when composing a campaign. Templates are per account: one account can never read, change or delete another's.

Create a Template

POST /api/v1/smstemplate.create

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Manage
• Legacy endpoint access via /api.php is also supported

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: smstemplate.create
SessionID	String	No	Session ID obtained from login
TemplateName	String	Yes	A name, up to 255 characters
MessageContent	String	No	The body. May be empty, so a name can be saved to fill in later

Example Request

curl -X POST https://example.com/api/v1/smstemplate.create \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smstemplate.create",
    "SessionID": "your-session-id",
    "TemplateName": "Weekly promo",
    "MessageContent": "Hi {FirstName}, this week only."
  }'

Success Response

{ "Success": true, "ErrorCode": 0, "TemplateID": 17 }

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 1, "Message": "Missing TemplateName parameter" }],
  "ErrorCode": 1
}

Error Codes

0: Success
1: Missing or invalid TemplateName parameter, including a non-string value
2: TemplateName is longer than 255 characters
3: The template could not be created
4: MessageContent must be a string

Read, List, Update and Delete Templates

smstemplate.get returns one template, smstemplate.browse lists them, smstemplate.update changes a name or body, and smstemplate.delete removes one. They share their parameters and error codes, so they are documented together.

GET /api/v1/smstemplate.get · GET /api/v1/smstemplate.browsePOST /api/v1/smstemplate.update · POST /api/v1/smstemplate.delete

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get for get and browse, SMSCampaigns.Manage for update and delete
• Legacy endpoint access via /api.php is also supported

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	One of smstemplate.get, smstemplate.browse, smstemplate.update or smstemplate.delete
SessionID	String	No	Session ID obtained from login
TemplateID	Integer	Yes	For get, update and delete. Must belong to the caller
TemplateName	String	No	For update
MessageContent	String	No	For update. Pass at least one of the two
Search	String	No	For browse. Matches the start of a template name
RecordsPerRequest	Integer	No	For browse. Default 25, clamped to 200
RecordsFrom	Integer	No	For browse. Offset, default 0

Example Request

curl -X GET https://example.com/api/v1/smstemplate.browse \
  -H "Content-Type: application/json" \
  -d '{
    "Command": "smstemplate.browse",
    "SessionID": "your-session-id",
    "Search": "Weekly"
  }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "Templates": [
    {
      "TemplateID": 17,
      "TemplateName": "Weekly promo",
      "MessageContent": "Hi {FirstName}, this week only.",
      "CreatedAt": "2026-09-20 14:02:11",
      "UpdatedAt": "2026-09-20 14:02:11"
    }
  ],
  "TotalTemplates": 1
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 3, "Message": "Template not found." }],
  "ErrorCode": 3
}

Error Codes

0: Success
1: Missing or invalid TemplateID parameter (get, update, delete); read failure (browse)
2: The template could not be read (get, update, delete); Search must be a string (browse)
3: Template not found, including a template belonging to another account
4: TemplateName cannot be empty (update)
5: TemplateName is longer than 255 characters (update)
6: Nothing to update; pass TemplateName, MessageContent or both
7: The template could not be updated
8: MessageContent must be a string (update)
9: TemplateName must be a string (update)

Asking for a template that belongs to another account answers Template not found rather than a permission error, and deleting one reports the same. There is no response that distinguishes "exists but is not yours" from "does not exist", so template ids cannot be probed.

Every parameter that is expected to be a string is rejected when it is not one, rather than being coerced. api.php accepts nested structures, so a value can arrive as an array, and casting one to a string yields the literal Array: an endpoint that cast before validating would store a template named Array. "Empty" and "not a string" are separate codes on update, because they call for different corrections.

Supporting endpoints

Get Available SMS Gateways

GET /api/v1/sms.gateways.get

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get
• Legacy endpoint access via /api.php is also supported

The gateways this account may send through, with the capabilities a composer needs: how many parts each will concatenate, and which sender ids are available.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: sms.gateways.get
SessionID	String	No	Session ID obtained from login

Example Request

curl -X GET https://example.com/api/v1/sms.gateways.get \
  -H "Content-Type: application/json" \
  -d '{ "Command": "sms.gateways.get", "SessionID": "your-session-id" }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "Gateways": [
    {
      "GatewayID": 3,
      "GatewayName": "Primary",
      "MessageConcatenation": 5,
      "SenderNumbers": ["+15550100000", "ACME"]
    }
  ]
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 1, "Message": "The gateway list could not be read." }],
  "ErrorCode": 1
}

Error Codes

0: Success
1: The gateway list could not be read

Get Merge Tags for a List

GET /api/v1/sms.mergetags.get

API Usage Notes

• Authentication required: User API Key
• Required permissions: SMSCampaigns.Get
• Legacy endpoint access via /api.php is also supported

The merge tags a message for this list may use: its custom fields by merge tag alias (or CustomField<ID> when a field has none), its global custom fields, then the standard subscriber fields. Every tag is measured at its rendered length when the message is costed, so the parts reported by the estimate are the parts that will be sent.

SMS merge tags use the email syntax and are rendered as plain text, never HTML-encoded:

• {{ Subscriber:FirstName }} is the recipient's value, or nothing when it is empty.
• {{ Subscriber:FirstName | "there" }} falls back to the quoted text when the value is empty.
• Email helpers work, for example {{ uppercase Subscriber:FirstName }} or {{ truncate-10 Subscriber:City }}, and so do {{ List:... }} and {{ User:... }}.
• {{ Subscriber:EmailAddress }} is empty for a contact without an email address and for an SMS-only contact, whose placeholder address is never sent.

In a test send there is no recipient, so every subscriber tag renders its fallback.

Request Body Parameters:

Parameter	Type	Required	Description
Command	String	Yes	API command: sms.mergetags.get
SessionID	String	No	Session ID obtained from login
ListID	Integer	Yes	The list whose fields to return

Example Request

curl -X GET https://example.com/api/v1/sms.mergetags.get \
  -H "Content-Type: application/json" \
  -d '{ "Command": "sms.mergetags.get", "SessionID": "your-session-id", "ListID": 42 }'

Success Response

{
  "Success": true,
  "ErrorCode": 0,
  "MergeTags": [
    { "Tag": "{{ Subscriber:FirstName }}", "Field": "FirstName", "FieldName": "First name", "Group": "Custom", "CustomFieldID": 7, "IsPhoneField": false },
    { "Tag": "{{ Subscriber:CustomField12 }}", "Field": "CustomField12", "FieldName": "Mobile number", "Group": "Custom", "CustomFieldID": 12, "IsPhoneField": true },
    { "Tag": "{{ Subscriber:Tier }}", "Field": "Tier", "FieldName": "Loyalty tier", "Group": "Global", "CustomFieldID": 30, "IsPhoneField": false },
    { "Tag": "{{ Subscriber:EmailAddress }}", "Field": "EmailAddress", "FieldName": "Email address", "Group": "Standard", "CustomFieldID": null, "IsPhoneField": false }
  ],
  "PhoneFieldID": 12,
  "SupportsDefaultValueSyntax": true,
  "DefaultValueExample": "{{ Subscriber:FirstName | \"there\" }}"
}

Error Response

{
  "Success": false,
  "Errors": [{ "Code": 2, "Message": "Invalid ListID." }],
  "ErrorCode": 2
}

Error Codes

0: Success
1: Missing ListID parameter
2: Invalid ListID
3: The list's SMS settings could not be read
4: The list's fields could not be read