---
title: PATCH /tasks/{task_id}/custom-fields/{custom_field_id}
slug: content-marketing-platform/api/patch-taskstaskidcustom-fieldscustomfieldid
docTags:
createdAt: 2026-10-01T18:51:26.265Z
---
{
"id": "612u_-5R1E-ziovkB9IUx",
"type": "api-oas-v2",
"data": {
"method": "PATCH",
"url": "https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id}",
"servers": [
{
"url": "https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id}",
"description": "v3 version of Optimizely CMP Open API"
}
],
"name": "PATCH /tasks/{task_id}/custom-fields/{custom_field_id}",
"description": "Update a custom field of a task.\nYou can update the following types: text_field, multi_line_text_field, checkboxes, dropdown, multi_select_dropdown, multiple_choice, date_field, rich_text_field
",
"contentType": "application/json",
"request": {
"pathParameters": [
{
"kind": "required",
"name": "task_id",
"type": "string",
"example": "5f857f30e1c4a2038d6179e9",
"description": "Unique identifier of the task"
},
{
"kind": "required",
"name": "custom_field_id",
"type": "string",
"example": "9nu8ue9wf8u9nusd9q",
"description": "Unique identifier of the custom field"
}
],
"headerParameters": [
{
"name": "accept",
"type": "string",
"kind": "optional",
"description": "Generated from available response content types",
"enum": [
"application/json"
],
"default": "application/json"
}
],
"queryParameters": [],
"bodyDataParameters": [
{
"kind": "required",
"name": "body",
"type": "object",
"description": "Payload to update the custom field.\n",
"customType": "TaskCustomFieldUpdateRequest",
"schema": [
{
"name": "values",
"kind": "required",
"type": "array",
"description": "An array of choice IDs, if the custom field has choices. Otherwise, text values to update the custom field values with. Must contain at least one id/value in the array. For custom fields of type checkboxes, you can provide an array of multiple-choice IDs as values.\nValue for the custom field of type date_field must follow this format: YYYY-MM-DD.
",
"example": "",
"itemType": "string",
"customType": "string[]",
"itemExample": "1nu8ue9wf8u9nusd9u",
"itemDefault": ""
}
],
"modelRef": "#/components/schemas/TaskCustomFieldUpdateRequest",
"isExpanded": true
}
],
"formDataParameters": [],
"oAuthParameters": [
{
"id": "OAuth2",
"name": "OAuth2",
"kind": "optional",
"type": "oauth2",
"oauth2Flows": {
"clientCredentials": {
"tokenUrl": "https://accounts.cmp.optimizely.com/o/oauth2/v1/token",
"scopes": {}
},
"authorizationCode": {
"authorizationUrl": "https://accounts.cmp.optimizely.com/o/oauth2/v1/auth",
"tokenUrl": "https://accounts.cmp.optimizely.com/o/oauth2/v1/token",
"scopes": {
"openid": "Grants the ability to receive a unique identifier for the user.",
"profile": "Grants access to user profile information.",
"offline_access": "Grants the ability to refresh access_token using the refresh token even when user is not present (not logged in)."
}
}
},
"requiredScopes": [
"openid",
"profile",
"offline_access"
]
}
],
"cookieParameters": []
},
"responses": [
{
"statusCode": "200",
"description": "Updated custom field",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"description": "",
"customType": "TaskCustomField",
"schema": [
{
"name": "id",
"kind": "required",
"type": "string",
"description": "Unique identifier for the custom field",
"example": "9nu8ue9wf8u9nusd9q"
},
{
"name": "name",
"kind": "required",
"type": "string",
"description": "Name of the custom field",
"example": "My Dropdown"
},
{
"name": "type",
"kind": "required",
"type": "string",
"description": "Type of the custom field",
"example": "dropdown",
"enum": [
"text_field",
"multi_line_text_field",
"checkboxes",
"dropdown",
"multi_select_dropdown",
"multiple_choice",
"date_field",
"image",
"video",
"rich_text_field"
]
},
{
"name": "values",
"kind": "required",
"type": "array",
"description": "List of values of the custom field",
"example": "",
"itemType": "object",
"customType": "object[]",
"schema": [
{
"name": "id",
"kind": "required",
"type": "string",
"nullable": true,
"description": "Identifier of the custom field value",
"example": "1nu8ue9wf8u9nusd9u"
},
{
"name": "name",
"kind": "required",
"type": "string",
"description": "Name of the custom field value",
"example": "Some text"
}
]
},
{
"name": "links",
"kind": "required",
"type": "object",
"description": "Meta links",
"example": "",
"schema": [
{
"name": "self",
"kind": "required",
"type": "string",
"description": "URL of the custom field",
"example": "https://api.cmp.optimizely.com/v3/tasks/5f857f30e1c4a2038d6179e9/custom-fields/9nu8ue9wf8u9nusd9q"
},
{
"name": "choices",
"kind": "required",
"type": "string",
"nullable": true,
"description": "URL of the available custom field choices",
"example": "https://api.cmp.optimizely.com/v3/tasks/5f857f30e1c4a2038d6179e9/custom-fields/9nu8ue9wf8u9nusd9q/choices"
}
]
}
],
"modelRef": "#/components/schemas/TaskCustomField",
"isExpanded": true
}
]
},
{
"statusCode": "400",
"description": "Client error",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"example": "{\"message\":\"Unsupported arguments: a,b,c\"}",
"description": "Error payload",
"customType": "Error",
"schema": [
{
"name": "message",
"kind": "required",
"type": "string",
"description": "Message describing the error",
"example": "Not found"
},
{
"name": "errors",
"kind": "optional",
"type": "map",
"description": "Additional information",
"example": "",
"customType": "map",
"schema": []
}
],
"modelRef": "#/components/schemas/Error",
"isExpanded": true
}
]
},
{
"statusCode": "401",
"description": "Authorization error",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"example": "{\"message\":\"Unauthorized\"}",
"description": "Error payload",
"customType": "Error",
"schema": [
{
"name": "message",
"kind": "required",
"type": "string",
"description": "Message describing the error",
"example": "Not found"
},
{
"name": "errors",
"kind": "optional",
"type": "map",
"description": "Additional information",
"example": "",
"customType": "map",
"schema": []
}
],
"modelRef": "#/components/schemas/Error",
"isExpanded": true
}
]
},
{
"statusCode": "403",
"description": "Permission error",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"example": "{\"message\":\"You do not have the permission to perform this operation\"}",
"description": "Error payload",
"customType": "Error",
"schema": [
{
"name": "message",
"kind": "required",
"type": "string",
"description": "Message describing the error",
"example": "Not found"
},
{
"name": "errors",
"kind": "optional",
"type": "map",
"description": "Additional information",
"example": "",
"customType": "map",
"schema": []
}
],
"modelRef": "#/components/schemas/Error",
"isExpanded": true
}
]
},
{
"statusCode": "404",
"description": "Not found error",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"example": "{\"message\":\"Resource not found\"}",
"description": "Error payload",
"customType": "Error",
"schema": [
{
"name": "message",
"kind": "required",
"type": "string",
"description": "Message describing the error",
"example": "Not found"
},
{
"name": "errors",
"kind": "optional",
"type": "map",
"description": "Additional information",
"example": "",
"customType": "map",
"schema": []
}
],
"modelRef": "#/components/schemas/Error",
"isExpanded": true
}
]
},
{
"statusCode": "422",
"description": "Unprocessable entity error",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"example": "{\"message\":\"Resource cannot be processed\"}",
"description": "Error payload",
"customType": "Error",
"schema": [
{
"name": "message",
"kind": "required",
"type": "string",
"description": "Message describing the error",
"example": "Not found"
},
{
"name": "errors",
"kind": "optional",
"type": "map",
"description": "Additional information",
"example": "",
"customType": "map",
"schema": []
}
],
"modelRef": "#/components/schemas/Error",
"isExpanded": true
}
]
}
],
"hasXCodeSamples": false,
"examples": {
"languages": [
{
"id": "mB8eeAE_O2n6BuT74YN-H",
"language": "curl",
"label": "cURL",
"code": "curl --request PATCH \\\n --url https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id} \\\n --header 'accept: application/json' \\\n --header 'content-type: application/json' \\\n --data '{\n \"values\": []\n }'"
},
{
"id": "g9zu5Et1IqhUBDnGuTuPg",
"language": "javascript",
"label": "javascript",
"code": "var myHeaders = new Headers();\nmyHeaders.append(\"accept\", \"application/json\");\nmyHeaders.append(\"content-type\", \"application/json\");\n\nvar raw = JSON.stringify({\n \"values\": []\n});\n\nvar requestOptions = {\n method: 'PATCH',\n headers: myHeaders,\n body: raw,\n redirect: 'follow'\n};\n\nfetch(\"https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id}\", requestOptions)\n .then(response => response.text())\n .then(result => console.log(result))\n .catch(error => console.log('error', error));"
},
{
"id": "orUCSrGss8CpS9XMNge8d",
"language": "ruby",
"label": "Ruby",
"code": "require \"uri\"\nrequire \"json\"\nrequire \"net/http\"\n\nurl = URI(\"https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id}\")\n\nhttps = Net::HTTP.new(url.host, url.port)\nhttps.use_ssl = true\n\nrequest = Net::HTTP::Patch.new(url)\nrequest[\"accept\"] = \"application/json\"\nrequest[\"content-type\"] = \"application/json\"\nrequest.body = JSON.dump({\n \"values\": []\n})\n\nresponse = https.request(request)\nputs response.read_body\n"
},
{
"id": "9iPgBCletwFqwS-kySVwo",
"language": "python",
"label": "Python",
"code": "import requests\nimport json\n\nurl = \"https://api.cmp.optimizely.com/v3/tasks/{task_id}/custom-fields/{custom_field_id}\"\n\npayload = json.dumps({\n \"values\": []\n})\nheaders = {\n 'accept': 'application/json',\n 'content-type': 'application/json'\n}\n\nresponse = requests.request(\"PATCH\", url, headers=headers, data=payload)\n\nprint(response.text)\n"
}
],
"selectedLanguageId": "mB8eeAE_O2n6BuT74YN-H"
},
"results": {
"languages": [
{
"id": "response-0-200",
"language": "200",
"code": "// Updated custom field\n{\n \"id\": \"9nu8ue9wf8u9nusd9q\",\n \"name\": \"My Dropdown\",\n \"type\": \"dropdown\",\n \"values\": [\n {\n \"id\": \"1nu8ue9wf8u9nusd9u\",\n \"name\": \"Some text\"\n }\n ],\n \"links\": {\n \"self\": \"https://api.cmp.optimizely.com/v3/tasks/5f857f30e1c4a2038d6179e9/custom-fields/9nu8ue9wf8u9nusd9q\",\n \"choices\": \"https://api.cmp.optimizely.com/v3/tasks/5f857f30e1c4a2038d6179e9/custom-fields/9nu8ue9wf8u9nusd9q/choices\"\n }\n}"
},
{
"id": "response-1-400",
"language": "400",
"code": "// Client error\n{\n \"message\": \"Not found\",\n \"errors\": \"\"\n}"
},
{
"id": "response-2-401",
"language": "401",
"code": "// Authorization error\n{\n \"message\": \"Not found\",\n \"errors\": \"\"\n}"
},
{
"id": "response-3-403",
"language": "403",
"code": "// Permission error\n{\n \"message\": \"Not found\",\n \"errors\": \"\"\n}"
},
{
"id": "response-4-404",
"language": "404",
"code": "// Not found error\n{\n \"message\": \"Not found\",\n \"errors\": \"\"\n}"
},
{
"id": "response-5-422",
"language": "422",
"code": "// Unprocessable entity error\n{\n \"message\": \"Not found\",\n \"errors\": \"\"\n}"
}
],
"selectedLanguageId": "response-0-200"
}
},
"children": [
{
"text": ""
}
]
}