---
title: PATCH /milestones/{id}
slug: content-marketing-platform/api/patch-milestonesid
docTags:
createdAt: 2026-10-01T18:51:26.265Z
---
{
"id": "eHqryPlSyA8Bt4pg_vs2W",
"type": "api-oas-v2",
"data": {
"method": "PATCH",
"url": "https://api.cmp.optimizely.com/v3/milestones/{id}",
"servers": [
{
"url": "https://api.cmp.optimizely.com/v3/milestones/{id}",
"description": "v3 version of Optimizely CMP Open API"
}
],
"name": "PATCH /milestones/{id}",
"description": "Experimental Updates a milestone. All fields are optional. Only provided fields will be updated. Note: If tasks array is empty, it will remove all task associations for that milestone.
",
"contentType": "application/json",
"request": {
"pathParameters": [
{
"kind": "required",
"name": "id",
"type": "string",
"example": "63f1c2b675be4132854d2741",
"description": "Unique identifier of the milestone"
}
],
"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 a milestone",
"customType": "MilestoneUpdateRequest",
"schema": [
{
"name": "title",
"kind": "optional",
"type": "string",
"nullable": false,
"description": "Title of the milestone. This should be between 1 and 80 characters.",
"example": "Q1 Product Launch",
"minLength": 1,
"maxLength": 80
},
{
"name": "description",
"kind": "optional",
"type": "string",
"nullable": true,
"description": "Description of the milestone. If provided, this should be between 1 and 250 characters.
",
"example": "Complete all tasks for the Q1 product launch",
"minLength": 1,
"maxLength": 250
},
{
"name": "campaign_id",
"kind": "optional",
"type": "string",
"nullable": false,
"description": "Id of the campaign to be associated with the milestone",
"example": "63f1c2b675be4132854d2741"
},
{
"name": "due_date",
"kind": "optional",
"type": "string",
"nullable": false,
"description": "Date and time on which the milestone will expire, in ISO 8601 UTC format
",
"example": "2023-10-07T13:15:30Z",
"format": "date-time"
},
{
"name": "hex_color",
"kind": "optional",
"type": "string",
"nullable": false,
"description": "Hex color code for the milestone label",
"example": "#4ECFD5"
},
{
"name": "tasks",
"kind": "optional",
"type": "array",
"nullable": false,
"description": "List of tasks to be associated with the milestone. This can be an empty array, but in that case it will remove all task associations for that milestone.
",
"example": "[{\"id\":\"63f1c2b675be4132854d2741\"},{\"id\":\"63f1c2b675be4132854d2742\"}]",
"itemType": "object",
"customType": "object[]",
"schema": [
{
"name": "id",
"kind": "required",
"type": "string",
"description": "Task ID"
}
]
}
],
"modelRef": "#/components/schemas/MilestoneUpdateRequest",
"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 milestone",
"jsonExample": "",
"isExpanded": true,
"schema": [
{
"kind": "optional",
"type": "object",
"description": "",
"customType": "MilestoneResponse",
"schema": [
{
"name": "id",
"kind": "required",
"type": "string",
"description": "Unique identifier of the milestone",
"example": "63f1c2b675be4132854d2741"
},
{
"name": "title",
"kind": "required",
"type": "string",
"description": "Title of the milestone",
"example": "Sample Milestone"
},
{
"name": "color",
"kind": "required",
"type": "string",
"description": "Color of the milestone label",
"example": "#4ECFD5"
},
{
"name": "description",
"kind": "required",
"type": "string",
"nullable": true,
"description": "Description of the milestone",
"example": "This is a milestone"
},
{
"name": "due_date",
"kind": "required",
"type": "string",
"description": "Date and time on which the milestone will expire, in ISO 8601 UTC format
",
"example": "2023-10-07T13:15:30Z",
"format": "date-time"
},
{
"name": "campaign",
"kind": "required",
"type": "object",
"nullable": true,
"description": "Campaign associated with the milestone",
"example": "",
"schema": [
{
"name": "id",
"kind": "required",
"type": "string",
"description": "Unique identifier of the campaign",
"example": "63f1c2b675be4132854d2742"
}
]
},
{
"name": "links",
"kind": "required",
"type": "object",
"description": "Meta links",
"example": "",
"schema": [
{
"name": "self",
"kind": "required",
"type": "string",
"description": "URL of the milestone",
"example": "https://api.cmp.optimizely.com/v3/milestones/63f1c2b675be4132854d2741"
}
]
}
],
"modelRef": "#/components/schemas/MilestoneResponse",
"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": "NjgFFUXoqb4DCLANWqU9N",
"language": "curl",
"label": "cURL",
"code": "curl --request PATCH \\\n --url https://api.cmp.optimizely.com/v3/milestones/{id} \\\n --header 'accept: application/json' \\\n --header 'content-type: application/json' \\\n --data '{\n \"tasks\": [\n {\n \"id\": \"\"\n }\n ]\n }'"
},
{
"id": "Uock4lsfLXZsj6bB19JIX",
"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 \"tasks\": [\n {\n \"id\": \"\"\n }\n ]\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/milestones/{id}\", requestOptions)\n .then(response => response.text())\n .then(result => console.log(result))\n .catch(error => console.log('error', error));"
},
{
"id": "JGbP4rgJyXpDtCr11QAtF",
"language": "ruby",
"label": "Ruby",
"code": "require \"uri\"\nrequire \"json\"\nrequire \"net/http\"\n\nurl = URI(\"https://api.cmp.optimizely.com/v3/milestones/{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 \"tasks\": [\n {\n \"id\": \"\"\n }\n ]\n})\n\nresponse = https.request(request)\nputs response.read_body\n"
},
{
"id": "gzgl8U-UNHxzsgQGIl3uS",
"language": "python",
"label": "Python",
"code": "import requests\nimport json\n\nurl = \"https://api.cmp.optimizely.com/v3/milestones/{id}\"\n\npayload = json.dumps({\n \"tasks\": [\n {\n \"id\": \"\"\n }\n ]\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": "NjgFFUXoqb4DCLANWqU9N"
},
"results": {
"languages": [
{
"id": "response-0-200",
"language": "200",
"code": "// Updated milestone\n{\n \"id\": \"63f1c2b675be4132854d2741\",\n \"title\": \"Sample Milestone\",\n \"color\": \"#4ECFD5\",\n \"description\": \"This is a milestone\",\n \"due_date\": \"2023-10-07T13:15:30Z\",\n \"campaign\": {\n \"id\": \"63f1c2b675be4132854d2742\"\n },\n \"links\": {\n \"self\": \"https://api.cmp.optimizely.com/v3/milestones/63f1c2b675be4132854d2741\"\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": ""
}
]
}