Theme preview comments

Reply to a preview comment

Appends a reply. Authorship comes from the authenticated principal. Idempotent on the reply’s client_id: repeating a request appends nothing and succeeds.

Set author_kind to agent to record the agent’s answer instead of a person’s. A reply bound to the active run moves it from handed to review, and leaves every other status where a person put it: the agent can answer a thread but never close it, and never reopens one somebody decided. Reopening or skipping a thread revokes its run; later replies carrying that identity receive 409. While the run remains authorized, repeating its answer stores nothing and succeeds, so the same body cannot arrive twice under two ids.

An agent reply can be a question instead. With unfinished true the reply is Mist saying it could not make the change without the author’s answer, and a reply bound to the active run moves the thread from handed to needs_info rather than review, handing it back to the person who sent it. The author answers by reopening the thread and sending it to Mist again. unfinished needs an agent reply with a run_id; anywhere else it receives 422.

An agent reply bound to a run (run_id given) must come from the person who started that run, the one who sent the comment to Mist. From anyone else it receives 409 and stores nothing. A run started before the starter was recorded accepts any authorized caller, as it did before.

An agent reply is recorded with the person who posted it, in the reply’s posted_by. An agent reply with no run_id needs a person behind the request: a token with no person, such as a company or app token, receives 403 and stores nothing. It is posted by that person’s own chat, and the same text from two people is two replies, while one person repeating it is one. A reply bound to a run is the run’s, so a token with no person may post it only to a run started before its starter was recorded, and has no posted_by.

Replying is discussion and is never refused for belonging to work. When the thread belongs to a work item, though, the run that owns the thread is the work item’s and not the comment’s: an answer carrying any other identity receives 409, and an answer that does land leaves the thread where it is, because a linked thread’s status belongs to the work item.

POST

api

v202604

themes

{theme_id}

preview_comments

{client_id}

replies

Reply to a preview comment

curl --request POST \
  --url https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data @- <<EOF
{
  "reply": {
    "client_id": "r-5c20e9b4",
    "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
    "mentions": []
  }
}
EOF

import requests

url = "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies"

payload = { "reply": {
        "client_id": "r-5c20e9b4",
        "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
        "mentions": []
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    reply: {
      client_id: 'r-5c20e9b4',
      body: JSON.stringify('Agreed. Let\'s drop the font size a step below 768px rather than rewording it.'),
      mentions: []
    }
  })
};

fetch('https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'reply' => [
        'client_id' => 'r-5c20e9b4',
        'body' => 'Agreed. Let\'s drop the font size a step below 768px rather than rewording it.',
        'mentions' => [
                
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies"

	payload := strings.NewReader("{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "preview_comment": {
    "id": 31877,
    "run_id": null,
    "lock_version": 3,
    "client_id": "c-3f9a2e71",
    "n": 4,
    "body": "The hero headline wraps onto three lines on mobile. Can we tighten it so it fits on two?",
    "status": "open",
    "status_at_ms": 1789398131000,
    "page_url": "/",
    "author_name": "Michael Scott",
    "created_at_ms": 1789398131000,
    "theme_changed_at": null,
    "template_id": 902114,
    "section": {
      "id": "hero-banner-1",
      "type": "hero-banner"
    },
    "block": null,
    "target": {
      "tag": "h1",
      "selector": "section[data-section-id=\"hero-banner-1\"] h1.hero__title",
      "text": "Limitless Paper in a Paperless World",
      "html": "<h1 class=\"hero__title\">Limitless Paper in a Paperless World</h1>"
    },
    "pin": {
      "x": 48.2,
      "y": 22.7,
      "ox": 0.41,
      "oy": 0.63
    },
    "mentions": [
      {
        "id": "52018",
        "name": "Pam Beesly"
      }
    ],
    "mentioned_project": null,
    "proof_baseline": null,
    "work_item": null,
    "board_position": null,
    "board_position_at_ms": null,
    "assignee": null,
    "assigner": null,
    "assigned_at_ms": null,
    "priority": null,
    "priority_at_ms": null,
    "replies": [
      {
        "client_id": "r-5c20e9b4",
        "run_id": null,
        "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
        "author_name": "Pam Beesly",
        "posted_by": null,
        "created_at_ms": 1789398277000,
        "mentions": [],
        "shot": null,
        "proof": null
      }
    ]
  },
  "status": 201,
  "meta": {
    "request_uuid": "7c1e9a52-4b3d-4f0e-9d2a-81f6c3b5e240",
    "timestamp": "2026-09-14T15:04:37Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

Authorizations

Authorization

string

header

required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Path Parameters

theme_id

integer

required

Id of the theme the comment belongs to.

client_id

string

required

Client-generated id of the comment being replied to.

Body

application/json

object

required

Show child attributes

Response

The comment, with the reply appended.

A single comment, wrapped in the standard response envelope.

preview_comment

object

required

A comment pinned to an element on a theme's preview.

Show child attributes

status

integer

required

HTTP status, repeated in the body.

meta

object

required

Envelope metadata returned on every preview-comment response.

Show child attributes

Reply to a preview comment

curl --request POST \
  --url https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data @- <<EOF
{
  "reply": {
    "client_id": "r-5c20e9b4",
    "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
    "mentions": []
  }
}
EOF

import requests

url = "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies"

payload = { "reply": {
        "client_id": "r-5c20e9b4",
        "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
        "mentions": []
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    reply: {
      client_id: 'r-5c20e9b4',
      body: JSON.stringify('Agreed. Let\'s drop the font size a step below 768px rather than rewording it.'),
      mentions: []
    }
  })
};

fetch('https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'reply' => [
        'client_id' => 'r-5c20e9b4',
        'body' => 'Agreed. Let\'s drop the font size a step below 768px rather than rewording it.',
        'mentions' => [
                
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies"

	payload := strings.NewReader("{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.fluid.app/api/v202604/themes/{theme_id}/preview_comments/{client_id}/replies")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"reply\": {\n    \"client_id\": \"r-5c20e9b4\",\n    \"body\": \"Agreed. Let's drop the font size a step below 768px rather than rewording it.\",\n    \"mentions\": []\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "preview_comment": {
    "id": 31877,
    "run_id": null,
    "lock_version": 3,
    "client_id": "c-3f9a2e71",
    "n": 4,
    "body": "The hero headline wraps onto three lines on mobile. Can we tighten it so it fits on two?",
    "status": "open",
    "status_at_ms": 1789398131000,
    "page_url": "/",
    "author_name": "Michael Scott",
    "created_at_ms": 1789398131000,
    "theme_changed_at": null,
    "template_id": 902114,
    "section": {
      "id": "hero-banner-1",
      "type": "hero-banner"
    },
    "block": null,
    "target": {
      "tag": "h1",
      "selector": "section[data-section-id=\"hero-banner-1\"] h1.hero__title",
      "text": "Limitless Paper in a Paperless World",
      "html": "<h1 class=\"hero__title\">Limitless Paper in a Paperless World</h1>"
    },
    "pin": {
      "x": 48.2,
      "y": 22.7,
      "ox": 0.41,
      "oy": 0.63
    },
    "mentions": [
      {
        "id": "52018",
        "name": "Pam Beesly"
      }
    ],
    "mentioned_project": null,
    "proof_baseline": null,
    "work_item": null,
    "board_position": null,
    "board_position_at_ms": null,
    "assignee": null,
    "assigner": null,
    "assigned_at_ms": null,
    "priority": null,
    "priority_at_ms": null,
    "replies": [
      {
        "client_id": "r-5c20e9b4",
        "run_id": null,
        "body": "Agreed. Let's drop the font size a step below 768px rather than rewording it.",
        "author_name": "Pam Beesly",
        "posted_by": null,
        "created_at_ms": 1789398277000,
        "mentions": [],
        "shot": null,
        "proof": null
      }
    ]
  },
  "status": 201,
  "meta": {
    "request_uuid": "7c1e9a52-4b3d-4f0e-9d2a-81f6c3b5e240",
    "timestamp": "2026-09-14T15:04:37Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "error": {
    "message": "<string>",
    "details": {}
  },
  "status": 123,
  "meta": {
    "request_uuid": "<string>",
    "timestamp": "2023-11-07T05:31:56Z"
  }
}

Overview

Storefront

Commerce

Checkout

Member API

Member Sites APIs

Messaging

Cowork

People

Payments

DAM

Website

Portal

Mobile app

Content and tools

Analytics

Sales channels

Settings

FairShare SDK

Droplets

Developers

Unsorted endpoints

Portal & Widgets

Reply to a preview comment

Authorizations

Path Parameters

Body

Response