Card actions
A card combines text with up to three buttons. These examples build two cards with the same approval and rejection actions; the second adds a Details button.
Slackblocks preserves the order supplied to actions in the serialized payload.
Slack controls the visual arrangement, so array order is not a positioning API:
| Card | Visual arrangement |
|---|---|
| Two buttons | Reject and Approve form a group on the right, with Reject first. |
| Three buttons | Reject sits at the far left; Details and Approve form a group on the right. |
Primary buttons appear furthest right. Adding the third button moves the danger button across the card. This card-specific rule does not change an ordinary Actions block.
The official card reference contains this clarification, first observed on 6 November 2026. The two- and three-button arrangements were also verified in the Slack stress workspace on 7 November 2026, including all six input orders for one primary, one danger, and one default button. This is a documentation clarification, with no new field or caller migration.
Output
Local preview of the selected language’s tested example. Slack client appearance may differ; controls here do not send requests.
Two buttons
Review release-42.
Three buttons
Review release-42.
Serialized output
{
"channel": "C1",
"mrkdwn": true,
"blocks": [
{
"type": "card",
"block_id": "card_two",
"title": {
"type": "mrkdwn",
"text": "Two buttons"
},
"body": {
"type": "mrkdwn",
"text": "Review release-42."
},
"actions": [
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Approve"
},
"action_id": "approve",
"style": "primary",
"value": "release-42"
},
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Reject"
},
"action_id": "reject",
"style": "danger",
"value": "release-42"
}
]
},
{
"type": "card",
"block_id": "card_three",
"title": {
"type": "mrkdwn",
"text": "Three buttons"
},
"body": {
"type": "mrkdwn",
"text": "Review release-42."
},
"actions": [
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Approve"
},
"action_id": "approve",
"style": "primary",
"value": "release-42"
},
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Reject"
},
"action_id": "reject",
"style": "danger",
"value": "release-42"
},
{
"type": "button",
"text": {
"type": "plain_text",
"text": "Details"
},
"action_id": "details",
"value": "release-42"
}
]
}
],
"text": "Card actions"
}
Build the cards
The code deliberately supplies Approve before Reject. Expand Serialized output above to compare that array with the preview's visual arrangement. Each button retains its action ID and request value. Your application still needs to handle and acknowledge interactions; constructing these messages does not send them.
from slackblocks import Button, CardBlock, Message
approve = Button("Approve", action_id="approve", value="release-42", style="primary")
reject = Button("Reject", action_id="reject", value="release-42", style="danger")
details = Button("Details", action_id="details", value="release-42")
message = Message(channel="C1", text="Card actions", blocks=[
CardBlock(title="Two buttons", body="Review release-42.",
actions=[approve, reject], block_id="card_two"),
CardBlock(title="Three buttons", body="Review release-42.",
actions=[approve, reject, details], block_id="card_three"),
])
print(message.json())
import * as S from "@nicklambourne/slackblocks";
const approve = S.Button().text("Approve").actionId("approve").value("release-42").style("primary");
const reject = S.Button().text("Reject").actionId("reject").value("release-42").style("danger");
const details = S.Button().text("Details").actionId("details").value("release-42");
const message = S.Message().channel("C1").text("Card actions").blocks(
S.CardBlock().title("Two buttons").body("Review release-42.")
.actions(approve, reject).blockId("card_two"),
S.CardBlock().title("Three buttons").body("Review release-42.")
.actions(approve, reject, details).blockId("card_three"),
).build();
console.log(JSON.stringify(message));
package main
import (
"encoding/json"
"os"
s "github.com/nicklambourne/slackblocks/go/v3"
)
func main() {
approve := s.NewButton().Text("Approve").ActionID("approve").Value("release-42").Style("primary")
reject := s.NewButton().Text("Reject").ActionID("reject").Value("release-42").Style("danger")
details := s.NewButton().Text("Details").ActionID("details").Value("release-42")
message, err := s.NewMessage().Channel("C1").Text("Card actions").Blocks(
s.NewCardBlock().Title("Two buttons").Body("Review release-42.").
Actions(approve, reject).BlockID("card_two"),
s.NewCardBlock().Title("Three buttons").Body("Review release-42.").
Actions(approve, reject, details).BlockID("card_three"),
).Build()
if err != nil { panic(err) }
if err := json.NewEncoder(os.Stdout).Encode(message); err != nil { panic(err) }
}
import io.github.nicklambourne.slackblocks.block.CardBlock;
import io.github.nicklambourne.slackblocks.element.ButtonElement;
import io.github.nicklambourne.slackblocks.element.ButtonStyle;
import io.github.nicklambourne.slackblocks.payload.MessagePayload;
public final class Recipe {
public static void main(String[] args) {
var approve = ButtonElement.builder().text("Approve").actionId("approve")
.value("release-42").style(ButtonStyle.PRIMARY).build();
var reject = ButtonElement.builder().text("Reject").actionId("reject")
.value("release-42").style(ButtonStyle.DANGER).build();
var details = ButtonElement.builder().text("Details").actionId("details").value("release-42").build();
var message = MessagePayload.builder().channel("C1").text("Card actions").blocks(
CardBlock.builder().title("Two buttons").body("Review release-42.")
.actions(approve, reject).blockId("card_two").build(),
CardBlock.builder().title("Three buttons").body("Review release-42.")
.actions(approve, reject, details).blockId("card_three").build()
).build();
System.out.println(message.toJson());
}
}
using System;
using Slackblocks;
using Slackblocks.Blocks;
using Slackblocks.Elements;
using Slackblocks.Payloads;
var approve = new ButtonElement("Approve", actionId: "approve", value: "release-42", style: ButtonStyle.Primary);
var reject = new ButtonElement("Reject", actionId: "reject", value: "release-42", style: ButtonStyle.Danger);
var details = new ButtonElement("Details", actionId: "details", value: "release-42");
var message = new MessagePayload("C1", text: "Card actions", blocks: [
new CardBlock(title: "Two buttons", body: "Review release-42.",
actions: [approve, reject], blockId: "card_two"),
new CardBlock(title: "Three buttons", body: "Review release-42.",
actions: [approve, reject, details], blockId: "card_three"),
]);
Console.WriteLine(message.ToJson());
require "slackblocks"
include Slackblocks
approve = ButtonElement.new(text: "Approve", action_id: "approve", value: "release-42", style: ButtonStyle::PRIMARY)
reject = ButtonElement.new(text: "Reject", action_id: "reject", value: "release-42", style: ButtonStyle::DANGER)
details = ButtonElement.new(text: "Details", action_id: "details", value: "release-42")
message = MessagePayload.new(channel: "C1", text: "Card actions", blocks: [
CardBlock.new(title: "Two buttons", body: "Review release-42.",
actions: [approve, reject], block_id: "card_two"),
CardBlock.new(title: "Three buttons", body: "Review release-42.",
actions: [approve, reject, details], block_id: "card_three")
])
puts message.to_json
use slackblocks::*;
fn main() -> Result<(), Box<dyn std::error::Error>> {
let approve = ButtonElement::builder().text("Approve").action_id("approve")
.value("release-42").style(ButtonStyle::Primary).build()?;
let reject = ButtonElement::builder().text("Reject").action_id("reject")
.value("release-42").style(ButtonStyle::Danger).build()?;
let details = ButtonElement::builder().text("Details").action_id("details")
.value("release-42").build()?;
let two = CardBlock::builder().title("Two buttons").body("Review release-42.")
.action(approve.clone()).action(reject.clone()).block_id("card_two").build()?;
let three = CardBlock::builder().title("Three buttons").body("Review release-42.")
.action(approve).action(reject).action(details).block_id("card_three").build()?;
let message = MessagePayload::builder("C1").text("Card actions").block(two).block(three).build()?;
println!("{}", serde_json::to_string(&message)?);
Ok(())
}
<?php
declare(strict_types=1);
require 'vendor/autoload.php';
use Slackblocks as S;
$approve = new S\ButtonElement(text: 'Approve', actionId: 'approve', value: 'release-42', style: S\ButtonStyle::Primary);
$reject = new S\ButtonElement(text: 'Reject', actionId: 'reject', value: 'release-42', style: S\ButtonStyle::Danger);
$details = new S\ButtonElement(text: 'Details', actionId: 'details', value: 'release-42');
$message = new S\MessagePayload(channel: 'C1', text: 'Card actions', blocks: [
new S\CardBlock(title: 'Two buttons', body: 'Review release-42.',
actions: [$approve, $reject], blockId: 'card_two'),
new S\CardBlock(title: 'Three buttons', body: 'Review release-42.',
actions: [$approve, $reject, $details], blockId: 'card_three'),
]);
echo $message->toJson();
alias Slackblocks.{Message, Blocks.Card, Elements.Button}
approve = Button.new!(text: "Approve", action_id: "approve", value: "release-42", style: :primary)
reject = Button.new!(text: "Reject", action_id: "reject", value: "release-42", style: :danger)
details = Button.new!(text: "Details", action_id: "details", value: "release-42")
Message.new!(channel: "C1", text: "Card actions", blocks: [
Card.new!(title: "Two buttons", body: "Review release-42.",
actions: [approve, reject], block_id: "card_two"),
Card.new!(title: "Three buttons", body: "Review release-42.",
actions: [approve, reject, details], block_id: "card_three")
]) |> Slackblocks.to_map!()
{-# LANGUAGE OverloadedStrings #-}
import Data.Aeson (encode)
import Slackblocks
example = do
yes <- buildPlainText (plainText "Approve")
no <- buildPlainText (plainText "Reject")
more <- buildPlainText (plainText "Details")
approve <- buildButtonElement ((buttonElement yes) {buttonElementActionId = Just "approve", buttonElementValue = Just "release-42", buttonElementStyle = Just ButtonStylePrimary})
reject <- buildButtonElement ((buttonElement no) {buttonElementActionId = Just "reject", buttonElementValue = Just "release-42", buttonElementStyle = Just ButtonStyleDanger})
details <- buildButtonElement ((buttonElement more) {buttonElementActionId = Just "details", buttonElementValue = Just "release-42"})
twoTitle <- buildMarkdownText (markdownText "Two buttons")
threeTitle <- buildMarkdownText (markdownText "Three buttons")
body <- buildMarkdownText (markdownText "Review release-42.")
two <- buildCardBlock (cardBlock {cardBlockTitle = Just (markdownTextAsText twoTitle), cardBlockBody = Just (markdownTextAsText body), cardBlockActions = Just [approve, reject], cardBlockBlockId = Just "card_two"})
three <- buildCardBlock (cardBlock {cardBlockTitle = Just (markdownTextAsText threeTitle), cardBlockBody = Just (markdownTextAsText body), cardBlockActions = Just [approve, reject, details], cardBlockBlockId = Just "card_three"})
buildMessagePayload ((messagePayload "C1") {messagePayloadText = Just "Card actions", messagePayloadBlocks = Just [cardBlockAsBlock two, cardBlockAsBlock three]})