From 792b7b1b0553bea7f4b56df3673b26bf53a5c26a Mon Sep 17 00:00:00 2001
From: jorrick <jorrick.sleijster@adyen.com>
Date: Thu, 25 Sep 2025 15:27:09 +0200
Subject: [PATCH 1/2] =?UTF-8?q?=E2=9C=A8=20Add=20function=20to=20show=20me?=
 =?UTF-8?q?ssage=20in=20slacks=20Block=20kit=20builder?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 blockkit/core.py   | 8 ++++++++
 docs/quickstart.md | 5 +++++
 2 files changed, 13 insertions(+)

diff --git a/blockkit/core.py b/blockkit/core.py
index 99b2dda..75ab7e3 100644
--- a/blockkit/core.py
+++ b/blockkit/core.py
@@ -4,6 +4,7 @@
 from abc import ABC, abstractmethod
 from datetime import date, datetime, time
 from typing import Any, Final, Literal, Self, TypeAlias, get_args
+from urllib import parse
 from zoneinfo import ZoneInfo
 
 from blockkit.utils import is_md
@@ -3135,6 +3136,13 @@ def thread_ts(self, thread_ts: str | int | float | None) -> Self:
     def mrkdwn(self, mrkdwn: bool | None = True) -> Self:
         return self._add_field("mrkdwn", mrkdwn, validators=[Typed(bool)])
 
+    def get_block_kit_explorer_url(self) -> str:
+        """This function returns a link visualising what the message would look like in Slack."""
+        compact_json = json.dumps(self.build(), separators=(",", ":"))
+        encoded_json = parse.quote(compact_json)
+        base_url = "https://app.slack.com/block-kit-builder#"
+        return base_url + encoded_json
+
 
 ModalBlock: TypeAlias = (
     Actions | Context | Divider | Header | Image | Input | RichText | Section | Video
diff --git a/docs/quickstart.md b/docs/quickstart.md
index 90db5d1..0f9e95e 100644
--- a/docs/quickstart.md
+++ b/docs/quickstart.md
@@ -28,6 +28,11 @@ message = (
 
 That's it. Real Slack BlockKit JSON. Ready to send.
 
+Wondering what it looks like now in Slack? You can check your exact message in the Slack block kit builder before sending it;
+```python
+message.get_block_kit_explorer_url()
+```
+
 ## Send it
 
 ```python

From b5b4348afc1fcec5236d69d754ddb2b4c66202c0 Mon Sep 17 00:00:00 2001
From: Dima <imryche13@gmail.com>
Date: Sat, 27 Sep 2025 18:59:43 +0200
Subject: [PATCH 2/2] let's have `builder_url()` for all surfaces

---
 blockkit/core.py   | 45 +++++++++++++++++++++++++++++++++++----------
 tests/test_core.py |  1 +
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/blockkit/core.py b/blockkit/core.py
index 75ab7e3..09d98f5 100644
--- a/blockkit/core.py
+++ b/blockkit/core.py
@@ -732,6 +732,28 @@ def external_id(self, external_id: str | None) -> Self:
         )
 
 
+class BuilderUrlMixin:
+    def builder_url(self) -> str:
+        """
+        Returns a URL to preview this message in Slack's Block Kit Builder.
+        """
+
+        surface = self.build()
+        filter_fields = {
+            Message: ("blocks",),
+            Modal: ("type", "title", "submit", "close", "blocks"),
+            Home: ("type", "blocks"),
+        }.get(type(self), None)
+
+        if filter_fields:
+            surface = {k: v for k, v in surface.items() if k in filter_fields}
+
+        encoded_json = parse.quote(
+            json.dumps(surface, ensure_ascii=False, separators=(",", ":")), safe=""
+        )
+        return f"https://app.slack.com/block-kit-builder#{encoded_json}"
+
+
 """
 Composition objects
 """
@@ -3093,7 +3115,7 @@ def author_name(self, author_name: str | None) -> Self:
 )
 
 
-class Message(Component):
+class Message(Component, BuilderUrlMixin):
     """
     Message surface
 
@@ -3136,13 +3158,6 @@ def thread_ts(self, thread_ts: str | int | float | None) -> Self:
     def mrkdwn(self, mrkdwn: bool | None = True) -> Self:
         return self._add_field("mrkdwn", mrkdwn, validators=[Typed(bool)])
 
-    def get_block_kit_explorer_url(self) -> str:
-        """This function returns a link visualising what the message would look like in Slack."""
-        compact_json = json.dumps(self.build(), separators=(",", ":"))
-        encoded_json = parse.quote(compact_json)
-        base_url = "https://app.slack.com/block-kit-builder#"
-        return base_url + encoded_json
-
 
 ModalBlock: TypeAlias = (
     Actions | Context | Divider | Header | Image | Input | RichText | Section | Video
@@ -3150,7 +3165,12 @@ def get_block_kit_explorer_url(self) -> str:
 
 
 class Modal(
-    Component, BlocksMixin, PrivateMetadataMixin, CallbackIdMixin, ExternalIdMixin
+    Component,
+    BlocksMixin,
+    PrivateMetadataMixin,
+    CallbackIdMixin,
+    ExternalIdMixin,
+    BuilderUrlMixin,
 ):
     """
     Modal surface
@@ -3228,7 +3248,12 @@ def submit_disabled(self, submit_disabled: bool | None = True) -> Self:
 
 
 class Home(
-    Component, BlocksMixin, PrivateMetadataMixin, CallbackIdMixin, ExternalIdMixin
+    Component,
+    BlocksMixin,
+    PrivateMetadataMixin,
+    CallbackIdMixin,
+    ExternalIdMixin,
+    BuilderUrlMixin,
 ):
     """
     App Home surface
diff --git a/tests/test_core.py b/tests/test_core.py
index 6277bb1..00bbe95 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -3544,3 +3544,4 @@ def test_builds(self):
             .external_id("alice_intro")
             .build()
         )
+        assert got == want