feat(methods): add chat.postMessage example

.github/workflows/test.yml

@@ -16,6 +16,7 @@ jobs:
           - "ai/slackbot-mcp-client/rich-responses/mcp-apps"
           - "ai/slackbot-mcp-client/slack-identity"
           - "block-kit"
+          - "methods"
     steps:
       - name: Checkout code
         uses: actions/checkout@v7

README.md

@@ -6,3 +6,4 @@ This collections of examples highlights features of a Slack app in the language
 
 - **[AI in Slack](./ai)**: Agent experiences and MCP features in an interactive conversation interface.
 - **[Block Kit](./block-kit)**: The framework of visual components arranged to create app layouts.
+- **[Methods](./methods)**: Individual Slack Web API method calls with the `slack_sdk` `WebClient`.

methods/.gitignore

@@ -0,0 +1,5 @@
+__pycache__
+.mypy_cache
+.pytest_cache
+.ruff_cache
+.venv

methods/README.md

@@ -0,0 +1,20 @@
+# Methods
+
+Individual Slack Web API method calls with the `slack_sdk` `WebClient`.
+
+Read the [docs](https://docs.slack.dev/reference/methods) to explore every method, or explore implementations of specific families.
+
+## What's on display
+
+### chat
+
+- **[chat.postMessage](https://docs.slack.dev/reference/methods/chat.postmessage)**: Sends a message to a channel. [Implementation](./src/chat/chat_post_message.py).
+
+## Running an example
+
+Each family ships a [`manifest.json`](./src/chat/manifest.json) requesting only the scopes it needs (`chat` → `chat:write`). Create an app from it, then set a bot token and run an example module directly:
+
+```sh
+export SLACK_TOKEN="xoxb-your-token"
+python -m src.chat.chat_post_message
+```

methods/requirements.txt

@@ -0,0 +1,4 @@
+mypy==2.3.0
+pytest==9.1.1
+ruff==0.15.21
+slack_sdk==3.43.0

methods/src/chat/chat_post_message.py

@@ -0,0 +1,27 @@
+import os
+
+from slack_sdk import WebClient
+from slack_sdk.web import SlackResponse
+
+
+def example01(client: WebClient) -> SlackResponse:
+    """
+    Sends a message to a channel.
+    https://docs.slack.dev/reference/methods/chat.postmessage
+    """
+    # Call the chat.postMessage method using the WebClient
+    response = client.chat_postMessage(
+        channel="C123ABC456",
+        text="Here's a message for you",
+    )
+    return response
+
+
+if __name__ == "__main__":
+    # Read a token from the environment variables
+    token = os.environ.get("SLACK_TOKEN")
+
+    # Initialize a WebClient with the given token
+    client = WebClient(token=token)
+
+    print(example01(client))

methods/src/chat/manifest.json

@@ -0,0 +1,22 @@
+{
+  "display_information": {
+    "name": "Slack API Methods",
+    "description": "Example implementations to call \"chat\" methods"
+  },
+  "features": {
+    "bot_user": {
+      "display_name": "Slack API Methods",
+      "always_online": true
+    }
+  },
+  "oauth_config": {
+    "scopes": {
+      "bot": ["chat:write"]
+    }
+  },
+  "settings": {
+    "org_deploy_enabled": true,
+    "socket_mode_enabled": false,
+    "token_rotation_enabled": false
+  }
+}

methods/tests/chat/test_chat_post_message.py

@@ -0,0 +1,43 @@
+import json
+import threading
+from http.server import BaseHTTPRequestHandler, HTTPServer
+
+from slack_sdk import WebClient
+
+from src.chat import chat_post_message
+
+
+class _CapturingHandler(BaseHTTPRequestHandler):
+    captured: dict = {}
+
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length", 0))
+        _CapturingHandler.captured = {
+            "path": self.path,
+            "body": self.rfile.read(length).decode(),
+        }
+        self.send_response(200)
+        self.send_header("Content-Type", "application/json")
+        self.end_headers()
+        self.wfile.write(b'{"ok": true}')
+
+    def log_message(self, *args):
+        pass
+
+
+def test_example01():
+    server = HTTPServer(("127.0.0.1", 0), _CapturingHandler)
+    port = server.server_address[1]
+    threading.Thread(target=server.handle_request, daemon=True).start()
+
+    client = WebClient(token="xoxb-test", base_url=f"http://127.0.0.1:{port}/api/")
+    response = chat_post_message.example01(client)
+
+    assert response["ok"] is True
+
+    captured = _CapturingHandler.captured
+    assert captured["path"] == "/api/chat.postMessage"
+    assert json.loads(captured["body"]) == {
+        "channel": "C123ABC456",
+        "text": "Here's a message for you",
+    }