feat: add message editing support

- Add matrix-edit.py to modify existing messages
- Uses m.replace relation type per Matrix spec
- Supports markdown formatting in edits
- Bump version to 1.5.0

Author: Netresearch

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "matrix-communication",
-  "version": "1.4.2",
+  "version": "1.5.0",
   "description": "Agentic Skill for Matrix chat communication. Send messages to Matrix rooms on behalf of users via access token authentication. Works with any Matrix homeserver.",
   "author": {
     "name": "Netresearch DTT GmbH",

README.md

@@ -19,6 +19,8 @@ This skill enables AI coding agents to send messages to Matrix chat rooms on beh
 - **Emotes** - `/me` style action messages (`--emote`)
 - **Thread replies** - Keep discussions organized (`--thread`)
 - **Reactions** - Add emoji reactions to messages (✅ 👍 🚀)
+- **Edit messages** - Modify sent messages
+- **Redact messages** - Delete messages from rooms
 - **Visual effects** - Confetti 🎉, fireworks 🎆, snowfall ❄️ (Element clients)
 - **List rooms** to find the right destination
 - **Read messages** - both unencrypted and E2EE decryption
@@ -155,6 +157,7 @@ matrix-skill/
 │   ├── matrix-rooms.py          # List joined rooms
 │   ├── matrix-resolve.py        # Resolve room aliases
 │   ├── matrix-react.py          # React to messages
+│   ├── matrix-edit.py           # Edit existing messages
 │   ├── matrix-redact.py         # Delete/redact messages
 │   ├── matrix-e2ee-setup.py     # E2EE device setup
 │   └── matrix-e2ee-verify.py    # Device verification

scripts/matrix-edit.py

@@ -0,0 +1,281 @@
+#!/usr/bin/env python3
+"""Edit an existing message in a Matrix room.
+
+Usage:
+    matrix-edit.py ROOM EVENT_ID NEW_MESSAGE
+    matrix-edit.py --help
+
+Arguments:
+    ROOM        Room alias (#room:server) or room ID (!id:server)
+    EVENT_ID    Event ID of the message to edit ($xxx:server)
+    NEW_MESSAGE The new message content (replaces original)
+
+Options:
+    --json      Output as JSON
+    --quiet     Minimal output
+    --debug     Show debug information
+    --help      Show this help
+"""
+
+import json
+import re
+import sys
+import time
+import urllib.request
+import urllib.error
+import urllib.parse
+from pathlib import Path
+
+
+def load_config() -> dict:
+    """Load Matrix config from ~/.config/matrix/config.json"""
+    config_path = Path.home() / ".config" / "matrix" / "config.json"
+    if not config_path.exists():
+        print(f"Error: Config file not found: {config_path}", file=sys.stderr)
+        sys.exit(1)
+
+    with open(config_path) as f:
+        config = json.load(f)
+
+    # Add bot_prefix handling
+    return config
+
+
+def matrix_request(config: dict, method: str, endpoint: str, data: dict = None) -> dict:
+    """Make a Matrix API request."""
+    url = f"{config['homeserver']}/_matrix/client/v3{endpoint}"
+    headers = {
+        "Authorization": f"Bearer {config['access_token']}",
+        "Content-Type": "application/json"
+    }
+
+    body = json.dumps(data).encode() if data else None
+    req = urllib.request.Request(url, data=body, headers=headers, method=method)
+
+    try:
+        with urllib.request.urlopen(req) as response:
+            return json.loads(response.read().decode())
+    except urllib.error.HTTPError as e:
+        error_body = e.read().decode()
+        try:
+            error_json = json.loads(error_body)
+            return {"error": error_json.get("error", error_body), "errcode": error_json.get("errcode")}
+        except:
+            return {"error": error_body, "errcode": str(e.code)}
+
+
+def resolve_room_alias(config: dict, alias: str) -> str:
+    """Resolve a room alias to room ID."""
+    encoded_alias = urllib.parse.quote(alias, safe='')
+    result = matrix_request(config, "GET", f"/directory/room/{encoded_alias}")
+    if "room_id" in result:
+        return result["room_id"]
+    raise ValueError(f"Could not resolve room alias: {result.get('error', 'Unknown error')}")
+
+
+def shorten_service_urls(text: str) -> str:
+    """Convert service URLs to shorter linked text."""
+    text = re.sub(
+        r'https?://[^/]+/browse/([A-Z][A-Z0-9]+-\d+)',
+        r'[\1](https://\g<0>)',
+        text
+    )
+    text = re.sub(r'\(https://https?://', r'(https://', text)
+    text = re.sub(
+        r'https?://github\.com/([^/]+)/([^/]+)/(issues|pull)/(\d+)',
+        r'[\1/\2#\4](\g<0>)',
+        text
+    )
+    text = re.sub(
+        r'https?://github\.com/([^/]+)/([^/]+)/commit/([a-f0-9]{7,40})',
+        r'[\1/\2@\3](\g<0>)',
+        text
+    )
+    text = re.sub(
+        r'https?://[^/]+/([^/]+/[^/]+)/-/(issues|merge_requests)/(\d+)',
+        r'[\1#\3](\g<0>)',
+        text
+    )
+    return text
+
+
+def markdown_to_html(text: str) -> str:
+    """Convert markdown to Matrix HTML."""
+    html = shorten_service_urls(text)
+
+    code_blocks = []
+    def save_code_block(match):
+        lang = match.group(1) or ''
+        code = match.group(2)
+        idx = len(code_blocks)
+        if lang:
+            code_blocks.append(f'<pre><code class="language-{lang}">{code}</code></pre>')
+        else:
+            code_blocks.append(f'<pre><code>{code}</code></pre>')
+        return f'{{{{CODEBLOCK_{idx}}}}}'
+
+    html = re.sub(r'```(\w*)\n(.*?)```', save_code_block, html, flags=re.DOTALL)
+    html = re.sub(r'\|\|(.+?)\|\|', r'<span data-mx-spoiler>\1</span>', html)
+    html = re.sub(r'\[([^\]]+)\]\(([^)]+)\)', r'<a href="\2">\1</a>', html)
+    html = re.sub(
+        r'(?<!["\'/])(@[a-zA-Z0-9._=-]+:[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})',
+        r'<a href="https://matrix.to/#/\1">\1</a>',
+        html
+    )
+    html = re.sub(
+        r'(?<!["\'/])(#[a-zA-Z0-9._=-]+:[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})',
+        r'<a href="https://matrix.to/#/\1">\1</a>',
+        html
+    )
+    html = re.sub(r'~~(.+?)~~', r'<del>\1</del>', html)
+    html = re.sub(r'\*\*(.+?)\*\*', r'<strong>\1</strong>', html)
+    html = re.sub(r'\*(.+?)\*', r'<em>\1</em>', html)
+    html = re.sub(r'`(.+?)`', r'<code>\1</code>', html)
+    html = re.sub(r'\n{2,}', '\n', html)
+
+    lines = html.split('\n')
+    in_list = False
+    in_quote = False
+    result = []
+
+    for line in lines:
+        stripped = line.strip()
+        if stripped.startswith('> '):
+            if not in_quote:
+                if in_list:
+                    result.append('</ul>')
+                    in_list = False
+                result.append('<blockquote>')
+                in_quote = True
+            result.append(stripped[2:])
+        elif stripped.startswith('- '):
+            if in_quote:
+                result.append('</blockquote>')
+                in_quote = False
+            if not in_list:
+                result.append('<ul>')
+                in_list = True
+            result.append(f'<li>{stripped[2:]}</li>')
+        elif stripped == '':
+            if in_quote:
+                result.append('</blockquote>')
+                in_quote = False
+            continue
+        else:
+            if in_quote:
+                result.append('</blockquote>')
+                in_quote = False
+            if in_list:
+                result.append('</ul>')
+                in_list = False
+            result.append(line)
+
+    if in_quote:
+        result.append('</blockquote>')
+    if in_list:
+        result.append('</ul>')
+
+    html = '{{BR}}'.join(result)
+    html = re.sub(r'\{\{BR\}\}(?=<ul>|<li>|</ul>|</li>|<blockquote>|</blockquote>|<pre>)', '', html)
+    html = re.sub(r'(</ul>|</li>|</blockquote>|</pre>)\{\{BR\}\}', r'\1', html)
+    html = re.sub(r'(<blockquote>)\{\{BR\}\}', r'\1', html)
+    html = html.replace('{{BR}}', '<br>')
+
+    for idx, block in enumerate(code_blocks):
+        html = html.replace(f'{{{{CODEBLOCK_{idx}}}}}', block)
+
+    return html
+
+
+def clean_message(message: str) -> str:
+    """Clean message from bash escaping artifacts."""
+    return message.replace('\\!', '!')
+
+
+def edit_message(config: dict, room_id: str, event_id: str, new_message: str) -> dict:
+    """Edit an existing message in a Matrix room."""
+    txn_id = str(int(time.time() * 1000))
+
+    # Build the replacement content
+    content = {
+        "msgtype": "m.text",
+        "body": f"* {new_message}",  # Prefix with * for fallback
+        "m.new_content": {
+            "msgtype": "m.text",
+            "body": new_message,
+        },
+        "m.relates_to": {
+            "rel_type": "m.replace",
+            "event_id": event_id,
+        }
+    }
+
+    # Add HTML formatting
+    html = markdown_to_html(new_message)
+    if html != new_message:
+        content["format"] = "org.matrix.custom.html"
+        content["formatted_body"] = f"* {html}"
+        content["m.new_content"]["format"] = "org.matrix.custom.html"
+        content["m.new_content"]["formatted_body"] = html
+
+    return matrix_request(
+        config,
+        "PUT",
+        f"/rooms/{urllib.parse.quote(room_id, safe='')}/send/m.room.message/{txn_id}",
+        content
+    )
+
+
+def main():
+    import argparse
+
+    parser = argparse.ArgumentParser(description="Edit a message in a Matrix room")
+    parser.add_argument("room", help="Room alias (#room:server) or room ID (!id:server)")
+    parser.add_argument("event_id", help="Event ID of the message to edit")
+    parser.add_argument("message", help="New message content")
+    parser.add_argument("--json", action="store_true", help="Output as JSON")
+    parser.add_argument("--quiet", "-q", action="store_true", help="Minimal output")
+    parser.add_argument("--debug", action="store_true", help="Show debug info")
+
+    args = parser.parse_args()
+
+    config = load_config()
+
+    # Clean message
+    message = clean_message(args.message)
+
+    # Resolve room alias if needed
+    room_id = args.room
+    if args.room.startswith("#"):
+        try:
+            room_id = resolve_room_alias(config, args.room)
+            if args.debug:
+                print(f"Resolved {args.room} -> {room_id}", file=sys.stderr)
+        except ValueError as e:
+            if args.json:
+                print(json.dumps({"error": str(e)}))
+            else:
+                print(f"Error: {e}", file=sys.stderr)
+            sys.exit(1)
+
+    # Edit message
+    result = edit_message(config, room_id, args.event_id, message)
+
+    if "error" in result:
+        if args.json:
+            print(json.dumps(result))
+        else:
+            print(f"Error: {result['error']}", file=sys.stderr)
+        sys.exit(1)
+
+    if args.json:
+        print(json.dumps(result))
+    elif args.quiet:
+        print(result.get("event_id", ""))
+    else:
+        print(f"Message edited in {args.room}")
+        print(f"Edit event ID: {result.get('event_id')}")
+
+
+if __name__ == "__main__":
+    main()

skills/matrix-communication/SKILL.md

@@ -51,6 +51,7 @@ All scripts are in the `scripts/` directory. Run with `uv run`.
 | `matrix-e2ee-setup.py` | One-time E2EE device setup |
 | `matrix-e2ee-verify.py` | Device verification (experimental) |
 | `matrix-react.py` | React to a message with emoji |
+| `matrix-edit.py` | Edit an existing message |
 | `matrix-redact.py` | Delete/redact a message |
 | `matrix-rooms.py` | List joined rooms |
 | `matrix-read.py` | Read recent messages (unencrypted only) |