YouTube Timestamp Generator & Auto-Poster#

Transforms a YouTube URL or a raw transcript string into SEO-optimized timestamps (chapters) powered by Gemini. Optionally appends the result directly to the description of a specific YouTube video or your latest upload via the YouTube Data API.

⚠️ Requirements Checklist#

Before using this skill, ensure you have:

• Python 3 installed
• Dependencies installed: pip install youtube-transcript-api google-generativeai google-auth-oauthlib google-api-python-client
• Gemini API Key available to pass as an argument
• credentials.json placed in scripts/ (only required for --post — download from Google Cloud Console as an OAuth 2.0 Desktop App client)

Features#

• 🕐 SEO Timestamps: Generates 0:00-based chapters with keyword-rich, scannable labels
• 🔗 Three Input Modes: Works from a YouTube URL, a raw transcript string, or auto-targets your latest video
• 🚀 Smart Auto-Poster: URL mode appends to that specific video; transcript and latest modes append to your latest upload
• 🛡️ Duplicate Prevention: The --latest mode checks for existing timestamps before attempting to generate new ones
• 🔑 Keyword Optimization: Natural integration of primary, secondary, and LSI keywords from the transcript
• 🧹 Clean Output: Returns only the final timestamps — no extra headings or commentary

Quick Start#

Mode 1 — YouTube URL#

Fetches the transcript from the video, generates SEO timestamps, and optionally appends them to the description of that specific video.

bash

# Generate only (view output)
python scripts/youtube_desc_generator.py --url "<youtube_url>" "<gemini_api_key>"

# Generate and post to that video
python scripts/youtube_desc_generator.py --url "<youtube_url>" "<gemini_api_key>" --post

Mode 2 — Raw Transcript Text#

Reads a raw transcript string, generates SEO timestamps, and optionally appends them to the description of your latest YouTube upload.

bash

# Generate only (view output)
python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "<gemini_api_key>"

# Generate and post to latest video
python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "<gemini_api_key>" --post

Mode 3 — Latest Video#

Automatically fetches your most recent video, checks if timestamps already exist (to prevent duplicates), downloads the transcript, generates SEO timestamps, and optionally appends them to the description.

bash

# Generate and post timestamps for your latest video (if they don't already exist)
python scripts/youtube_desc_generator.py --latest "<gemini_api_key>" --post

Examples:

bash

python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY"
python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY" --post
python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "$GEMINI_API_KEY" --post

Raw Transcript Text Format#

When using --transcript, the transcript must be a string with timestamps in MM:SS format, separated by newlines:

text

0:00 Welcome to this video about AI agents.
0:12 Today we're going to cover what an AI agent actually is.
1:00 Let me show you a live demo of an agent booking a flight.
...

Natural Language Command Mapping#

When the user speaks naturally, map their intent to the correct command using the table below. Always extract the YouTube URL or transcript text from their message and substitute it into the command.

What the user saysCommand to run"Create timestamps for my latest video"python scripts/youtube_desc_generator.py --latest "$GEMINI_API_KEY" --post"Generate timestamps for this video: https://youtu.be/abc123"python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY""Create SEO chapters from this YouTube link: https://youtu.be/abc123"python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY""Give me the timestamps for this video: https://youtu.be/abc123"python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY""Generate timestamps for this video and post it: https://youtu.be/abc123"python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY" --post"Generate SEO timestamps and post them back to this video: https://youtu.be/abc123"python scripts/youtube_desc_generator.py --url "https://youtu.be/abc123" "$GEMINI_API_KEY" --post"Process this transcript text: 0:00 Welcome..."python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "$GEMINI_API_KEY""Generate timestamps from my transcript text: 0:00 Welcome..."python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "$GEMINI_API_KEY""Process my transcript text and post it to my latest video: 0:00 Welcome..."python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "$GEMINI_API_KEY" --post"Generate timestamps from my transcript and upload to YouTube: 0:00 Welcome..."python scripts/youtube_desc_generator.py --transcript "0:00 Welcome..." "$GEMINI_API_KEY" --post

Decision Rules#

Use these rules to determine which command to run when the intent is ambiguous:

• "latest video" or similar → always use --latest mode
• URL present → always use --url mode
• Transcript text present → always use --transcript mode
• "post", "update", "upload", "push" anywhere in the message → add --post flag (Note: commands like "create timestamps for my latest video" imply updating it, so --post is added)
• No --post → generate and print only, do not touch YouTube
• --transcript --post and --latest --post → always targets the latest upload on the channel
• --url --post → always targets that specific video

Generated Output#

The script returns a single clean block — no labels or extra text:

• SEO-Optimized Timestamps — YouTube chapters starting at 0:00 with keyword-rich labels and SEO suffix tags (e.g. (Tutorial), (Overview), (2026))

Important: Output only the final timestamps. Do not include any introductory sentences, headings, labels, preamble, or commentary before or after the output.

How It Works#

URL mode:

1. Extracts the video ID from the provided YouTube URL
2. Fetches the English transcript via youtube-transcript-api
3. Formats the transcript with MM:SS timestamps
4. Sends a prompt to Gemini for timestamps
5. Prints the timestamps
6. (With --post) Authenticates via OAuth2 and appends the new timestamps to that specific video's description

Transcript mode:

1. Reads the provided raw transcript text string
2. Sends a prompt to Gemini for timestamps
3. Prints the timestamps
4. (With --post) Authenticates via OAuth2, finds your latest upload, and appends the new timestamps to its description

OAuth Setup (for --post only)#

1. Go to Google Cloud Console
2. Create a project and enable the YouTube Data API v3
3. Create OAuth 2.0 credentials (Desktop App type)
4. Download the file as credentials.json and place it in scripts/
5. On first run with --post, a browser window will open for you to authorize access
6. A token.pickle file will be saved automatically for future runs

Troubleshooting#

No transcript available (URL mode):

• The video may have transcripts disabled or no English captions
• Switch to --transcript mode with a manually prepared transcript string

Transcript text not loading (transcript mode):

• Ensure the text format is correct
• Each line should follow MM:SS text format

Gemini API errors:

• Verify your API key is valid and has access to gemini-3.1-flash-lite-preview
• Check your quota at Google AI Studio

--post not updating the video:

• Ensure credentials.json is in the scripts/ directory
• Delete token.pickle and re-authenticate if credentials have expired
• Confirm the YouTube Data API v3 is enabled in your Google Cloud project

Wrong video appended to in transcript mode:

• Transcript mode always targets your most recent upload — make sure the correct video is your latest
• If you need to target a specific video, use --url mode instead

Privacy & Safety#

⚠️ Important: The --post flag will append timestamps to a video's description automatically without manual confirmation in the CLI.

• The script always shows you the target video title being updated
• OAuth credentials are stored locally in token.pickle — keep this file secure
• Revoke access anytime via your Google Account permissions