on user_shares_media(url_or_file):

    # PATTERN 1: YouTube Video Ingestion
    if media.type == "youtube":
        # Step 1: Get FULL transcript with speaker diarization
        #   WHO said WHAT -- not just a wall of text
        #   Use Diarize.io or equivalent service
        transcript = diarize(video_url)  # speaker-attributed transcript
        # NEVER use YouTube's auto-generated summary or AI summary

        # Step 2: Agent writes OWN analysis (this is the value)
        #   NOT a summary. NOT regurgitation. The agent's TAKE:
        #   - What matters and why (given the user's worldview)
        #   - Key quotes attributed to specific speakers
        #   - Connections to existing brain pages
        #   - Implications and follow-up angles
        analysis = agent_analyze(transcript, user_context)

        # Step 3: Create brain page
        slug = f"media/youtube/{video_slug}"
        modusbrain put <slug> --content """
            # {title}
            **Channel:** {channel} | **Date:** {date} | **Link:** {url}

            ## Analysis
            {agent_analysis}

            ## Key Quotes
            - **{Speaker}** ({timestamp}): "{quote}" -- {why_it_matters}

            ---
            ## Full Transcript
            {diarized_transcript}
        """

        # Step 4: Extract and cross-reference entities
        for person in transcript.mentioned_people:
            modusbrain add_link <slug> <person_slug>
            modusbrain add_link <person_slug> <slug>
            modusbrain add_timeline_entry <person_slug> \
                --entry "Discussed in {video_title}: {what_was_said}" \
                --source "YouTube: {url}"

    # PATTERN 2: Social Media Bundles
    elif media.type == "tweet" or media.type == "social":
        # Don't just save a tweet -- reconstruct FULL context
        bundle = {
            "original": fetch_tweet(url),
            "thread": reconstruct_thread(url),        # quoted tweets, replies
            "linked_articles": fetch_linked_urls(),    # fetch and summarize
            "engagement": get_engagement_data(),       # what resonated
        }

        slug = f"media/social/{platform}-{author}-{date}"
        modusbrain put <slug> --content """
            # {author}: {topic}
            {agent_analysis_of_full_bundle}

            ## Thread
            {reconstructed_thread}

            ## Linked Articles
            {article_summaries}

            ---
            ## Raw
            {original_tweet_text}
        """

        # Extract entities and cross-reference
        for entity in bundle.mentioned_entities:
            modusbrain add_link <slug> <entity_slug>
            modusbrain add_link <entity_slug> <slug>

    # PATTERN 3: PDFs and Documents
    elif media.type == "pdf" or media.type == "document":
        # OCR if needed (scanned PDFs)
        content = ocr_if_needed(file) or extract_text(file)

        # For books and long-form:
        slug = f"sources/{document_slug}"
        modusbrain put <slug> --content """
            # {title}
            **Author:** {author} | **Date:** {date}

            ## Chapter Summaries
            {per_chapter_summary}

            ## Key Quotes
            - p.{page}: "{quote}" -- {why_it_matters}

            ## Cross-References
            {links_to_brain_pages_for_people_and_concepts}

            ---
            ## Source
            {full_text_or_key_sections}
        """

        for entity in document.mentioned_entities:
            modusbrain add_link <slug> <entity_slug>
            modusbrain add_link <entity_slug> <slug>

    # Always sync after ingestion
    modusbrain sync