Build a viral-video watchlist that reports to Claude (/videos-watchlist)
Hey, it's Cindy 🌱 A watchlist is your niche's scoreboard: the creators you study, tracked in one place. This tool makes the scoreboard talk, pulling the top-performing videos across everyone you follow.
btw the waitlist for AI System Club is now open! If you're keen on using AI to automate your content, video editing, job search, business or build AI agents, feel free to sign up (only if you want to hehe). Ps. the waitlist gets first dibs:)
the setup, once
Build the watchlist, connect Claude
In Sandcastles (Pro plan or above), add the creators in your niche to your watchlist first. You can also add profiles through /channels-add after connecting Claude. Then connect the Claude plugin (full walkthrough in the research machine guide) and let Claude do the cross-video pattern reading.
Complete the connection once
Get the account-specific plugin. In Sandcastles, open Settings, then Connectors, then the MCP section and download the plugin ZIP. MCP access requires an eligible paid Sandcastles plan; check the current plan before buying.
Install in Claude Desktop. Open Customize, Plugins, Add, then Upload Plugin. Upload the ZIP. In the plugin page's Connectors area, choose Install, then Add for the prefilled Sandcastles connector.
Authorize your account. Open Customize, Connectors, find Sandcastles (Custom), choose Connect and complete the Sandcastles sign-in. Confirm the connected state before trying the workflow.
Populate a small watchlist. Use /channels-add with a few creator profile URLs and confirm the returned additions. Use /videos-watchlist to fetch a small sample. Ask Claude to list which examples need /analyze, show the proposed credit cost, and wait for your approval before running those analyses. Confirm that transcripts or analysis results exist before asking for topic, hook or format patterns.
Limit permissions and test. Review the connector's tools. Keep approval enabled for paid analysis or changes until you understand the action and credit cost. Ask Claude to list the available Sandcastles tools and read a small sample from your chosen creator or watchlist.
The official Sandcastles setup documents this installation route. Start with a small watchlist and a few analyzed examples. Ask Claude to identify missing inputs and the proposed credit-using analysis before expanding the sample; an empty dataset is not evidence that a niche has no winners.
These slash commands belong to the installed Sandcastles plugin, not native Claude. If a command is unavailable, describe the same request in plain language and ask Claude to use the connected tools. If sign-in fails, check browser pop-up permissions and organization connector restrictions. Do not paste account passwords or API keys into a prompt.
the workflow
Pull the leaderboard
🏆 the watchlist leaderboard prompt
/videos-watchlist Show me the top performing videos from my watchlist in the last 28 days, ordered by views, and include the available engagement rate. If I choose an optional 2 percent engagement floor, label it as my selection preference, not proof of organic reach. Do not infer paid promotion or bought engagement from this metric. For each video give me the link, the creator, the views and the engagement rate.
what comes back
The clean leaderboard
A ranked list from the available watchlist sample: creator handle, views, engagement rate and a direct link per video. Low engagement relative to views does not establish that reach was bought or boosted. Compare similar formats, audiences and reporting windows, and label missing data.
💡 Pro move: feed the top 5 into /analyze one by one, then ask Claude for the shared meta-pattern. Review the examples before treating a shared pattern as a useful hypothesis.