DownloadThisVideo

Easily download videos/GIFs off Twitter. Mention the bot (@this_vid) in a reply to the tweet containing the video, and it'll reply with a download link in a few minutes.

How this works

Stack

• AWS Lambda with the Serverless Framework
• AWS SNS
• Redis
• Node.js

Implementation

The bot consists of several AWS Lambda functions that work in tandem:

fetchTweetsToDownload

This function runs every 4 minutes and checks for new mentions. It publishes these new mentions as a new notification on an SNS topic. The 4-minute interval is so as to not hit Twitter's rate limits and minimize AWS Lambda usage time, while being near-realtime.

sendDownloadLink

This is triggered by new notifications on the SNS topic. It:

• processes the tweets in the message body,
• calls Twitter's API to retrieve media links. Any video links retrieved for a tweet are stored in Redis for faster repeated access (other users requesting the same video).
• adds the download details to the user's store in Redis. The user's store is an entry in Redis where all downloads requested by a user are cached for a certain period (48 hours).
• attempts to reply to the user with a link to the user's download page (see section below). "Attempts" because Twitter enforces tweet limits (2400 per day, counted in 15-minute periods). If the API limits have been reached, the bot will "cool down" (not send any replies) for 10 minutes.

getDownloads

This is triggered by a HTTP request to the / (for instance, http://thisvid.space/jack). It renders a page showing a list of the user's recent downloads.

getHomePage

Renders the homepage 😁. See http://thisvid.space.

retryFailedTasks

This re-publishes failed tasks (stored in Redis) as a new SNS message. For now, it can only be triggered manually.

Supporters

These folks help to keep this running. If you've benefited from this work and would like to help keep it running, consider supporting me on Patreon.

• Sharee
• Luca Turgut
• Xavier Brown