Turning a week of Slack into HeyGen videos with Claude Cowork

HeyGen, whose service renders videos of a digital avatar speaking a script, published a guide to turning a week of a team's Slack messages into a short on-camera update with Anthropic's Claude. Claude reads the channel through a Slack connector, groups the messages by topic, pitches three video ideas and writes a script for the one the user picks. It then passes the script to HeyGen's MCP connector, which renders it with the user's own avatar and voice in their HeyGen account. The user makes two decisions: which story to tell, and when to generate.

The guide calls this Claude's Cowork mode. HeyGen says Anthropic folded Cowork into Claude on September 16, 2026, so there is one Claude window that decides for itself whether a request needs a quick answer or work across files, folders and connected apps. Simon Willison covered the merge the same day. HeyGen plugs in through the same open MCP standard that Slack, Notion and Google Drive connectors use, and the user signs in on HeyGen's own page instead of pasting an API key. HeyGen also advises switching on only the connectors a job needs, because every active connector's tool list sits in Claude's context and more tools make it likelier the agent reaches for the wrong one.

Most of the guide is about making the routine repeatable without handing over the final decision. Because Cowork does not carry anything from one session to the next on its own, HeyGen suggests a project folder with a short instructions file that Claude reads before every run, fixing the voice, length and avatar plus two rules: never invent a number, and never generate until told. Length is set by word count rather than seconds. HeyGen says avatars read roughly 2.5 to 3 words a second, and the presenter in its demo read 67 words in 22.5 seconds. The pitch step can be scheduled to run in the cloud, but HeyGen says the render should stay a separate manual message. It is the only step that spends HeyGen credits, and a scheduled job reads everything in the channel, including half-finished threads, so a debate still in progress can read like a decision.