Rendi runs FFmpeg commands in the cloud, so long encodes finish while nobody is watching. FlowMattic picks up each completed command and tells the right Slack channel or person, with the output link, a review reminder or the file itself. For video teams, podcast editors and developers who batch media jobs.
1 trigger14 actions6 example workflows2 ready-made templatesUnlimited runs
Try a pairing
When this happens in Rendi1 trigger
Do this in Slack14 actions
1. TriggerFFmpeg Command Completed
2. ActionSend Channel Message
When Rendi fires FFmpeg Command Completed, FlowMattic runs Send Channel Message in Slack with the data from that event.
You build this in the FlowMattic workflow builder on your own site. See the setup steps
Rendi and Slack workflows you can build
Each one uses only triggers and actions the two integrations ship today, plus FlowMattic's own tools. Where the library has a ready-made template, import it instead of building from scratch.
Ready-made template
Post a message when an FFmpeg command finishes
The media channel gets the command and its output link as soon as Rendi reports completion, so editors stop refreshing a dashboard to see if the render is done.
A Router reads the output file type in the completion data. Video encodes go to the video team and audio exports to the podcast channel, so each group sees only its own work.
Upload File puts a short output, such as a thumbnail or a trailer cut, straight into the review channel, so feedback happens in the thread next to the file.
FFmpeg Command Completed→Upload File
Message yourself when a long batch encode completes
Freelancers who start a heavy job before leaving the desk get a Slackbot direct message on their phone with the output link and can deliver to the client from there.
FFmpeg Command Completed→Send Direct Message
Set a quality-check reminder for every finished render
Add Reminder asks the editor to watch the output before it is published, a small check that catches a wrong bitrate or a cropped frame before the audience does.
A Counter adds one for each completed command and the channel message carries the total, which helps when a team pushes a season of episodes through in one day.
Post a message when an FFmpeg command finishesTemplate
1. Trigger in Rendi
FFmpeg Command Completed
2. Action in Slack
Send Channel Message
Fields mapped from the earlier steps (a typical setup)
From Rendi
To Slack
Command ID
Message: job
Status
Message: result
Output file URL
Message: download link
Completed at
Message: finished
Built on the FlowMattic canvas. Test each step with real data, then switch the workflow on.
Triggers and actions in this pair
A trigger starts a workflow. An action is something FlowMattic does in the app as a step.
Good to know
Every finished command fires the trigger, including test runs. Add a Filter on a field you control, such as the output file name, if only some jobs should post.
The field names come from Rendi's completion data, so the mapping above is an example. Check the captured test run before building a Router on file type or status.
For large video files, post the output link rather than using Upload File, and keep Upload File for thumbnails, stills and short clips.
Send Channel MessagePost or Schedule a new message to a specific #channel
Add ReminderAdds a reminder for the user
Create ChannelCreates a new channel
List All ChannelsRetrieve list of all channels
Set Channel TopicSets the topic on a selected channel
Set StatusSets your Slack status to the given text and emoji
Invite User To ChannelInvite an existing User to an existing Channel. You must be a member of the channel to invite someone to it
Find User by EmailFinds a user by matching against their email instead of their username
Find User by IDFinds a user by their ID.
Send Direct MessageSend a direct message to a user or yourself from the Slackbot. Can also schedule a message for later
Send Private Channel MessagePost a new message to a private channel you choose. Can also schedule a message for later
Update ProfileUpdate basic profile fields such as name or title
Find MessageFinds a Slack message using the Slack Search feature
Upload FileUpload file to your slack workplace
Why run this pair with FlowMattic
Rendi and Slack connect through FlowMattic on your own site, with no separate automation account in the middle and no charge per run.
Renders announce themselves
Nobody has to watch a long encode. The team hears in Slack when the output is ready and can move to review or delivery.
Review happens next to the file
Uploading short outputs to a review channel keeps comments, approvals and the clip in one thread.
Batch days cost the same
FlowMattic runs on your WordPress site with unlimited runs, so a day with hundreds of completed commands adds no per-task charge.
Common questions
How do I get a Slack notification when a Rendi job finishes?
Create a FlowMattic workflow with the Rendi FFmpeg Command Completed trigger, connect it as the trigger describes, then add Slack Send Channel Message or Send Direct Message with the output link in the text.
Can I post only failed commands?
If the completion data carries a status, add a Filter after the trigger that passes only failed runs, and send those to the developers' channel. Check a captured run to see which status values Rendi sends.
Can the output file appear in Slack instead of a link?
Yes. Use the Upload File action with the output URL from the trigger. It suits stills and short clips. Long, high-bitrate videos are easier to share as a link.
Can one workflow notify more than one team?
Yes. A Router after the trigger can send each completed command down a different path, for example by file type or by a prefix you add to output names, each ending in its own Slack step.
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Reviewed 27 Oct 2026. The example workflows are written with AI from the real triggers and actions of both integrations and checked against them. Rendi integration 1.0.0, Slack integration 1.0.