Notice when a signal changes
A removed reaction can merit a second look. Get the message context and a neutral prompt to verify what changed.
Trigger
Message Reaction Removed
Triggered when a reaction is removed from a message in Slack. Supports optional filtering by channel and emoji name.
Action
Create Message
Tool to create a new message completion. use when you need to generate assistant text given a conversation history.
Why this helps
A changed reaction may go unnoticed, leaving uncertainty about whether a previous signal still applies.
- Surfaces the message associated with the removed reaction.
- Avoids assuming the removal reverses a decision.
- Suggests checking the original author or thread when context is unclear.
Setup
Build it in a few focused steps.
- 1Connect Slack and Anthropic administrator once via the portal.
- 2Create a named automation in the portal or describe the outcome to Notis.
- 3In one plain-language prompt, ask for a neutral context summary of the reacted-to message and a reminder to verify changed intent rather than infer it.
- 4Choose Message Reaction Removed, select a run-report channel, and test with one real reaction removal.
Questions about this workflow
Does a removed reaction prove a decision was reversed?
No. The workflow creates a review note and leaves the reason open unless stated.
Can I scope this to a channel or emoji?
The reaction trigger supports optional channel and emoji-name filters.
When this happens · Trigger
Do this · Action
Supported Triggers and Actions
Notis builds workflows that link Slack to Anthropic administrator. A trigger fires from one place; an action lands in another.
Slack triggers
Anthropic administrator actions
Recurring trigger
Notis starts this workflow on a schedule, such as daily, weekly, or during business hours.
Create Message
Tool to create a new message completion. use when you need to generate assistant text given a conversation history.
Webhook trigger
Notis starts this workflow when an external tool or custom backend sends an HTTP request.
Get Model
Tool to retrieve details of a specific model by its id. use after confirming the model id is valid.
New Channel Created Trigger
Triggered when a new channel is created in Slack.
List models
Tool to list available models. use when you need to see which models are available before selection.
Channel Message Received
Triggered when a message is posted in a Slack channel (public, private, or multi-party IM). Does NOT match direct messages.
Prompt Caching
Tool to cache and reuse prompt content to reduce costs and latency. use after you have static prompt portions you intend to reuse across calls.
Direct Message Received
Triggered when a new direct message (DM) is sent to a user in Slack. Catches all DMs across all DM channels.
Message Reaction Added
Triggered when a reaction is added to a message in Slack. Supports optional filtering by channel and emoji name.
Message Reaction Removed
Triggered when a reaction is removed from a message in Slack. Supports optional filtering by channel and emoji name.
Reaction Added Trigger
DEPRECATED: use `SLACK_MESSAGE_REACTION_ADDED` instead. Triggered when a reaction is added to a message in Slack.
Connect any two apps with Notis in the middle.
Slack and Anthropic administrator, or any other combination from 1,000+ integrations.
When this happens · Trigger
Do this · Action
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