# Add Microsoft Teams chat message reaction

Canonical URL: https://docs.fuse.init.inc/integrations/microsoft-teams/actions/chat_messages.reactions.add

Add a reaction to a chat message.

Action ID: `chat_messages.reactions.add`
Provider: Microsoft Teams (`microsoft_teams`)
Contract version: 1

## Risk and exposure

- Risk: Write
- Idempotency: Safe — Safe to retry without coordination; repeats do not create additional side effects.
- Availability: Default
- Exposure: REST, SDK, MCP
- MCP hints: readOnly=false, destructive=false, idempotent=true, openWorld=true

## Required scopes

- `ChatMessage.Send`

## Input schema fields

- `chat_id`
- `message_id`
- `reaction`

## Output schema fields

None.

Provider overview: https://docs.fuse.init.inc/integrations/microsoft-teams
Actions index: https://docs.fuse.init.inc/integrations/microsoft-teams/actions
Exact canonical JSON contract: https://docs.fuse.init.inc/api/catalog/v1/providers/microsoft_teams/actions/chat_messages.reactions.add
Deployment-effective discovery: https://api.fuse.init.inc/v1/tenants/%7Btenant_id%7D/providers/microsoft_teams/actions