bridge: add 👀 on receive and ✅ on reply emoji reactions

[benvinegar]

Brings back the attentive emoji behavior:

• :eyes: on receive — immediately when a valid user message arrives from Slack, before forwarding to the agent
• :white_check_mark: on reply — when the agent sends its first reply back to the same thread (via /send or /reply)

Both bridges (broker-pull and legacy Socket Mode) implement identical behavior. Pending ack reactions are tracked in a map keyed by channel:thread_ts and auto-expire after 10 minutes. All reactions are fire-and-forget — failures are logged as warnings but never block message delivery or agent forwarding.

Changes

• slack-bridge/broker-bridge.mjs — added pendingAckReactions map, resolveAckReaction() helper, 👀 in handleUserMessage, ✅ in /send and /reply endpoints
• slack-bridge/bridge.mjs — same pattern using Slack Web API directly
• test/broker-bridge.integration.test.mjs — updated fire-and-forget test to expect and verify the 👀 reactions.add call

[greptile-apps]

Greptile Summary

Restores emoji reaction feedback for Slack users by adding 👀 immediately when messages arrive and ✅ when the agent replies. Both bridge implementations (broker-pull and Socket Mode) use identical fire-and-forget reaction logic with 10-minute auto-expiry. The implementation tracks pending reactions by channel:thread_ts, which means multiple user messages in the same thread will only result in the last message receiving a checkmark.

Confidence Score: 4/5

• Safe to merge with minor edge case in multi-message threads
• Implementation is clean, follows fire-and-forget pattern correctly, includes proper error handling, and has test coverage. The thread-keying behavior means only the last message in a thread gets ✅ before reply, which may or may not be intentional but doesn't break functionality
• No files require special attention

Important Files Changed

Filename	Overview
slack-bridge/broker-bridge.mjs	Added emoji reaction tracking with 👀 on receive and ✅ on reply; implementation has a minor edge case where multiple messages in same thread before reply will only mark the last one
slack-bridge/bridge.mjs	Mirrors broker-bridge.mjs emoji reaction pattern using Slack Web API directly; shares same thread-keying behavior

_{Last reviewed commit: df00a0a}

[greptile-apps]

_{3 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

if a user sends multiple messages in the same thread before the agent replies, only the last message gets ✅ (each message overwrites the previous entry since they share the same channel:thread_ts key). consider whether this is intentional or if individual messages should be tracked using channel:messageTs as the key instead

Prompt To Fix With AI

This is a comment left during a code review.
Path: slack-bridge/broker-bridge.mjs
Line: 737-742

Comment:
if a user sends multiple messages in the same thread before the agent replies, only the last message gets ✅ (each message overwrites the previous entry since they share the same `channel:thread_ts` key). consider whether this is intentional or if individual messages should be tracked using `channel:messageTs` as the key instead

How can I resolve this? If you propose a fix, please make it concise.

[benvinegar]

Intentional — the ✅ signals "the agent replied to this thread", not "the agent processed this specific message." Each individual message already gets its own 👀 on arrival, so you can tell which ones were seen. Putting ✅ on every queued message in a burst would look noisy.

_{Responded by pi using anthropic/claude-sonnet-4-20250514.}

[greptile-apps]

same threading behavior as broker-bridge: multiple messages in one thread before agent reply will only mark the last one with ✅

Prompt To Fix With AI

This is a comment left during a code review.
Path: slack-bridge/bridge.mjs
Line: 308-313

Comment:
same threading behavior as broker-bridge: multiple messages in one thread before agent reply will only mark the last one with ✅

How can I resolve this? If you propose a fix, please make it concise.

[benvinegar]

Same answer as the broker-bridge comment — this is intentional. 👀 marks each individual message, ✅ marks the thread as responded-to. Only the most recent message in a burst gets the checkmark, which avoids visual noise.

_{Responded by pi using anthropic/claude-sonnet-4-20250514.}