Slack (slack)

The slack connector indexes channel messages and the workspace user directory. Messages are grouped into threads so a search hit reopens the whole conversation, not a single isolated line.

How MFS sees it

Each channel exposes a message stream; the workspace has one user directory:

slack://acme/
├── channels/
│   ├── eng-backend__C012345/messages.jsonl   message_stream
│   └── general__C067890/messages.jsonl
└── users.jsonl                                record_collection

Built-in presets mean no [[objects]] config is needed:

• slack.messages groups messages by thread_ts and embeds each thread as one chunk, rendered with speaker identity (U012345: deploy failed) so search has a stronger signal.
• slack.users indexes each member's name, real name, display name, title, and email — so mfs search "VP of Engineering" slack://acme/users.jsonl works.

Message user values are Slack IDs (U…); resolve them to names via users.jsonl.

Credentials

You need a Bot token (xoxb-…, recommended) or a User token (xoxp-…, when the bot can't see what you can).

Bot token — https://api.slack.com/apps → Create New App → From scratch:

1. OAuth & Permissions → add Bot Token Scopes:
   • channels:read, channels:history — list and read public channels
   • users:read — the user directory (users.jsonl)
   • groups:read + groups:history — private channels (optional)
   • mpim:read + mpim:history — group DMs (optional)
2. Install to Workspace → authorize → copy the Bot User OAuth Token (xoxb-…).
3. For each private channel, invite the bot from inside it: /invite @bot. Public channels need no invite once scopes are granted.

A User token (xoxp-…) is created the same way under User Token Scopes; use it when the bot identity can't reach DMs or un-invited channels. It rotates when the user revokes access.

Configuration

token = "env:SLACK_BOT_TOKEN"
channel_types = ["public_channel"]   # + private_channel, mpim, im
oldest = "now-30d"                    # optional history floor
max_read_rows = 50000

Sync and freshness

The connector tracks each channel's latest message ts as its cursor, so re-syncs only fetch newer messages. Slack messages are append-mostly, so deletion detection is never — edited or deleted messages aren't retroactively pruned.

Search and browse

mfs add slack://acme --config ./slack.toml

mfs search "deploy failed" slack://acme/channels/eng-backend__C012345/messages.jsonl
mfs search "Alice Wang" slack://acme/users.jsonl
mfs cat slack://acme/channels/eng-backend__C012345/messages.jsonl --locator '{"thread_ts":"1717123456.001200"}'

Pitfalls

• Private channels need both the scopes and bot membership.
• Hits are thread aggregates, so a short query can reopen a long thread.
• max_read_rows applies per channel and can mark recall partial.