agy-slack

Slack, with manners, for Google Antigravity and Gemini CLI v0.59.

Names instead of IDs. Confirm before send. One command to install.

npx github:salahuddinuqaili/agy-slack install --client antigravity
gemini extensions install https://github.com/salahuddinuqaili/agy-slack

In Antigravity CLI type /mcp, reload, then:

Catch me up on #eng from this morning.

That’s the whole product. Fifteen agent-native tools, not two hundred raw Slack methods.

Pick a path

export SLACK_USER_TOKEN=xoxp-...
npx github:salahuddinuqaili/agy-slack \
  install --client antigravity

Then /mcp → reload.

gemini extensions install \
  https://github.com/salahuddinuqaili/agy-slack

Then /mcp. Slash commands: /slack:catchup.

npx github:salahuddinuqaili/agy-slack demo

Ask: What did Maya ship today?

Antigravity: serverUrl

Gemini v0.59: httpUrl

npx github:salahuddinuqaili/agy-slack \
  serve --http --port 8787

User token (xoxp-) is strongly recommended so search and DMs work. Bot token (xoxb-) is enough to post as the app in channels it has joined.

Related MCP server: Slack MCP Server

Gemini CLI v0.59 — step by step

Gemini CLI is not Antigravity. It reads ~/.gemini/settings.json. HTTP is httpUrl. Copying an Antigravity snippet will not load the server.

1. Confirm the CLI

gemini --version

Need 0.59.0 or newer. Install from google-gemini/gemini-cli if missing.

2. Create a Slack user token

At api.slack.com/apps generate a user token (xoxp-). Search and DMs require it. Suggested scopes: search:read, channels:history, groups:history, im:history, mpim:history, channels:read, users:read, chat:write.

3. Install the Gemini extension (preferred)

gemini extensions install https://github.com/salahuddinuqaili/agy-slack

Paste SLACK_USER_TOKEN when prompted (keychain). Leave safety mode as confirm. If the extension is disabled:

gemini extensions enable agy-slack

4. Trust the folder

v0.59 fails closed on untrusted workspaces and filters mcpServers. Accept the trust prompt or the server shows as Disconnected.

5. Reload and verify

Restart Gemini, or type /mcp in the TUI:

gemini mcp list

You should see agy-slack connected. The name is hyphenated on purpose (agy_slack breaks Gemini’s tool policy parser).

6. First prompt

Catch me up on #eng from this morning.

Or slash commands: /slack:catchup · /slack:standup · /slack:search · /slack:draft · /slack:who.

A send is previewed. Confirm in Gemini’s tool gate, then again with confirm=true.

Without the extension

export SLACK_USER_TOKEN=xoxp-...
npx github:salahuddinuqaili/agy-slack install --client gemini

gemini mcp add -s user \
  -e SLACK_USER_TOKEN=$SLACK_USER_TOKEN \
  -e SLACK_MCP_MODE=confirm \
  --timeout 60000 \
  agy-slack npx -- -y github:salahuddinuqaili/agy-slack

-- is required so -y goes to npx. Full notes: docs/GEMINI.md.

VS Code + Copilot — step by step

VS Code is not Cursor. Root key is servers, HTTP is { "type": "http", "url" }, secrets are ${input:…}. MCP tools only run in Copilot Agent mode.

1. Install

npx github:salahuddinuqaili/agy-slack install --client vscode

2. Start

Command Palette → MCP: List Servers → Start agy-slack. Trust it. Paste the xoxp- token when prompted (stored by VS Code, not in the JSON).

3. Agent mode

Open Copilot Chat → mode dropdown → Agent. Ask: Catch me up on #eng from this morning.

Project-only: install --client vscode --workspace . writes .vscode/mcp.json. Full notes: docs/VSCODE.md. Example: examples/vscode.mcp.json.

Verify the install:

npx github:salahuddinuqaili/agy-slack doctor --demo

What the model actually calls

Resources: slack://workspace · slack://channels · slack://unreads · slack://me

Prompts: catch_up · standup · find_decision · draft_reply · incident_brief

Names, not IDs

These are all valid channel values:

#eng
eng
C0ENG
@maya
https://northstar-labs.slack.com/archives/C0ENG/p1757416260123456

Time windows for since / latest: today, yesterday, monday, 4h, 90m, 7d, 1w, last 4h, ISO dates, unix seconds.

Resolution is tested in CI against 1,000 colliding users — unicode (José, Søren, 李伟), fifty people named Alex, deleted accounts, dotted handles (j.smith.0), O'Briens, and prefix traps (ann / anna / annabelle).

• Exact @handle, email, and U-id always win.

• ann does not steal annabelle.

• @Alex with fifty Alexes returns the candidates instead of messaging a random one.

• Deleted people are skipped unless you pass their U-id.

• Allow lists accept #eng and @maya.

Safety

SLACK_MCP_MODE is the rail Antigravity Ask mode actually needs.

flowchart LR
  You -->|ask| Agent
  Agent -->|slack_send| Preview
  Preview -->|nothing posted| You
  You -->|approve + confirm=true| Agent
  Agent -->|post| Slack

Optional rails:

SLACK_MCP_ALLOW_CHANNELS=#eng,#incidents,@maya
SLACK_MCP_DENY_CHANNELS=#all-hands

Tokens are never logged. slack_doctor redacts them.

User-token scopes that make the full catalog work:

channels:history channels:read channels:write
groups:history groups:read groups:write
im:history im:read im:write
mpim:history mpim:read mpim:write
chat:write reactions:write
search:read
users:read users:read.email users.profile:write
files:write pins:write pins:read

Invite the bot to any private channel it should see (/invite @your-app).

This project does not use browser session tokens (xoxc / xoxd). That's a ToS risk and a trust problem for an MCP that sits on your agent.

Why this exists

Slack already has an official hosted MCP, and there are community servers that wrap 200+ raw Web API methods. Neither is a good fit for Antigravity.

Antigravity CLI reads ~/.gemini/config/mcp_config.json (and workspace .agents/mcp_config.json), uses serverUrl (not url) for HTTP, and runs MCP tools in Ask mode by default. agy-slack is built around that.

Other clients

npx github:salahuddinuqaili/agy-slack install --client vscode
npx github:salahuddinuqaili/agy-slack install --client claude
npx github:salahuddinuqaili/agy-slack install --client cursor
npx github:salahuddinuqaili/agy-slack install --client all

SDK agents can attach the same process via McpStdioServer — see examples/sdk_agent.py.

Withhold writes without an env change:

{
  "mcpServers": {
    "agy-slack": {
      "command": "npx",
      "args": ["-y", "github:salahuddinuqaili/agy-slack"],
      "disabledTools": [
        "slack_send", "slack_edit", "slack_delete",
        "slack_react", "slack_upload", "slack_create_channel",
        "slack_status"
      ]
    }
  }
}

Full notes: docs/ANTIGRAVITY.md · docs/AUTH.md · SECURITY.md

Development

git clone https://github.com/salahuddinuqaili/agy-slack
cd agy-slack
npm install
npm test          # includes the 1000-user resolution suite
npm run typecheck
npm run build
node dist/index.js doctor --demo

Node 20+. MIT licensed. Not affiliated with Slack, Salesforce, or Google.

License

MIT © Salahuddin Uqaili