Slack vs iMessage History
Slack is a plugin bundle for AI coding tools published by Salesforce. Marketplaces we read that list it: 1 (Claude: knowledge-work-plugins). iMessage History is an MCP server published by anipotts. Marketplaces we read that list it: 3 (Official MCP Registry, npm registry (MCP servers), Community GitHub marketplaces). As of our marketplace pass on 2026-10-20. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace |  Slack |   iMessage History |
|---|---|---|
| Claude: knowledge-work-plugins | Listed Version: 1.0.0 Forks (GitHub): 3 458 Stars (GitHub): 30 632 Not marked · First seen |
Not listed |
| Official MCP Registry | Not listed | Listed Version: 3.2.0 Downloads/month (npm): 1 951 Downloads/week (npm): 147 Forks (GitHub): 7 Stars (GitHub): 27 Not marked · First seen |
| npm registry (MCP servers) | Not listed | Listed Version: 3.2.0 Downloads/month (npm): 1 951 Downloads/week (npm): 147 Forks (GitHub): 7 Stars (GitHub): 27 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | Slack | iMessage History |
|---|---|---|
| Marketplaces that list it (differs) | 1 (worse) | 3 (better) |
| Stars (GitHub) (differs) | 30 632 (better) | 27 (worse) |
| Forks (GitHub) (differs) | 3 458 (better) | 7 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | Remote server (mcp.slack.com/mcp) | On your machine (imessage-mcp) |
| Transport (differs) | Streamable HTTP | stdio |
| Tools it declares | Not published | Not published |
| Environment variables it asks for (differs) | Not published | 5, secrets among them: 0 |
| Parts of the bundle (differs) | 8 | 1 |
| Licence | MIT | MIT |
| Repository (differs) | github.com/anthropics/knowledge-work-plugins | github.com/anipotts/imessage-mcp |
| Changes in the last 7 days | 0 | 0 |
| First seen | 2026-10-11 | 2026-10-11 |
| Endpoint at the last check (differs) | Responded 4 days ago, requires a key | no remote endpoint we check |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
Slack
Slack integration for searching messages, sending communications, managing canvases, and more
iMessage History
Search and read your Apple Messages history from any MCP client. Read-only, local.
How to run each
Slack As a Claude Code plugin
/plugin marketplace add anthropics/knowledge-work-plugins
/plugin install slack-by-salesforce@knowledge-work-pluginsiMessage History As a local MCP server: npm package
claude mcp add --transport stdio imessage-mcp -- npx -y imessage-mcpCommands built only from what the marketplaces declare; the full set for every client is on each card.
Only Slack has a remote endpoint we check. How we check endpoints
Tools each declares
Neither one's marketplaces publish a list of tools, so there is nothing to compare.
Settings each asks for
The marketplaces of Slack publish no settings it asks for, so we do not compare settings.
What it can do: Slack · What it can do: iMessage History · Compare two other plugins
Data comes from the public marketplace file https://github.com/anthropics/knowledge-work-plugins/blob/HEAD/.claude-plugin/marketplace.json. Data comes from the Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Package data comes from the public npm registry (registry.npmjs.org). Data comes from public marketplace files in GitHub repositories of their authors. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.