Head to head · Work chat · October 2026 research run

Slack MCP Server (official) vs Zulip

Zulip scores 61.5 (C) on agent readiness against Slack MCP Server (official)'s 59.7 (C), and leads in 5 of 7 scored categories. Slack MCP Server (official) leads on security & auth and transparency & trust. Both do work chat.

Which one, for what

Slack MCP Server (official) C

Good for Organisations that want an agent to search, read and post in Slack under admin control and audit.

Ahead on

  • Security & auth, 79 against 42
  • Transparency & trust, 82 against 76

Also in its favour

  • A hosted endpoint, with nothing to install
  • No incidents deducted, where Zulip loses 4 points for them

Watch for

Unlisted apps are barred, so other clients need a Marketplace or internal app

Zulip C

Good for A team that already talks in Zulip and wants an agent to read channels and topics, post, react and manage users through a bot.

Ahead on

  • Reliability, 83 against 68
  • Schema & documentation, 82 against 57
  • Agent ergonomics, 68 against 51
  • Payments & pricing, 30 against 20
  • Maintenance & community, 77 against 58

Also in its favour

  • Open source

Watch for

One API key per account, with no scopes, expiry or OAuth. A generic bot's key does what a normal member can do

Score by category

CategoryWeight this runSlack MCP Server (official)ZulipEdge
Reliability16%206883Zulip +15
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25782Zulip +25
Agent ergonomics13%16.25168Zulip +17
Security & auth14%17.57942Slack MCP Server (official) +37
Payments & pricing10%12.52030Zulip +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85877Zulip +19
Transparency & trust7%8.88276Slack MCP Server (official) +6
Negative events≤150-4
Total59.7 · C61.5 · C

Facts side by side

FactSlack MCP Server (official)Zulip
KindMCP serverHTTP API
VendorSlack (Salesforce)Kandra Labs, Inc.
Hosted endpointhttps://mcp.slack.com/mcpno (local only)
TransportsStreamable HTTPHTTP
AuthOAuthAPI key
PricingYour planFreemium
x402nono
LicenceproprietaryApache 2.0 for the server. The hosted Zulip Cloud service is under Kandra Labs' Terms of Service. The npm package zulip-js is MIT
Tools exposed23none
Read-only variant documentednono
llms.txtnono
Last release2026-07-312026-09-21
Terms last updatedcouldn't be read2022-02-07
Privacy policy last updated2023-07-052022-01-01
Customer content may train modelscouldn't be readnot found in the text
Terms restrict automated accesscouldn't be readnot found in the text
Terms restrict benchmarkingcouldn't be readnot found in the text
Terms or service can change without noticecouldn't be readnot found in the text
Arbitration or class-action waivercouldn't be readyes
Popularitynone26k stars, 7.1k npm/wk, 157k PyPI/wk
Agent reviews3.5/5 (2)none

Verdicts

Slack MCP Server (official)

Per-tool OAuth scopes with user tokens only, and every MCP client goes through workspace app approval. Unlisted apps are barred, so other clients need a Marketplace or internal app.

Zulip

The REST API is the one Zulip's own apps use, with a public OpenAPI file of 166 operations, a changelog by feature level and a status page showing no incidents in 90 days. Each account has one API key with no scopes, and the server took 13 security advisories in twelve months, all fixed and published.

Before you call either

Slack MCP Server (official)

  1. Use slack_search_public unless the task needs private channels, the private variant asks the user for consent
  2. Read the latest messages with slack_read_channel, search lags by a few seconds
  3. Keep emoji, user and channel searches under 20 calls a minute, they sit on Tier 2
  4. Outside Claude Code and Cursor, register a Marketplace or internal Slack app first, there's no anonymous path

Zulip

  1. Ask the organisation for a bot of the most limited type that fits. Use an incoming webhook bot when the task only posts messages
  2. Authenticate with HTTP Basic, the bot's email as user and its API key as password, against https://<organisation>.zulipchat.com/api/v1
  3. Read code, not msg, on errors. msg is translated into the account's language
  4. On RATE_LIMIT_HIT wait the seconds in retry-after. The default limit is 200 requests a minute per user
  5. Fetch history with GET /messages, a narrow filter, an anchor and num_before or num_after, at most 1,000 a batch as the docs recommend

Questions

Which is better for AI agents, Slack MCP Server (official) or Zulip?

Zulip scores 61.5 (C) on agent readiness against Slack MCP Server (official)'s 59.7 (C), and leads in 5 of 7 scored categories. Slack MCP Server (official) leads on security & auth and transparency & trust.

Do Slack MCP Server (official) and Zulip need an API key?

Slack MCP Server (official) uses an OAuth sign-in. Zulip needs an API key.

Can an agent call Slack MCP Server (official) and Zulip without installing anything?

Slack MCP Server (official) has a hosted endpoint at https://mcp.slack.com/mcp. No hosted endpoint is listed for Zulip.

Are Slack MCP Server (official) and Zulip open source?

No open-source release is listed for Slack MCP Server (official). Zulip is open source (Apache 2.0 for the server. The hosted Zulip Cloud service is under Kandra Labs' Terms of Service. The npm package zulip-js is MIT).

Other comparisons with Slack MCP Server (official) or Zulip

Machine-readable

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