The Best MCP Gateways for Glean in 2026

First, the naming collision: Glean sells its own product called MCP Gateway, and it’s good at its job — exposing “2,000+ governed tools” Glean already reaches outward to clients like Claude, ChatGPT, and Cursor. The verdict on the inbound question — what to plug into Glean: keep Glean’s native governance plane (admin-approved MCP action packs, per-action toggles, group visibility, Glean Protect — and the MCP Gateway for that outbound job), and connect StackOne into Glean as a custom remote MCP server for deep actions on the systems of record Glean’s action catalogs don’t cover — Workday, SAP, UKG, ServiceNow.

This is a companion to our full MCP gateway comparison — read that for the twelve-vendor landscape; read this for the Glean-specific decision.

Does Glean support MCP? Three things to keep straight

Glean’s MCP story has three distinct parts, and most confusion about “an MCP gateway for Glean” comes from blending them.

1. Glean as an MCP host (the subject of this page). End users can invoke third-party MCP tools inside Glean Assistant and Glean Agents — Glean’s docs say remote MCP servers are fully supported in Glean, with beta support in Agents. An admin adds servers under Admin Console → Platform → Actions as an MCP action pack — from a supported template or a custom server URL plus OAuth configuration. Glean discovers the server’s tools; the admin enables them per surface, toggles individual actions, and scopes visibility to user groups. Custom servers can live in your VPC behind allowlisted endpoints. One current constraint: Gemini models are not supported for this flow. (Glean docs, updated June 5, 2026; Glean blog, March 10, 2026)

2. Glean’s own MCP server (Glean as a tool for other agents). Glean exposes Search, Chat, Read Document, Code Search, and People — plus your Glean agents — as MCP tools to 18 documented host apps. Launched in public beta September 4, 2025. (Glean docs, updated June 9, 2026; announcement)

3. Glean’s MCP Gateway (Glean’s governance product). A single MCP endpoint bundling custom tools, external third-party MCP servers, and read/write tools derived from Glean’s connectors — “2,000+ governed tools” — served to Claude, ChatGPT, Cursor, Gemini, Copilot, and Claude Code. (Glean docs, updated June 3, 2026; more in its comparison entry below.)

Note what the Gateway governs: tools Glean already has, exposed outward — a different job from supplying deep new integrations. The question for this page is what fills the catalog behind it.

What Glean’s native catalog and controls don’t cover

Glean’s governance plane is genuinely strong: admins decide which MCP servers and tools are allowed and who uses them in Assistant vs. Agents — “explicitly approved, discoverable, and auditable” (Glean blog, March 2026). Glean Protect scans prompts, retrieved content, and responses with prompt-injection and jailbreak detection; human-in-the-loop confirmation is the default for higher-impact operations, with per-tool always-allow vs. needs-approval settings. None of that needs replacing. Three gaps sit behind it:

The catalog asymmetry. Glean’s site advertises over a hundred search connectors; its actions docs list 12 first-party action packs (Jira, Confluence, Salesforce, Slack, GitHub, Zendesk, Google Workspace, Microsoft 365, Snowflake, Databricks, Calendar Search, Code Writer — as of June 5, 2026). Glean’s March 10, 2026 launch announcement named 17 verified third-party MCP servers, mostly collaboration and product SaaS (Amplitude, Asana, Atlassian, Box, Canva, ClickUp, GitHub, HubSpot, Intercom, Linear, Lucid, Monday, Notion, PagerDuty, ThoughtSpot, Udemy, WisdomAI), and the docs’ supported remote MCP servers list has since grown to 176 (updated June 1, 2026) — mostly each vendor’s own server, NetSuite’s among them. But a supported vendor server is connectivity, not necessarily deep agent-grade action coverage: vendor-run servers vary widely in auth model and action depth. And Workday, SAP, UKG, and ServiceNow appear nowhere — not as action packs, not as verified templates, not on the supported list. Glean can find the answer in those systems; out of the box it largely can’t act on them.

Write-action auth is a different mechanism than search permissions. Glean’s celebrated permission inheritance comes from crawled, indexed ACLs — and it applies to search. MCP actions use credential pass-through instead. Glean’s actions overview is clear: “If your account cannot perform an operation in a tool such as Jira, Salesforce, or Google Workspace, Glean cannot do it via an action” — and its March 2026 announcement adds that “Every MCP action runs under the end user’s identity and permissions.” True — in OAuth User mode. But Glean supports five auth modes — None, OAuth Admin, OAuth User, API Key, OAuth Client Credentials — and OAuth Admin shares a single admin credential across all users, trading away per-user permissions by design. (Glean supports PKCE and doesn’t require dynamic client registration, so MCP servers with pre-registered OAuth clients work.) Not a flaw — a configuration choice to make deliberately, and it means the MCP server you connect must support per-user authorization to use the good mode.

Custom non-MCP actions are deliberately constrained. Glean’s custom actions take an OpenAPI spec but support a single endpoint with flat fields only — no nested objects, enums for fixed values. Fine for a webhook; not how you express “create a requisition in Workday.” MCP is the richer path into Glean — which is why the server behind it matters.

What to look for in an MCP gateway for Glean

Each criterion below maps to a verified Glean constraint:

The best MCP gateways for Glean, compared

The comparison question is not “Glean’s MCP Gateway vs. the rest” — it’s what do you put behind or inside Glean to act on systems of record. Glean’s own Gateway sits in the table as the native baseline. Of the twelve gateways in our full comparison, only managed gateways that run as a hosted remote MCP server with OAuth — the shape Glean’s action-pack flow accepts — make the cut here; self-hosted routing gateways like Microsoft’s or Docker’s govern servers you’d still have to build and run yourself, and if your shortlist includes Workato or Merge, the hub covers how they compare.

Glean MCP Gateway

What is Glean’s MCP Gateway? It’s the right governance plane for outbound tool exposure — tools Glean already reaches: one endpoint exposing custom tools, approved external MCP servers, and connector-derived read/write tools to Claude, ChatGPT, Cursor, Gemini, Copilot, and Claude Code — with Protect+ guardrails, per-user tool visibility controls, and an MCP Insights dashboard (per Glean’s documentation, June 3, 2026; Glean doesn’t publish a GA/beta status for it). If your goal is “let employees use Glean’s tools from outside clients, governed,” this is the product; nothing in this comparison replaces it. Its boundary is its catalog: the tool supply is Glean’s connector-derived tools plus the action packs and supported servers above — which is precisely where an external gateway slots in, registered through the Admin Console’s MCP action pack flow and governed by the same admin approvals.

Best for: Glean customers extending Glean’s own capabilities to external AI clients under one governed endpoint.

1. StackOne

StackOne is the enterprise layer for AI agents to safely act on any application — 310+ managed connectors exposing 20,000+ agent-optimized actions across HRIS, ERP, CRM, and ITSM. Depth is verifiable per system: Workday has 128 actions, Salesforce 380, Jira 147.

Against the Glean criteria: it connects as a managed remote MCP server with OAuth — the hosted shape Glean’s action-pack flow accepts; its OAuth 2.1 end-user flow means you can run Glean’s OAuth User mode — every action executes as the actual employee, with per-user linked accounts rather than a shared admin credential; admins scope which actions each project exposes, so Glean admins triage a curated list, not raw API wrappers; request logs capture every call down to the underlying provider requests, complementing Glean’s MCP Insights; and StackOne Defender scans tool responses for prompt injection before they return (89.0% detection accuracy in our published evaluation) — a layer in front of Glean Protect’s scanning, not a replacement for it.

Limitation: the catalog focuses on business systems, not consumer applications — for the consumer-app long tail, Zapier’s catalog is far bigger. When a system isn’t in the catalog, the AI Connector Builder builds or extends a connector on the same engine that powers the pre-built ones, so coverage isn’t capped at what ships out of the box.

Best for: Glean customers whose agents need governed, deep actions on systems of record that Glean’s catalogs don’t reach.

2. Composio

Composio markets 1,000+ toolkits and 20,000+ tools via MCP or direct APIs, with per-user connected accounts where end users authorize via a hosted Connect Link — compatible in principle with Glean’s OAuth User mode — and published developer-friendly pricing (free tier, then from $29/month). It’s genuinely developer-loved: good SDKs, fast setup. The open question for a Glean deployment is the org-level control plane: as of June 9, 2026 we couldn’t find central policy enforcement and approval workflows in its public docs — Glean’s approvals cover the Glean side, but IT-led reviews will want governance on the gateway side too. Breadth also skews developer-SaaS rather than the ERP/HRIS tier.

Best for: developer-led Glean teams wiring up agent tooling quickly, ahead of organizational governance requirements.

3. Zapier MCP

Zapier MCP brings the largest catalog in this comparison — 9,000+ apps and 30,000+ pre-built actions — to any MCP client, Glean included, riding on auth infrastructure refined over 13+ years. The caveats from our hub comparison apply with extra force inside Glean: each MCP tool call consumes two tasks from your plan quota, and agent loops are chatty; actions are built for automation triggers — broad rather than deep, fine for “post to Slack,” thinner for “run this filtered Workday report”; and since Glean admins enable tools per action, an automation-shaped catalog means more triage. For the consumer long tail Glean’s supported-server list doesn’t touch, though, Zapier covers far more apps than anything else in this comparison.

Best for: Glean teams adding long-tail app coverage at pilot volumes, especially if already paying for Zapier.

How do you connect Glean to an MCP server?

The flow below uses StackOne as the worked example; every Glean-side step is Glean’s documented MCP action pack flow and applies to any custom remote MCP server.

1. Get the MCP URL from the gateway first. In StackOne, create a project, connect the systems you want to act on (Workday, SAP, ServiceNow), and scope the exposed actions with a connector profile — the project’s MCP URL (per StackOne’s docs) is what you’ll paste into Glean.
2. In the Glean Admin Console, go to Platform → Actions and add an MCP action pack with that URL, selecting OAuth User mode so every action runs under the end user’s identity.
3. Glean discovers the server’s tools per its documented flow. Because the surface is curated by the connector profile from step 1, the admin sees a scoped, named action list rather than an unfiltered API surface.
4. Enable per surface and scope visibility. Turn the pack on for Assistant (GA) and, if you’re in the beta, Agents; toggle individual actions; restrict visibility to the groups that need it (HR ops gets Workday actions, IT gets ITSM).
5. Users authorize on first use. The first time an employee invokes a StackOne tool, they complete StackOne’s OAuth 2.1 end-user flow — sign in through SSO, approve a consent screen branded for your organization, opt in the specific linked accounts. From then on, actions run as them, Glean’s approval prompts apply per tool, and Glean’s MCP Insights plus StackOne’s request logs record the trail.

The admin sees one action pack, a curated tool list with per-action toggles, group-scoped visibility. The end user sees new tools in Assistant, a one-time consent screen, and Glean’s normal approval prompts on higher-impact operations.

When you don’t need an MCP gateway for Glean

• Your action needs fit Glean’s catalogs. If Jira, Salesforce, Slack, GitHub, Zendesk and the supported-server list cover what your agents must do, Glean’s native action packs are simpler — use them.
• You only need Glean’s tools in other clients. Exposing Glean search/chat/agents to Claude or Cursor is exactly what Glean’s own MCP Gateway is for. Don’t buy a second product for that job.
• You’re still proving the use case. Connect a single managed MCP server for the one system that matters, prove value in Assistant, then graduate when more systems and users make governance real.

The trigger point: the first time someone asks Glean to change something in Workday, SAP, UKG, or ServiceNow — and the assistant that can find anything can’t touch it.

StackOne is the governed layer between AI agents and 310+ enterprise systems with 20,000+ agent-optimized actions — over MCP, A2A, API, and SDKs — with end-user OAuth linking, connectors you can extend, and built-in prompt-injection defense. See pricing or book a demo.

Related: The Best MCP Gateways in 2026, Compared · StackOne MCP · Workday MCP · Salesforce MCP · Jira MCP

More MCP gateway guides

Every guide in this series applies the same disclosed criteria to a different AI client. Start with the full comparison, or jump to yours: