This spotlight is part of our MCP company spotlights, within The MCP Guide. Building an MCP company? See SEO and GEO for MCP companies.
Fern builds developer documentation sites and SDKs from API definitions. It generates and hosts an MCP server for docs sites that use its Ask Fern AI search. Readers' AI tools can then get answers from your docs.
Checked against: Fern's MCP server documentation on 28 October 2026. eSEOspace did not test Fern's products.
Key Takeaways
- Fern hosts an MCP server at
/_mcp/serveron every docs site with Ask Fern enabled. - The hosted server has one tool that answers questions using Ask Fern's retrieval pipeline.
- Each message costs 2 AI credits; the free plan includes 250 credits a month.
- Self-hosted Fern containers serve a different, credit-free server with search and page-fetch tools.
- Fern's site footer describes it as "a Postman company."
At a glance
| Item | Details |
|---|---|
| Company | Fern (Birch Solutions, Inc.), "a Postman company" per its footer |
| What it offers for MCP | Hosted docs MCP server; self-hosted variant; a separate Fern MCP server for builders |
| Who it's for | API companies publishing developer docs with Fern |
| Open source? | Not stated on the pages we checked |
| Pricing | Free $0 (250 AI credits/mo); Enterprise custom |
| Founded / HQ | "Born in Brooklyn, New York," per its footer |
What Fern offers for MCP
The hosted docs MCP server
Fern's MCP docs say it "automatically generates and hosts a production-ready" MCP server for every docs site with Ask Fern enabled. The server lives at your-documentation-site.com/_mcp/server. Fern's own is at https://buildwithfern.com/learn/_mcp/server.
The server exposes "a single tool" that answers questions using the same retrieval augmented generation (RAG) pipeline as Ask Fern. In plain terms, it searches your indexed pages and writes an answer, rather than returning a list of links.
Connecting clients
Fern adds two one-click buttons to docs pages. "Connect to Claude Code" copies a claude mcp add command. "Connect to Cursor" opens Cursor with the server URL filled in. Other clients, such as Claude Desktop, Windsurf (now Devin Desktop) and VS Code, use the URL directly. The docs show this command for CLI clients:
claude mcp add --transport http \
fern_mcp_docs.example.com https://docs.example.com/_mcp/serverSelf-hosted containers
Self-hosted Fern containers also serve /_mcp/server, but without Ask Fern or AI credits. Instead, they expose two tools: searchDocs, a keyword search, and fetchPage, which returns a page's Markdown. Both apply the same access rules as a browser request.
A server for builders
The docs also point to a separate Fern MCP server for your own agent while you build your site. It covers Fern's product docs and your organization's Fern data. For how docs servers fit with discovery, see our guide to MCP server discovery.
Who it's for
The hosted server suits API companies that already publish docs on Fern and want developers' AI coding tools to answer from current docs. It is a reader-facing feature, not a way to expose your API's actions to agents.
Pricing
Fern's pricing page lists two docs plans as of October 2026:
| Plan | Price | Included |
|---|---|---|
| Free | $0, "free forever" | 10 team members, 1,000 pages, 250 AI credits a month, "Ask Fern, Fern Agent, and MCP server" |
| Enterprise | Custom | SSO, SCIM and advanced RBAC, custom AI credits, self-hosting, uptime SLA |
The page also has a separate pricing tab for Postman customers. Because each MCP message uses 2 credits, 250 free credits cover about 125 MCP messages a month, before any Ask Fern use on the site itself.
Security and trust
On sites with authentication, MCP clients must send a FERN_TOKEN header with a valid JWT. Without it, the server "only returns publicly visible content (if any)." You can turn the server off with mcp: false.
Fern's navigation describes its trust center as "SOC 2 compliant and secure." Ask for the report if you need the detail. Our MCP security hub covers broader checks.
Alternatives
- Mintlify hosts a search MCP server for every docs site, plus an admin server with write access.
- Speakeasy generates MCP servers that call your API, not just your docs.
- APIMatic builds MCP servers, SDKs and docs from one OpenAPI source.
Postman also runs its own MCP server, covered in our Postman MCP server profile. Browse more MCP company spotlights.
Next step
A docs MCP server only helps once developers know it exists. Our MCP marketing team can help get it listed and found.
Frequently asked questions
Where is my Fern docs MCP server?
Fern's docs say it lives at your-documentation-site.com/_mcp/server on sites with Ask Fern enabled.
Does the MCP server cost extra?
It is included on the free plan, but each message uses 2 AI credits. The free plan includes 250 credits a month.
Can agents call my API through Fern's docs server?
No. The hosted server answers questions about your documentation. To let agents take actions in your API, you need an MCP server built for your API.
Who owns Fern?
Fern's site footer reads "Fern, a Postman company" and "Birch Solutions, Inc., a Postman company."
