fix: correct MCP registry remote URL in server.json (#26755)

mirror of https://github.com/coder/coder.git synced 2026-09-24 15:04:27 +08:00

The MCP Registry rejects our `server.json` remote because the URL uses
`{coder_url}` as the entire base. Registry validation requires remote
URLs to literally begin with `https://`, and template variables are only
allowed after the scheme/host. The previous value
(`{coder_url}/api/experimental/mcp/http`) fails both the JSON schema
`^https?://[^\s]+$` pattern and the semantic remote-URL check.

## Changes

- Use `https://{coder_hostname}/api/experimental/mcp/http` with a
`coder_hostname` variable (users now enter a hostname like
`coder.example.com` instead of a full URL).
- Update the VS Code registry instructions in
`docs/ai-coder/mcp-server.md` to ask for the deployment hostname.

Verified with `mcp-publisher validate` against
`registry.modelcontextprotocol.io`:

```
Validating against https://registry.modelcontextprotocol.io...
✅ server.json is valid
```

This was caught by running the `Publish to MCP Registry` workflow in
validate-only mode (`publish: false`) before any real publish, so
nothing broken reached the public registry.

<details>
<summary>Root cause detail</summary>

The registry validator (`internal/validators`) substitutes known
template variables, then parses the URL. Because `{coder_url}` replaces
the whole scheme+host, the parsed URL has no scheme and is rejected as
an invalid remote URL. Hard-coding `https://` and scoping the variable
to the host satisfies both the schema pattern and `IsValidRemoteURL`
(which also requires `https`). The registry mandates `https` for remotes
regardless, so there is no loss of functionality.

</details>

---
_Generated with Coder Agents._

This commit is contained in:

Ben Potter

2026-06-26 16:32:32 +00:00

committed by

GitHub

parent 6189d6e386

commit 73cd34cc5f

2 changed files with 5 additions and 5 deletions

									
										docs/ai-coder/mcp-server.md
									
		+1
		-1
	
												View File
												
				@@ -112,7 +112,7 @@ as `io.github.coder/coder`, enabling easy installation in supported MCP clients.

				1. Open VS Code Command Palette and run **MCP: Add Server...**

				1. Select **From MCP Registry**

				1. Search for "Coder" and select it

				1. Enter your Coder deployment URL when prompted (e.g., `https://coder.example.com`)

				1. Enter your Coder deployment hostname when prompted (e.g., `coder.example.com`)

				1. VS Code will automatically handle OAuth2 authentication

				#### Claude Desktop (Remote)