> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vendo.run/llms.txt
> Use this file to discover all available pages before exploring further.

# E-MCP-007

> The local MCP registry auth challenge is malformed.

# E-MCP-007

<Warning>
  **what doctor prints** (broken)

  local MCP registry auth challenge must start with v=MCPv1
</Warning>

The file that proves you own this domain to an MCP registry exists on disk,
but its contents are not a valid challenge.

`check mcp/registry-auth-local` · `error_code E-MCP-007` · `doctor exits 1`

## What you're seeing

Doctor only runs this check when
`public/.well-known/mcp-registry-auth` exists in the repo. It reads the file
and checks that the content starts with the literal string `v=MCPv1`.

## Why

An MCP registry verifies domain ownership by asking for a signed challenge
string served at a well-known path. The file's first bytes must name the
protocol version it speaks; anything else is not a challenge a registry can
verify, whatever else the file contains.

## The fix

Regenerate the domain-verification material rather than hand-editing it:

```bash theme={null}
npx vendo mcp verify-domain --domain your-app.example.com \
  --key-out ./mcp-registry.key \
  --write-well-known public
```

Re-run doctor once the file starts with `v=MCPv1`.

## Related errors

<CardGroup cols={2}>
  <Card title="E-MCP-008" href="/production/troubleshooting/e-mcp-008">live auth challenge malformed</Card>
  <Card title="E-MCP-004" href="/production/troubleshooting/e-mcp-004">server.json validation</Card>
</CardGroup>