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MCPX_CONFIG_MISSING_SECRET

Severity: error Domain: Config

What happened​

The upstream config references a secret (typically via ${SECRET:NAME} in env or headers), but the secret was not found in the active secret store when mcpproxy tried to start that server.

How to fix​

List what's defined​

mcpproxy secret list

If the name you referenced isn't there, add it.

Add the missing secret​

mcpproxy secret set <NAME>           # prompts for the value, never echoed

Secrets are stored in the OS keychain on macOS / Windows and in an encrypted file on Linux.

Check the reference syntax​

{
  // env values support ${SECRET:NAME} expansion:
  "env": { "GITHUB_TOKEN": "${SECRET:github_personal_token}" },

  // headers do too:
  "headers": { "Authorization": "Bearer ${SECRET:my_api_key}" }
}

Plain string values are used as-is (no expansion).

Migration from inline secrets​

If you previously stored secrets inline and want to move them into the secret store:

mcpproxy secret set github_personal_token < /dev/stdin <<<"ghp_xxx"
# Then update the config to use ${SECRET:github_personal_token}