# Skill authentication

Keep Skill credentials in XMEMO_KEY or the supported device-login flow, never in public output.

- Canonical: https://docs.xmemo.dev/docs/skills/authentication
- Locale: en-US
- Content-Locale: en-US
- Canonical-Content-Digest: 05a6eee6b593869aa4665f848843dd59f6a8b9040a9a95f11509939e6d731f5d
- Edition-Digest: 37a83f7ff9a5747c008f044a48834137d4fd9f539acf16d2ef1775b295cc8a63
- Source-Revision: sha256:7b1a43ae211b8ec0ac153c311e52f28ea045a0d1d8b84cd6098424ee4f89d29c

## Two credential paths

The Skill authenticates with XMEMO_KEY from the environment, or through the supported device-login flow. Credentials never belong in Skill output or in a file the agent can echo back.

- XMEMO_KEY in the environment or a supported secret store.
- Device login for interactive setup without pasting a token.
- Never print the token value in agent output.

## Environment credential

```bash
export XMEMO_KEY='<your-xmemo-token>'
```

## Sign in without pasting tokens

The first run can start device-code login. The user approves in the browser, and the browser page never displays the bearer token. The Skill stores a user-scoped credential file, and logout self-revokes the active token.

```bash
node skills/xmemo/scripts/xmemo-skill.mjs login
node skills/xmemo/scripts/xmemo-skill.mjs auth-status --verify
node skills/xmemo/scripts/xmemo-skill.mjs logout
```

## Device login endpoints

These are the four endpoints the login and logout commands call. A client never needs to call them directly, but they are what the flow is built from.

```http
POST /v1/auth/device/start           # initiate device authorization code flow
POST /v1/auth/device/token           # exchange device code for a session token
POST /v1/auth/token/validate         # validate current token authenticity
POST /v1/auth/token/revoke-self      # revoke current token and sign out
```

## Credential handling rules

- No token exposure: discovery responses and local runtime execution never print active tokens.
- No commits: cached credentials must be kept out of version control and public repositories.
- Fail-closed: bad credentials fail the doctor check instead of silently allowing anonymous operations.
- Separate surfaces: MCP configuration is optional and isolated from the standalone Skill runtime.