n8n-credentials-and-security

n8n Credentials and Security

Non-negotiables

1. Secrets via the credential system, never in text fields or SDK code. API keys, bearer tokens, OAuth secrets, passwords: all go through newCredential() or the node's credentials parameter. A Set node hardcoding a token and read via {{$json.token}} is a text field with extra steps.
2. Don't ask the user for credential names, but DO tell them to verify each node. The string in newCredential('Label') is cosmetic and does NOT bind to a specific stored credential. When the workflow opens, n8n auto-assigns the most recently edited credential of that type to every node, which silently picks the wrong one if the user has more than one (e.g., two Gmail accounts, prod + staging API keys). After building, always tell the user: "Open every node that uses a credential and confirm the right one is selected from the dropdown." Pick a sensible label ('Gmail', 'OpenRouter', 'Acme API') and move on.
3. Credential creation is the user's job, not yours. The n8n MCP doesn't expose credential creation. Tell the user the exact credential type to create in the UI, then reference it by label in your node config. Don't attempt to create credentials programmatically and don't accept secrets in chat to "set up later".

Strong defaults

• Use native credentials when available. Every native node (Slack, Gmail, Postgres, OpenAI, etc.) has a credential type. Don't reach for generic credential types when a native option exists.
• For multi-header or header-plus-query auth shapes, use the httpCustomAuth credential type. See references/CUSTOM_CREDENTIALS.md.

The credential system

In n8n, credentials are first-class objects:

• Stored encrypted at rest in the n8n database.
• Referenced by ID from nodes that need them.
• Scoped to projects (Cloud & enterprise) or shared globally (some self-hosted setups).
• Identified by a type slug (googleSheetsOAuth2Api, slackApi, httpHeaderAuth). The slug is what nodes reference and what determines which auth fields the credential collects.

A node that needs auth has a credentials parameter pointing to a credential ID + type. Secret values never appear in workflow JSON. Exporting a workflow leaks the reference, not the secret.

For the full model (SDK resolution, rotation, project scoping), see references/CREDENTIAL_SYSTEM.md.

Decision tree: how to authenticate this thing

Need to call an external service?
├── Native credential exists (Slack, Gmail, OpenAI, Postgres, ...)?
│   └── Use the native node + its credential type. Done.
│
├── Service is "standard-shaped" (REST + Bearer/Basic/OAuth)?
│   ├── Configure HTTP Request with one of the built-in auth types:
│   │   - Generic OAuth2
│   │   - Header Auth
|   |   - Bearer Auth (same as header auth but with only field being for actual token)
│   │   - Basic Auth
│   │   - Custom Auth
│   └── See references/HTTP_REQUEST_WITH_AUTH.md
│
└── Service needs multiple static headers, or headers plus query params?
    └── Use the httpCustomAuth credential type.
        See references/CUSTOM_CREDENTIALS.md

When the user pastes a secret into a chat

This happens. The user types something like:

"Set up a workflow to call Acme API with bearer sk-abc123def456"

What to do:

1. Don't put the token in a text field, even temporarily. A Set node that hardcodes the value and is referenced via {{$json.token}} is a text field with extra steps.
2. You place the node, the user creates the credential from it. You can't create credentials, the n8n MCP doesn't expose that. Tell the user: "I'll add the node configured for the right credential type (e.g. Bearer Auth for bearer tokens, Header Auth for other custom auth headers). When you open it, click the credential dropdown and choose 'Create new credential', and n8n will prompt you for the token there." The credential field on the node will either be empty (no credential of that type exists yet) or auto-filled with the user's most recently edited one of that type (see non-negotiable #2).
3. For programmatic credential creation, the MCP surface may be limited. See n8n-extending-mcp for wrapping n8n's credential APIs. The user must provide the secret value, and you should not be the persistent home for it.
4. Treat the pasted secret as compromised, and tell the user to rotate it. Don't soften this. The token has been transmitted to the LLM provider, may persist in chat history, transcripts, and cache layers, and is now outside the user's control. Tell them: "Rotate this token as soon as the new credential is set up in n8n. Pasting a secret into chat exposes it beyond this conversation. Treat it as leaked, not just visible."

When no native node exists

Common case: the user wants a service n8n has no node for. Use HTTP Request with appropriate auth.

• references/FINDING_API_DOCS.md: discovering auth scheme, base URL, common shapes.
• references/HTTP_REQUEST_WITH_AUTH.md: wiring HTTP Request to a credential.
• references/CUSTOM_CREDENTIALS.md: when built-in auth types don't fit.

Reference files

File	Read when
references/CREDENTIAL_SYSTEM.md	You need to understand how credentials are stored, referenced, scoped, or rotated
references/CUSTOM_CREDENTIALS.md	Multi-header / header-plus-query auth in one credential, or per-request signing patterns (HMAC, JWT, webhook validation)
references/HTTP_REQUEST_WITH_AUTH.md	Configuring HTTP Request with auth: Bearer, Basic, OAuth, Header Auth
references/FINDING_API_DOCS.md	The user mentioned a service you don't have node-level knowledge of

Anti-patterns

Anti-pattern	What goes wrong	Fix
Pasting sk-... into HTTP Request's Authorization header value field	Token in plain text in the workflow JSON, leaks on export, copy, screenshot	Use a credential: Bearer Auth for bearer tokens, Header Auth for other custom auth schemes
Storing token in a Set node and referencing via expression	Same problem, value lives in workflow JSON	Same fix: credential, not a Set node
Storing a secret in $vars.X and reading it as the auth value	Not encrypted at rest, leaks in exports, no rotation	Use the right credential type (httpBearerAuth, httpHeaderAuth, httpCustomAuth, or the native one). For inbound webhook auth, use the trigger's authentication field, not an IF on $vars.token
Reaching for $env.X to read a secret during custom auth setup	Doesn't work, throws at runtime	Use a credential of the appropriate type
Using HTTP Request when a native node exists	Loses auto-refresh on OAuth, loses native error handling, more code	Use the native node
Hardcoding credentials in SDK code (new HttpRequest({ headers: { Authorization: 'Bearer xxx' } }))	Same leak surface	Use newCredential() in SDK code
Asking the user to create a credential without naming the credential type	User picks the wrong type, auth fails confusingly	Always specify: "create a credential of type <exact type name>"