> **Building with AI coding agents?** If you're using an AI coding agent, install the official Scalekit plugin. It gives your agent full awareness of the Scalekit API — reducing hallucinations and enabling faster, more accurate code generation.
>
> - **Claude Code**: `/plugin marketplace add scalekit-inc/claude-code-authstack` then `/plugin install <auth-type>@scalekit-auth-stack`
> - **GitHub Copilot CLI**: `copilot plugin marketplace add scalekit-inc/github-copilot-authstack` then `copilot plugin install <auth-type>@scalekit-auth-stack`
> - **Codex**: run the bash installer, restart, then open Plugin Directory and enable `<auth-type>`
> - **Skills CLI** (Windsurf, Cline, 40+ agents): `npx skills add scalekit-inc/skills --list` then `--skill <skill-name>`
>
> `<auth-type>` / `<skill-name>`: `agentkit`, `full-stack-auth`, `mcp-auth`, `modular-sso`, `modular-scim` — [Full setup guide](https://docs.scalekit.com/dev-kit/build-with-ai/)

---

# Authentication Methods Comparison

Compare different authentication methods supported by AgentKit including OAuth 2.0, API Keys, Bearer Tokens, and Custom JWT to choose the right approach.
AgentKit supports multiple authentication methods to connect with third-party providers. This guide helps you understand the differences and choose the right authentication method for your use case.

## Authentication methods overview

**Most secure and widely supported**

User-delegated authentication with automatic token refresh and granular permissions.

**Best for:** Google, Microsoft, Slack, GitHub

**Simple static credentials**

Provider-issued keys for straightforward server-to-server authentication.

**Best for:** Jira, Asana, Linear, Airtable

**User-generated tokens**

Personal access tokens with scoped permissions for individual use.

**Best for:** GitHub PATs, GitLab tokens

**Advanced signed tokens**

Cryptographically signed tokens for service accounts and custom protocols.

**Best for:** Custom integrations, service accounts

## Comparison matrix

| Feature | OAuth 2.0 | API Keys | Bearer Tokens | Custom JWT |
|---------|-----------|----------|---------------|------------|
| **Security Level** | High | Medium | Medium | High |
| **User Interaction** | Required | Optional | Required | Not required |
| **Token Refresh** | Automatic | N/A | Manual | Varies |
| **Setup Complexity** | Moderate | Easy | Easy | Complex |
| **Granular Permissions** | Yes | Limited | Yes | Limited |
| **Provider Support** | Widespread | Common | Common | Limited |

## When to use each method

### OAuth 2.0

**Use when:**
- Provider supports OAuth
- Acting on behalf of users
- Need automatic token refresh
- Require granular permissions
- Building user-facing applications

**Example:** User connects Gmail to send emails through your app

### API Keys

**Use when:**
- Provider only supports API keys
- Building internal tools
- Server-to-server communication
- Simplicity is priority

**Example:** Automated Jira ticket creation for support system

### Bearer Tokens

**Use when:**
- Personal access is sufficient
- Building developer tools
- OAuth unavailable
- User prefers manual control

**Example:** Personal GitHub repository automation

### Custom JWT

**Use when:**
- Provider requires JWT
- Service account access needed
- Custom authentication protocol
- Advanced security requirements

**Example:** Enterprise service account integrations

## Next steps

- [Connectors](/agentkit/connectors) - Available third-party providers
- [Connections](/agentkit/connections) - Configure provider connections
- [Authorization Methods](/agentkit/tools/authorize) - Detailed authentication implementation


---

## More Scalekit documentation

| Resource | What it contains | When to use it |
|----------|-----------------|----------------|
| [/llms.txt](/llms.txt) | Structured index with routing hints per product area | Start here — find which documentation set covers your topic before loading full content |
| [/llms-full.txt](/llms-full.txt) | Complete documentation for all Scalekit products in one file | Use when you need exhaustive context across multiple products or when the topic spans several areas |
| [sitemap-0.xml](https://docs.scalekit.com/sitemap-0.xml) | Full URL list of every documentation page | Use to discover specific page URLs you can fetch for targeted, page-level answers |