A practical field guide from Automation Ace.
Short answer: the leading managed app auth platforms for custom code and AI agents are Composio, Nango, Pipedream Connect, Arcade, and Zapier MCP. Each stores and refreshes your users' OAuth tokens so your code and agents can act in apps like Gmail, Slack, HubSpot, and GitHub without handling secrets. Choose Nango or Pipedream Connect when you want an authenticated proxy to call any endpoint from your backend, Composio or Arcade when you want ready-made agent tools with per-user authorization, and Zapier MCP when you want your own AI assistant to use apps you have already connected in Zapier.
Details reflect public documentation at the time of writing. Coverage, features, and pricing change quickly, so confirm with each vendor.
Short answer
- Composio: agent tool catalog with per-user connected accounts.
- Nango: auth, proxy, functions, and agent sessions; open source with self-hosting options.
- Pipedream Connect: managed auth, an API proxy, prebuilt actions, and MCP for your users.
- Arcade: agent tool calling built around per-user authorization.
- Zapier MCP: one MCP server that uses your existing Zapier app connections.
What managed app auth does
Calling a third-party API on behalf of a user normally means registering an OAuth app, building the consent flow, storing access and refresh tokens securely, refreshing them before they expire, handling revoked access, and doing it again for every provider. Managed app auth platforms do that for you and give you a connection (or connected account) ID instead of a token. Your code then calls the app through the platform's proxy, SDK, or tools, and the platform adds the credentials.
For the underlying concepts, see API authentication for automation and API credential terms explained.
Side-by-side comparison
| Composio | Nango | Pipedream Connect | Arcade | Zapier MCP | |
|---|---|---|---|---|---|
| Built for | AI agents that act in users' apps | Product integrations and agent tools | Embedding integrations and tools in your app | Agent tool calling with user authorization | Giving AI clients actions in your own apps |
| Main building blocks | Auth configs, connected accounts per user, tools | Integrations, connections, proxy, functions, agent sessions | Connect tokens, connected accounts, API proxy, actions, MCP | Tools, per-user authorization, MCP gateways | One MCP server with actions you enable |
| Call any endpoint (proxy) | Tools first; direct calls depend on SDK features | Yes, proxy with Connection-Id | Yes, Connect API proxy | Direct API calls with a user token, or tools | No; actions only (plus app API request actions) |
| MCP for agents | Yes | Yes (agent sessions) | Yes (remote MCP) | Yes (MCP gateways) | Yes, it is an MCP server |
| Multi-user (your end users) | Yes, by user ID | Yes, by connection and tags | Yes, by external user ID | Yes, by user ID | Built for your own and your team's accounts |
| Managed OAuth apps | Yes, plus custom auth configs | Yes for many APIs, plus your own | Yes, plus your own OAuth client | Defaults for some providers, plus custom providers | Zapier's app connections |
| Open source | SDKs | Yes, with self-hosting options | Many components | Tool SDKs and examples | No |
| Best fit | Agent builders who want a large tool catalog fast | Teams that want control, a proxy, and self-hosting options | Apps that need many APIs plus a proxy and prebuilt actions | Agents where per-user authorization of tools is central | Internal assistants using apps already in Zapier |
Composio
Composio is built around AI agents. You define auth configs per toolkit (the auth scheme, scopes, and whether Composio's managed OAuth app or your own is used), and each user who authorizes gets a connected account linked to your user ID. When you load tools for a user ID, they are scoped to that user's connected accounts. You can restrict which tools an agent or MCP server exposes, and use your own OAuth app through custom auth configs. Best for teams that want many agent-ready tools quickly.
Nango
Nango handles OAuth and API-key auth for hundreds of APIs, with Nango-managed OAuth apps for many providers (which Nango says can be used in production) or your own. Your backend creates short-lived connect sessions tagged with your user and organization IDs, users authorize through Nango's Connect UI, and you store the resulting connection ID. You can then call any endpoint through the proxy (Nango adds the Authorization header and can retry), run functions, or create agent sessions that give an agent an MCP URL with an allow or deny list of tools. Nango is open source, with self-hosting options.
Pipedream Connect
Pipedream Connect lets your users connect their accounts inside your app using a short-lived connect token your server creates. Each connection belongs to your external user ID. You can then call any API through the Connect API proxy, run Pipedream's prebuilt actions and triggers, or give agents tools through Pipedream's remote MCP server. You can use Pipedream's OAuth clients or your own. Best when you want broad app coverage plus both raw API access and prebuilt actions.
Arcade
Arcade focuses on agent tool calling with user authorization. Your agent runs tools for a user ID; when a tool needs access the user has not granted, Arcade returns an authorization URL, the user approves, and Arcade stores the tokens for later calls. Custom tools can declare the OAuth provider and scopes they need, and MCP gateways let you choose which tools each gateway exposes. Best for agent products where per-user, per-tool authorization is the core requirement.
Zapier MCP
Zapier MCP is a hosted MCP server that gives an AI client actions across thousands of apps, using the app connections already in your Zapier account. You choose which actions are enabled and can fix field values, and calls appear in Zapier's history. It is ideal for your own or your team's assistants, not for connecting your product's end users. See what Zapier MCP is and Zapier MCP security and task usage.
Which one fits
| If you need… | Look first at |
|---|---|
| Your own AI assistant to use your Zapier-connected apps today | Zapier MCP |
| A large catalog of ready-made agent tools for your users | Composio or Pipedream Connect |
| Raw API access with refresh handled, from your backend | Nango proxy or the Pipedream Connect API proxy |
| Fine-grained per-session tool policies for agents | Nango agent sessions, Composio tool restrictions, or Arcade gateways |
| Per-user authorization prompts inside the agent flow | Arcade or Composio |
| Self-hosting or open-source control | Nango |
| Fixed, high-volume workflows rather than agents | Zapier, Make, or n8n workflows |
Evaluation checklist
| Criterion | What to check |
|---|---|
| API coverage | Your must-have apps, the auth types they use, and how actively they are maintained |
| Proxy vs tools | Can you call any endpoint, or only predefined actions? |
| Token exposure | Can you fetch raw tokens? Can you avoid it? Who can? |
| Multi-tenant model | How users, organizations, and multiple accounts per app are represented |
| OAuth app ownership | Managed apps, your own clients, custom callback domains, and migration between them |
| Agent controls | Tool allowlists, per-session scoping, approvals, and logs |
| Reconnect UX | How expired or revoked connections are detected and fixed |
| Observability | Request logs, tool-call logs, webhooks for auth events |
| Security and compliance | Encryption, SOC 2 or similar reports, data residency, self-hosting |
| Pricing model | Per connection, per call, per user, or plan-based; how agents change the math |
Where to go next
- Code without tokens: calling third-party APIs from JavaScript without managing OAuth tokens.
- Edge runtimes: managed app auth in a Cloudflare Worker.
- Architecture: direct API calls vs authenticated proxies vs MCP tool calls.
- Agents: agents without token access, multi-user connections, and limiting app actions.
- OAuth ownership: managed OAuth app vs your own OAuth client.
Frequently asked questions
What is managed app auth?
Managed app auth is a service that handles OAuth and API-key connections to third-party apps for you: the consent flow, secure token storage, refresh, and revocation. Your code and AI agents use a connection ID, proxy, or tools instead of handling tokens directly.
What are the best managed app auth platforms for AI agents?
Common choices are Composio, Nango, Pipedream Connect, Arcade, and Zapier MCP. Composio and Arcade focus on agent tools with per-user authorization, Nango and Pipedream Connect add authenticated proxies for any endpoint, and Zapier MCP gives your own AI client actions using your Zapier connections.
Which managed auth platform lets me call any API endpoint?
Nango’s proxy and the Pipedream Connect API proxy let your backend call arbitrary endpoints for a connected account while the platform adds credentials. Tool-first platforms focus on predefined actions, though many also offer direct API options.
Is Zapier MCP a managed auth platform for my app’s users?
Not really. Zapier MCP uses the app connections in your own Zapier account and is best for your or your team’s AI assistants. To connect your product’s end users, use a platform built for multi-tenant connections such as Composio, Nango, Pipedream Connect, or Arcade.
How do I choose a managed app auth platform?
Check coverage of your must-have apps, whether you need a proxy or tools, whether raw tokens are exposed, the multi-tenant model, OAuth app ownership, agent controls, reconnect handling, logs, security and compliance, and pricing at your expected usage.
Disclaimer: Managed app auth platforms, their SDKs, endpoints, plans, and features change quickly; details reflect public documentation and coverage at the time of writing, so confirm current details with each provider before building. Automation Ace is not affiliated with Composio, Nango, Pipedream, Arcade, or the other companies named here unless a link is marked as an affiliate link. This article may include links to apps, products, or services; some links may be affiliate links, which means Automation Ace may earn a commission at no extra cost to you.