ACI.dev vs Nango: Which is Better in 2026?
Choosing between ACI.dev and Nango? Both are popular agent auth & tool calling tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.
Quick verdict
Both ACI.dev and Nango are strong agent auth & tool calling choices. The right pick comes down to your specific feature needs, existing stack, and team preferences. In our catalog, Nango rates slightly higher (4.5 vs 4.1 out of 5).
ACI.dev vs Nango — Side by Side
| ACI.dev | Nango | |
|---|---|---|
| Category | Agent Auth & Tool Calling | Agent Auth & Tool Calling |
| Pricing | Free · then usage-based | Free · paid from $50/mo |
| Starting price | Free tier available | Free tier available |
| Free tier | ||
| Rating | 4.1 | 4.5 |
| Best for | Agent Auth & Tool Calling — open-source, mcp | Agent Auth & Tool Calling — oauth, integrations |
Pros & Cons
- Apache-2.0: truly open source and self-hostable
- Multi-tenant OAuth for end users built in
- One MCP server for all tools
- No commits to the main repo since May 2026
- Smaller catalog than hosted rivals
- You run and secure the token store yourself
- 1,000+ APIs with managed OAuth
- Syncs and webhooks as well as tool calls
- Source on GitHub; free self-host for auth
- Elastic License 2.0, not OSI open source
- Free self-host excludes syncs, tool calls and MCP
- Per-connection pricing grows with users
Key Features Compared
ACI.dev
- 600+ integrations
- Multi-tenant OAuth
- Unified MCP server
- Self-hosted
Nango
- $0.29 per connection
- $0.72 per compute hour
- $0.50 per GB
Choose ACI.dev if…
- You want a free tier to validate before paying.
- Apache-2.0: truly open source and self-hostable
- Multi-tenant OAuth for end users built in
- One MCP server for all tools
Choose Nango if…
- You want a free tier to validate before paying.
- 1,000+ APIs with managed OAuth
- Syncs and webhooks as well as tool calls
- Source on GitHub; free self-host for auth
Frequently Asked Questions
Is ACI.dev better than Nango?⌄
Both ACI.dev and Nango are strong agent auth & tool calling choices. The right pick comes down to your specific feature needs, existing stack, and team preferences. In our catalog, Nango rates slightly higher (4.5 vs 4.1 out of 5).
What is the difference between ACI.dev and Nango?⌄
ACI.dev — Open-source (Apache-2.0) tool-calling platform: 600+ integrations, multi-tenant OAuth for end users, and a unified MCP server. Nango — Source-available integration platform: managed OAuth for 1,000+ APIs, tool calls and an MCP server, syncs and webhooks. Free self-host for auth and proxy. Both are agent auth & tool calling tools; the comparison table above breaks down pricing, free tiers, and what each is best for.
ACI.dev vs Nango: which is cheaper?⌄
ACI.dev pricing: Free · then usage-based. Nango pricing: Free · paid from $50/mo. Confirm current pricing on each tool's official site, as plans change.
Which is rated higher, ACI.dev or Nango?⌄
In our catalog, ACI.dev rates 4.1 out of 5 and Nango rates 4.5 out of 5, so Nango has a slight edge on reviews.
See more options in our guide to the best agent auth & tool calling tools for startups.
In-depth guideComposio vs Arcade (2026): Agent Auth & Tool Calling, Plus Open-Source Nango and ACI.devYour agent has to act inside Gmail, Slack and Salesforce as each of your users, without the model seeing a token. Composio and Arcade compared with Nango and ACI.dev on OAuth handling, licence and cost at 50 and 1,000 users.Still not sure which to pick?
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