Composio competitors, compared.
The main Composio alternatives for AI-agent tool-calling and credential brokering are Nango, Arcade, Merge, and Open Connector. They differ most on what actually matters for a credential broker: whether you can self-host it, where your users' tokens live, and whether it is genuinely open source.
Who can you self-host — and who holds the keys?
Most of these brokers are hosted SaaS that keep your users' tokens in their own cloud. The open, self-hostable end of the field is the short list that lets credentials stay on your infrastructure.
| Tool | Open source? | Self-host? | Credentials live | Pricing |
|---|---|---|---|---|
| Open Connector | Open-source core (AGPL-3.0) + commercial EE | Yes — free, anyone, from source | Your infrastructure (always) | Free core; pay only for optional EE features |
| Composio | SDK open (MIT); platform proprietary | Paid Enterprise tier only | Composio's cloud (VPC on Enterprise) | Free tier + usage-based (per tool call) |
| Nango | Source-available (Elastic License v2) | Yes — free (limited); paid for full parity | Your infra (self-host) or Nango's cloud | Free self-host; cloud is usage-based |
| Arcade | SDK + MCP framework open; platform hosted | Cloud, VPC, or on-prem (paid tiers) | Arcade's cloud (or your VPC) | Tiered cloud + self-hosted options |
| Merge | Proprietary | Paid add-on only | Merge's cloud | Free tier + usage; enterprise-priced |
Our reading of each vendor's public documentation and pricing as of June 2026; details change — verify with the vendor before deciding. All names and trademarks belong to their respective owners; this is an independent comparison.
Each option in a sentence
Open Connectorthis is us
Open Connector is the open-source, self-hostable broker: its core — connector engine, API, and dashboard — is licensed under the OSI-approved GNU AGPL-3.0, so anyone can run the whole thing for free with credentials that never leave their infrastructure. It is drop-in compatible with the Composio SDK, so migrating is a one-line baseURL change.
Composio
Composio is the most established option: a hosted tool-calling platform with managed OAuth and 1,000+ toolkits. The SDK is open source (MIT), but the broker platform is proprietary and runs in Composio's cloud — self-hosting is reserved for the paid Enterprise tier.
Nango
Nango is the closest direct alternative on the self-hostable-credential-layer axis: managed OAuth, API keys, and token refresh for 800+ APIs, self-hostable via Docker. Its code is source-available under the Elastic License v2 — which restricts offering it as a managed service — rather than an OSI-approved license like AGPL.
Arcade
Arcade is an authenticated tool-calling platform focused on task-time authorization for human-in-the-loop agents, with a 250+ community connector library. Its SDK and MCP-server framework are open source, but the runtime, catalog, and managed auth are a hosted product (VPC/on-prem available on paid tiers).
Merge
Merge is a unified-API platform; its newer Agent Handler exposes pre-built tool calls to agents over MCP. It is a proprietary, hosted product (self-hosting and single-tenancy are paid add-ons) and is priced toward enterprise, which gets expensive at higher connection counts.
Pick by what you optimize for.
- Teams that must own their credentials; migrating off ComposioOpen Connector
- Hosted breadth — 1,000+ managed toolkitsComposio
- Code-first OAuth across 800+ APIsNango
- Task-time authorization, human-in-the-loopArcade
- Unified API across SaaS categories (HRIS, CRM…)Merge
If your security review won't allow user tokens in a vendor's cloud — or you just want a broker you can read, run, and own — that is the gap Open Connector fills, with a one-line migration path off the Composio SDK.
Composio competitors, answered
- Who are Composio's main competitors?
- The main Composio alternatives for AI-agent tool-calling and credential brokering are Nango (code-first OAuth for 800+ APIs, self-hostable), Arcade (authenticated tool-calling with task-time authorization), Merge (a unified API with an agent handler), and Open Connector (the open-source, self-hostable broker that is drop-in compatible with the Composio SDK).
- What is the best open-source Composio alternative?
- If you want a genuinely open-source, self-hostable broker, Open Connector is the closest match: its core is licensed under the OSI-approved GNU AGPL-3.0 and runs entirely on your own infrastructure for free. Nango is also self-hostable but ships under the Elastic License v2 (source-available, not OSI-approved); Composio and Merge keep their platforms proprietary.
- Which Composio alternative can I self-host?
- Open Connector and Nango can both be self-hosted by anyone — Open Connector's whole core is free under AGPL-3.0, and Nango is free to self-host with a limited feature set. Composio, Arcade, and Merge offer self-hosting only on paid Enterprise or VPC tiers and ship proprietary components.
- Is there a free Composio alternative?
- Yes. Open Connector's core is free and open source — you self-host it and pay only for your own infrastructure (optional enterprise add-ons need a commercial license). Nango has a free self-hosted tier and a limited free cloud tier; Composio and Merge offer limited free tiers on otherwise usage-based paid plans.
The open option in the field.
Open Connector is the Composio alternative you actually own — open source, self-hosted, with credentials that never leave your infrastructure. Join the managed-beta waitlist, or self-host from source today.