Composio
Composio solves a specific, real developer problem — letting an AI agent actually call Gmail, GitHub, Slack, and a thousand-plus other tools with proper auth handling — rather than building that plumbing per project. It's usage-priced per tool call past the free tier, and it's a funded, San Francisco-based company (Series A led by Lightspeed) rather than a thin indie site.
Pros
- Over 1,000 pre-built integrations with handled authentication, rather than building each one manually
- Free tier includes 100,000 tool calls and unlimited connections a month before any charge
- Works with MCP clients (Claude Code, Cursor) as well as direct SDK integration
- Backed by a real Series A ($25M, led by Lightspeed) rather than an unfunded side project
Cons
- Pay-as-you-go overage pricing per tool call can get harder to predict at high volume
- Premium tools like browser automation cost meaningfully more than standard tool calls (roughly $0.70/task)