Best Postman Alternatives

Firecamp is an open-source API DevTool supporting REST, GraphQL, WebSocket, and Socket.IO protocols as a lightweight alternative to Postman. It provides IntelliSense, team collaboration with shared workspaces, and seamless import from OpenAPI, Insomnia, AsyncAPI, and HAR formats. Each protocol gets a dedicated testing playground with response metrics including time, size, and status codes.

Knock is flexible notification and customer engagement infrastructure built for developers and AI agents. Send messages across email, SMS, push, chat, and in-app channels from a single API. Features AI-native journey building with single-prompt workflows, advanced segmentation with dynamic attributes, in-app messaging with custom components, data unification across warehouse and CDP, and version control with rollbacks. Delivers hundreds of millions of messages monthly with 99.99% uptime.