7 Free AI Tools Every Developer Should Bookmark (2026)

The AI tool landscape is noisy. Every week there is a new "game-changing" tool that costs $20/month and requires three API keys to set up. These 7 are different. They are free, they work right now, and they solve real problems I hit every day as a developer. No waitlists. No credit card required. Just tools that save time. 1. mcp-openapi -- Connect Claude to Any REST API in One Command If you work with APIs (and you do), this is the one tool that changed my workflow the most. Point mcp-openapi at any OpenAPI or Swagger spec URL, and it auto-generates MCP tools for every endpoint. Claude can then explore and call the API directly from your terminal. No code. No config files. No manual mapping. Install: npx -y mcp-openapi Example -- connect Claude to the Petstore API: { "mcpServers" : { "petstore" : { "command" : "npx" , "args" : [ "-y" , "mcp-openapi" ], "env" : { "API_BASE_URL" : "https://petstore3.swagger.io" , "OPENAPI_SPEC_URL" : "https://petstore3.swagger.io/api/v3/openapi.json" }