Sim

Sim (formerly Sim Studio) is an open-source AI workspace for building, deploying, and managing AI agents and agentic workflows. Teams compose workflows on a visual canvas using blocks like Agent, Router, Function, Condition, Loop, Parallel, Evaluator, Guardrails, and Human-in-the-Loop, then trigger them via schedules, webhooks, RSS feeds, tables, or chat. It connects 1,000+ integrations (Slack, GitHub, Gmail, Notion, Salesforce, Jira, Linear, Supabase, Stripe, and many more) and runs on every major LLM provider, including OpenAI, Anthropic, Google, DeepSeek, xAI, Groq, and Cerebras. Beyond workflows, Sim includes knowledge bases with live sync, built-in tables, file handling, logging and alerting, a 'Mothership' conversational builder, and Sim Mailer inbox automation. MCP support is prominent and bidirectional: agents can call external MCP tools inside workflows, and finished workflows can be deployed as MCP servers (alongside API and chat deployments), making Sim both an MCP client and server. The platform is open source (github.com/simstudioai/sim, 29k+ GitHub stars, 100,000+ builders) with Docker/Kubernetes self-hosting. Cloud pricing: Free ($0, 1,000 monthly credits, 1 workspace, 5 GB storage), Pro ($25/user/month, 6,000 credits, 3 workspaces, 50 GB), Max ($100/user/month, 25,000 credits, unlimited workspaces, 500 GB, Slack Connect, KB Live Sync), and custom Enterprise with SSO, access control, SOC2 compliance, audit logs, and dedicated support. Annual billing saves 15%.