OpenBook vs Stack AI
Stack AI is a closed-source enterprise SaaS for building AI agents and LLM workflows, with strong RAG, compliance, and deployment options for larger organizations. OpenBook offers a comparable visual agent builder, but open source and self-hostable: agents with long-term memory, an AI builder, and human-in-the-loop, with your data, prompts, and keys on your own infrastructure and no per-credit metering.
At a glance
OpenBook and Stack AI, capability by capability.
| Capability | OpenBook | Stack AI |
|---|---|---|
| Open source | ||
| Self-hostable | Enterprise deployment options | |
| Visual agent builder | ||
| AI builds the workflow for you | Partial | |
| Agents with long-term memory | Configurable | |
| Human-in-the-loop | ||
| Built-in RAG / knowledge base | Via actions/plugins | |
| Bring your own model keys | Limited | |
| No per-credit billing |
Why teams pick OpenBook over Stack AI
Open source & self-hosted
Run OpenBook on your infrastructure and audit every line. Stack AI is a closed SaaS, though it offers enterprise deployment options.
No per-credit metering
Pay your model provider directly with no per-run credit billing. Predictable at scale.
Own your data and prompts
Nothing leaves your infrastructure unless you send it — useful for regulated teams that still want source access.
AI builder + real workflow engine
Describe a workflow and OpenBook wires the agents and graph, with branching, error paths, and human-in-the-loop.
MIT, self-host, your keys.
Closed SaaS with enterprise plans and credit-based pricing.
When to choose which
- You want full source access and self-hosting, not just an enterprise deployment of a closed product
- You want to avoid per-credit metering and own your data and prompts
- You want an AI builder and a real workflow engine with human-in-the-loop
- You want a managed enterprise SaaS with mature RAG, SSO, and compliance out of the box
- You prefer vendor-supported deployment and a curated enterprise catalog
Recreate each Stack AI agent as an OpenBook agent (prompt + actions) and each workflow as a graph. Move knowledge bases into RAG actions or plugins; the AI builder can scaffold the graph.
Frequently asked questions
Build your first agentic workflow today.
OpenBook is free and open source. Self-host it in minutes, or read the docs to see how far the engine goes.