The review
What it does
Relay Canvas lets you build agents by connecting blocks on a canvas: triggers, model steps, tools and, crucially, approval gates where a human has to say yes before anything leaves the building. You can test a workflow against sample data, see every step's input and output, and set spending and rate limits per agent.
Why we like it
Approval gates are a first-class block rather than an afterthought, which nudges beginners toward safe designs. The step-by-step run viewer is the best debugging tool we've seen in a no-code builder. It's where we'd send a non-technical team building its first real agent.
Watch out for
- Complex branching logic gets visually messy; large canvases need discipline.
- Some integrations are read-only on the free tier.
- Version history exists but diffing two versions of a canvas is awkward.
