NudgeVariants
Define multiple prompt variants for A/B testing.
A/B Testing with Variants
Define multiple variants of a prompt for A/B testing. Each variant adds additional steps to the base prompt, giving you explicit control over what differs between variants.
prompt("summarizer", (p) =>
p
.persona("expert summarizer")
.input("text to summarize")
.output("concise summary")
// Define variants - each adds steps to the base prompt
.variant("short", (v) =>
v.constraint("keep the summary to 1-2 sentences maximum")
)
.variant("detailed", (v) =>
v
.do("explain the context and background")
.do("include specific examples where relevant")
)
);How it works
- Base prompt: persona + input + output
- Variant "short": base + constraint (1-2 sentences)
- Variant "detailed": base + do (context) + do (examples)
Each variant generates a separate prompt via the AI, ensuring meaningful differences.
Using variants at runtime
// Variant names are typed!
summarizerPrompt.toString({ variant: "short" });
summarizerPrompt.toString({ variant: "detailed" });
// List available variants
console.log(summarizerPrompt.variantNames); // ["short", "detailed"]A/B testing
const variants = summarizerPrompt.variantNames;
const randomVariant = variants[Math.floor(Math.random() * variants.length)];
summarizerPrompt.toString({ variant: randomVariant });Variant names are fully typed—TypeScript will autocomplete available options and error on invalid ones.