Cheatsheet

A one-page index of the dspy4s surface. Each row links to the page that covers it in full. For runnable versions of every construct below, see Cheatsheet.scala in the examples module.

Declare a task

I want to	Use	Page
Declare inputs and outputs	Signature.fromType / Signature.fromString	Signatures
Use named fields, enums, custom types	Spec trait + Signature.of[T]	Signatures

Run a task

I want to	Use	Page
Answer directly	Predict	Modules
Reason first	ChainOfThought	Modules
Call tools in a loop	ReAct	Tools & ReAct
Sample and keep the best	BestOfN / Refine	Modules
Chain steps into one program	DynamicModule	Composing programs

Talk to a model

I want to	Use	Page
Configure a model	OpenAiLanguageModel	Configuring an LM
Pick text vs JSON output	ChatAdapter / JSONAdapter	Adapters
Cache or track usage	ManagedLanguageModel, UsageTracking	Caching & usage

Measure and improve

I want to	Use	Page
Build labeled data	Example, withInputs	Examples & data
Score outputs	FunctionMetric, SemanticF1	Metrics
Run a batch evaluation	Evaluate	Running evaluations
Improve demonstrations	BootstrapFewShot, KNNFewShot	Few-shot
Improve instructions	COPRO, MIPROv2, GEPA	Instructions

Operate

I want to	Use	Page
Configure the active model/adapter	RuntimeContext, RuntimeEnvironment	Runtime context
Observe a run	CallbackHandler, inspectHistory	Observability
Persist a tuned program	ProgramPersistence	Saving & loading
Stream output	Streamify, StreamListener	Streaming