Executable examples
Seven lessons. One coherent path through Blue.
Start with one Counter, then add deterministic BEX, connected documents, historical catch-up, repeated embedding paths, delegated authority, and durable retry. Every lesson explains one main idea and opens that exact live Playground scenario.
Learning path
Build the mental model in layers.
The sequence is deliberate: each example keeps the concepts already learned and introduces one new boundary.
Counter Basics
Alice increments, Bob decrements, and one document records both authenticated operations as immutable revisions.
Learn timelines and operations → 02 · Deterministic executionBEX Rules & Processing Gas
Compare simple and conditional workflows, inspect their returned effects, and see the deterministic gas consumed.
Learn BEX and gas → 03 · EmbeddingOne Counter, Two Hosts
Attach one managed Counter to two independent Hosts, catch both up, then fan out one later child revision.
Learn child reuse and fan-out → 04 · Historical catch-upNBA Game: Host Catch-Up
Complete a Game independently, attach it to a waiting Host, and replay its retained revision history in order.
Learn state machines and catch-up → 05 · Collection embeddingFive Embeddings, Three Games
Attach Alpha twice, Beta twice, and Gamma once while retaining only three unique managed child sessions.
Learn occurrence identity → 06 · Delegated authorityAlice’s Agent: Authority by Mandate
An Agent begins powerless, receives one exact active Mandate, acts for Alice, and loses authority when it ends.
Learn mandates and revocation → 07 · Durable deliverySafe Retry: One Entry, One Effect
Reject invalid input atomically, process a valid entry once, and retry without duplicating state, events, or gas.
Learn admission and idempotency →How to learn
Read the claim. Run one step. Inspect the evidence.
Open Guide inside the Playground and advance one action at a time. Watch who acts, which Timeline Entry is accepted, which document changes, what event is emitted, and how the new revision connects to the previous one.