LDK

LDK (Lightning Development Kit) lets you embed Lightning protocol logic inside your app. You bring storage, networking, and chain monitoring.

Complete Step 1 // Required reading in the study plan above, then continue here.

Step 2 — Core idea: you bring the chassis

Mobile wallets and custom servers often cannot run a full LND/CLN sidecar. LDK is how Lightning becomes a library dependency.

Analogy: LND/CLN are assembled cars. LDK is an engine kit — powerful, but you still build the chassis, fuel system, and dashboard.

You must provide durable channel-state storage, peer networking, and a chain source. Persistence bugs lose funds — test crash recovery aggressively.

Done when: You can list the three responsibilities LDK does not own for you.

Step 3 — Architecture sketch (lab)

Draw App → LDK → persistence / net / chain. Write one crash-recovery test you would run. Optional: skim LDK sample node docs.

Done when: Lab evidence (sketch + recovery test + source) is complete.

Next lesson

Watchtowers — breach detection when wallets are offline.