quasar

Cross-Program Invocation — Quasar

This example contains two separate Quasar programs that work together:

• lever/ — A program with onchain PowerStatus state and a switch_power instruction that toggles a boolean.
• hand/ — A program that calls the lever program's switch_power via CPI.

Building

Each program is a separate Quasar workspace. Build them independently:

cd lever && quasar build
cd hand && quasar build

The hand program must be built after the lever, since its tests load the lever's compiled .so file.

Testing

cd lever && cargo test
cd hand && cargo test

The hand tests load both programs into QuasarSvm and verify that the CPI correctly toggles the lever's power state.

CPI Pattern

Quasar doesn't have a declare_program! equivalent for importing arbitrary program instruction types (unlike Anchor). Instead, the hand program:

1. Defines a marker type (LeverProgram) that implements the Id trait with the lever's program address
2. Uses Program<LeverProgram> in the accounts struct for compile-time address + executable validation
3. Builds the CPI instruction data manually using BufCpiCall, constructing the lever's wire format directly

This is lower-level than Anchor's CPI pattern but gives full control and works with any program.