native-rust-vrf-example

Native Solana program (no Anchor) that uses MagicBlock Ephemeral VRF via ephemeral-vrf-sdk: the user requests randomness; the VRF program callbacks with 32 bytes; you derive a value (e.g. 1–10) and store it in PlayerState.

Program id: ELajHfg4BFcoKrC7ARDKMmqoKQrZMbr88h3xAjy9PY4X (see src/lib.rs).

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Instructions (what each one does)

InitializePlayer (Borsh: wallet → your program)

• Caller: user (signs as authority).
• Effect: creates the player PDA for seeds ["player", authority], writes PlayerState (discriminator, random_value initially 0, bump).
• File: src/instructions/initialize_player.rs

RequestRandomness { client_seed: u8 } (Borsh: wallet → your program)

• Caller: user (payer signs).
• Effect: checks queue / accounts, builds RequestRandomnessParams and CPIs the ephemeral VRF program with create_request_randomness_ix. Your program signs the CPI using the identity PDA (["identity"] under this program). The request encodes which callback to run and which accounts the VRF will pass when it invokes you (e.g. the player PDA as writable). This instruction does not set the final roll; it only records the request on-chain and triggers the VRF.
• File: src/instructions/request_randomness.rs

VRF callback → CallbackConsumeRandomness (not plain Borsh on the same enum)

• Caller: the VRF program, not the user. Instruction data = fixed 8-byte prefix (see vrf_lite::CALLBACK_CONSUME_RANDOMNESS) + 32 random bytes (40 bytes total). src/processor.rs routes this before VrfInstruction::try_from_slice, because it is not the same layout as your wallet Borsh instructions.
• Effect: verifies VRF_PROGRAM_IDENTITY is the signer, parses the 32-byte seed, maps it (e.g. rnd::random_u8_with_range → 1–10), updates PlayerState.random_value on the player PDA.
• Files: src/vrf_lite.rs, src/instructions/callback_consume_randomness.rs

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Build and deploy

cargo build-sbf
solana program deploy target/deploy/<your_program>.so --program-id reflex_program-keypair.json

Upgrade the same program id when you change the .so (redeploy with the same program keypair).

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Client tests (test/)

cd test
npm install
# Off-chain Borsh checks only
npm test
# On-chain: devnet (or set SOLANA_RPC_URL / SOLANA_WS_URL); needs payer keypair
RUN_INTEGRATION=1 npm test

• RUN_INIT_INTEGRATION=1: also runs the initialize_player chain test (default off so you can focus on VRF if the player PDA already exists).
• AUTO_INIT_PLAYER=1: with RUN_INTEGRATION=1, creates the player PDA if missing before the VRF test.

PROGRAM_ID in the client matches getTestProgramId() in test/utils.ts (override with env).

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Security note

Do not commit reflex_program-keypair.json or .env; they are listed in .gitignore.