diff --git a/solana/bridge/program/src/instructions.rs b/solana/bridge/program/src/instructions.rs
new file mode 100644
index 000000000..fc548c928
--- /dev/null
+++ b/solana/bridge/program/src/instructions.rs
@@ -0,0 +1,212 @@
+use borsh::BorshSerialize;
+use solitaire::processors::seeded::Seeded;
+use solitaire::AccountState;
+use solana_program::{
+    borsh::try_from_slice_unchecked,
+    hash,
+    instruction::{
+        AccountMeta,
+        Instruction,
+    },
+    program_pack::Pack,
+    pubkey::Pubkey,
+    system_instruction::{
+        self,
+        create_account,
+    },
+    system_program,
+    sysvar,
+};
+
+use crate::{
+    accounts::{
+        Bridge,
+        FeeCollector,
+        GuardianSet,
+        GuardianSetDerivationData,
+        Message,
+        MessageDerivationData,
+        Sequence,
+        SequenceDerivationData,
+        SignatureSet,
+        SignaturesSetDerivationData,
+    },
+    types::PostedMessage,
+    BridgeConfig,
+    PostMessageData,
+    PostVAAData,
+    VerifySignaturesData,
+};
+
+pub fn initialize(
+    program_id: Pubkey,
+    payer: Pubkey,
+    bridge: Pubkey,
+    guardian_set_index: u32,
+    guardian_set: Pubkey,
+    fee: u64,
+    guardian_set_expiration_time: u32,
+) -> solitaire::Result<Instruction> {
+    let bridge = Bridge::<'_, { AccountState::Uninitialized }>::key(None, &program_id);
+    let guardian_set = GuardianSet::<'_, { AccountState::Uninitialized }>::key(
+        &GuardianSetDerivationData {
+            index: guardian_set_index,
+        },
+        &program_id,
+    );
+
+    Ok(Instruction {
+        program_id,
+        accounts: vec![
+            AccountMeta::new(bridge, false),
+            AccountMeta::new(guardian_set, false),
+            AccountMeta::new(payer, true),
+            AccountMeta::new_readonly(sysvar::rent::id(), false),
+            AccountMeta::new_readonly(solana_program::system_program::id(), false),
+        ],
+        data: crate::instruction::Instruction::Initialize(BridgeConfig {
+            fee,
+            guardian_set_expiration_time,
+        })
+        .try_to_vec()?,
+    })
+}
+
+pub fn post_message(
+    program_id: Pubkey,
+    payer: Pubkey,
+    bridge: Pubkey,
+    emitter: Pubkey,
+    message: PostedMessage,
+    sequence: u64,
+) -> solitaire::Result<Instruction> {
+    let bridge = Bridge::<'_, { AccountState::Uninitialized }>::key(None, &program_id);
+    let fee_collector = FeeCollector::<'_>::key(None, &program_id);
+    let sequence = Sequence::<'_>::key(&SequenceDerivationData {
+        emitter_key: &emitter,
+    }, &program_id);
+    let message = Message::<'_, { AccountState::Uninitialized }>::key(&MessageDerivationData {
+        emitter_key: emitter.to_bytes(),
+        emitter_chain: message.emitter_chain,
+        nonce: message.nonce,
+        payload: message.payload.clone(),
+    }, &program_id);
+
+    Ok(Instruction {
+        program_id,
+
+        accounts: vec![
+            AccountMeta::new(bridge, false),
+            AccountMeta::new(message, false),
+            AccountMeta::new(emitter, true),
+            AccountMeta::new(sequence, false),
+            AccountMeta::new(payer, true),
+            AccountMeta::new(fee_collector, false),
+            AccountMeta::new_readonly(sysvar::clock::id(), false),
+            AccountMeta::new_readonly(sysvar::rent::id(), false),
+            AccountMeta::new_readonly(solana_program::system_program::id(), false),
+        ],
+
+        data: crate::instruction::Instruction::PostMessage(PostMessageData {
+            nonce: 0,
+            payload: vec![],
+        })
+        .try_to_vec()?
+    })
+}
+
+pub fn verify_signatures(
+    program_id: Pubkey,
+    payer: Pubkey,
+    guardian_set_index: u32,
+    hash: [u8; 32],
+) -> solitaire::Result<Instruction> {
+    let guardian_set = GuardianSet::<'_, { AccountState::Uninitialized }>::key(
+        &GuardianSetDerivationData {
+            index: guardian_set_index,
+        },
+        &program_id,
+    );
+
+    let signature_set = SignatureSet::<'_, { AccountState::Uninitialized }>::key(
+        &SignaturesSetDerivationData { hash },
+        &program_id,
+    );
+
+    // Bridge with a single pre-existing signer.
+    // TODO: Get rid of this, exists to make testing easier for now.
+    let mut signers = [-1; 19];
+    signers[0] = 0;
+
+    Ok(Instruction {
+        program_id,
+
+        accounts: vec![
+            AccountMeta::new(payer, true),
+            AccountMeta::new(guardian_set, false),
+            AccountMeta::new(signature_set, false),
+            AccountMeta::new_readonly(sysvar::instructions::id(), false),
+            AccountMeta::new_readonly(sysvar::rent::id(), false),
+            AccountMeta::new_readonly(solana_program::system_program::id(), false),
+        ],
+
+        data: crate::instruction::Instruction::VerifySignatures(VerifySignaturesData {
+            hash,
+            signers,
+            initial_creation: true,
+        })
+        .try_to_vec()?
+    })
+}
+
+pub fn post_vaa(
+    program_id: Pubkey,
+    payer: Pubkey,
+    hash: [u8; 32],
+    message: Vec<u8>,
+    emitter: Pubkey,
+    guardian_set_index: u32,
+    vaa: PostVAAData,
+) -> Instruction {
+    let bridge = Bridge::<'_, { AccountState::Uninitialized }>::key(None, &program_id);
+    let guardian_set = GuardianSet::<'_, { AccountState::Uninitialized }>::key(
+        &GuardianSetDerivationData {
+            index: guardian_set_index,
+        },
+        &program_id,
+    );
+
+    let signature_set = SignatureSet::<'_, { AccountState::Uninitialized }>::key(
+        &SignaturesSetDerivationData { hash },
+        &program_id,
+    );
+
+    let message = Message::<'_, { AccountState::MaybeInitialized }>::key(
+        &MessageDerivationData {
+            emitter_key: emitter.to_bytes(),
+            emitter_chain: 1,
+            nonce: 0,
+            payload: message,
+        },
+        &program_id,
+    );
+
+    Instruction {
+        program_id,
+
+        accounts: vec![
+            AccountMeta::new(guardian_set, false),
+            AccountMeta::new(bridge, false),
+            AccountMeta::new(signature_set, false),
+            AccountMeta::new(message, false),
+            AccountMeta::new(payer, true),
+            AccountMeta::new_readonly(sysvar::clock::id(), false),
+            AccountMeta::new_readonly(sysvar::rent::id(), false),
+            AccountMeta::new_readonly(solana_program::system_program::id(), false),
+        ],
+
+        data: crate::instruction::Instruction::PostVAA(vaa)
+        .try_to_vec()
+        .unwrap(),
+    }
+}