--- title: Syscall Reference description: Complete reference for all sBPF syscalls available to Solana programs, including compute unit costs for hashing, cryptography, CPI, logging, memory operations, and more. url: /docs/core/programs/syscall-reference type: reference prerequisites: - /docs/core/programs - /docs/core/programs/program-execution related: - /docs/core/fees/compute-budget - /docs/core/cpi/cpi-cost-model - /docs/core/constants-reference --- Programs interact with the runtime through syscalls covering logging, hashing, cryptography, CPI, sysvars, memory operations, and more. Each deducts compute units from the transaction's shared budget. ## Syscalls Programs interact with the runtime through syscalls registered in [`create_program_runtime_environment_v1()`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L282). Each syscall deducts compute units from the transaction's compute budget. ### Syscall costs Each syscall's base compute unit cost constants are defined in [`SVMTransactionExecutionCost`](https://github.com/anza-xyz/agave/blob/v3.1.8/program-runtime/src/execution_budget.rs#L198-L236). Some syscalls combine these constants into more complex formulas in their implementation (e.g., scaling with input size or adding `syscall_base_cost` overhead). See the individual syscall source links below for exact cost calculations. ### Available syscalls The complete set of syscalls available to sBPF programs, as registered in [`create_program_runtime_environment_v1()`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L282). Feature-gated syscalls are only available when the corresponding feature is active on the cluster. #### Control flow | Syscall | Description | Source | | ------------ | -------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | | `abort` | Halts the program immediately. Inserted by LLVM for untenable conditions; not intended for explicit use. | [`SyscallAbort`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L691) | | `sol_panic_` | Halts the program with a file name, line, and column number for diagnostics. | [`SyscallPanic`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L710) | #### Logging | Syscall | Description | Source | | ------------------------ | ------------------------------------------------------ | -------------------------------------------------------------------------------------------------------- | | `sol_log_` | Logs a UTF-8 string message to the program log. | [`SyscallLog`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/logging.rs#L5) | | `sol_log_64_` | Logs five `u64` values as hex to the program log. | [`SyscallLogU64`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/logging.rs#L37) | | `sol_log_pubkey` | Logs a `Pubkey` as a base58 string to the program log. | [`SyscallLogPubkey`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/logging.rs#L84) | | `sol_log_compute_units_` | Logs the remaining compute units to the program log. | [`SyscallLogBpfComputeUnits`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/logging.rs#L60) | | `sol_log_data` | Logs arbitrary byte slices as base64-encoded data. | [`SyscallLogData`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/logging.rs#L109) | #### PDA | Syscall | Description | Source | | ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------- | | `sol_create_program_address` | Derives a program address from seeds and a program ID. Returns 1 if the derived address is on the Ed25519 curve (invalid PDA). | [`SyscallCreateProgramAddress`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L798) | | `sol_try_find_program_address` | Finds a valid PDA by iterating bump seeds from 255 down to 1. Returns the address and bump. | [`SyscallTryFindProgramAddress`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L836) | #### Hashing | Syscall | Description | Source | | --------------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | | `sol_sha256` | Computes a SHA-256 hash over one or more byte slices. | [`SyscallHash`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1912) | | `sol_keccak256` | Computes a Keccak-256 hash over one or more byte slices. | [`SyscallHash`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1912) | | `sol_blake3` | Computes a Blake3 hash over one or more byte slices. Feature-gated. | [`SyscallHash`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1912) | | `sol_poseidon` | Computes a Poseidon hash over inputs. Feature-gated. | [`SyscallPoseidon`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1737) | #### Cryptography | Syscall | Description | Source | | --------------------------- | -------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ | | `sol_secp256k1_recover` | Recovers a secp256k1 public key from a signed message hash and recovery ID. | [`SyscallSecp256k1Recover`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L888) | | `sol_curve_validate_point` | Validates that a byte array is a valid point on Curve25519 (Edwards or Ristretto). Feature-gated. | [`SyscallCurvePointValidation`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L946) | | `sol_curve_group_op` | Performs Curve25519 group operations (add, subtract, multiply) on Edwards or Ristretto points. Feature-gated. | [`SyscallCurveGroupOps`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1009) | | `sol_curve_multiscalar_mul` | Performs multi-scalar multiplication on Curve25519 Edwards or Ristretto points. Feature-gated. | [`SyscallCurveMultiscalarMultiplication`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1237) | | `sol_alt_bn128_group_op` | Performs alt_bn128 (BN254) group operations: G1 addition, G1 multiplication, and pairing check. Feature-gated. | [`SyscallAltBn128`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1558) | | `sol_alt_bn128_compression` | Compresses and decompresses alt_bn128 G1 and G2 points. Feature-gated. | [`SyscallAltBn128Compression`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1823) | | `sol_big_mod_exp` | Computes big integer modular exponentiation (base^exp mod modulus). Feature-gated. | [`SyscallBigModExp`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1662) | #### CPI | Syscall | Description | Source | | ------------------------ | ------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- | | `sol_invoke_signed_rust` | Invokes a cross-program instruction from a Rust program. Serializes instruction, accounts, and signer seeds using the Rust ABI. | [`SyscallInvokeSignedRust`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/cpi.rs#L11) | | `sol_invoke_signed_c` | Invokes a cross-program instruction from a C program. Uses the C `SolInstruction` ABI for serialization. | [`SyscallInvokeSignedC`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/cpi.rs#L78) | #### Sysvars | Syscall | Description | Source | | ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------- | | `sol_get_clock_sysvar` | Writes the Clock sysvar to a program-provided buffer. | [`SyscallGetClockSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L44) | | `sol_get_epoch_schedule_sysvar` | Writes the EpochSchedule sysvar to a program-provided buffer. | [`SyscallGetEpochScheduleSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L66) | | `sol_get_rent_sysvar` | Writes the Rent sysvar to a program-provided buffer. | [`SyscallGetRentSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L135) | | `sol_get_epoch_rewards_sysvar` | Writes the EpochRewards sysvar to a program-provided buffer. | [`SyscallGetEpochRewardsSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L88) | | `sol_get_last_restart_slot` | Writes the LastRestartSlot sysvar to a program-provided buffer. Feature-gated. | [`SyscallGetLastRestartSlotSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L157) | | `sol_get_fees_sysvar` | Writes the deprecated Fees sysvar to a program-provided buffer. Feature-gated (deprecated). | [`SyscallGetFeesSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L110) | | `sol_get_sysvar` | Generic sysvar access: reads a byte slice from any cached sysvar by its pubkey, offset, and length (SIMD-0127). Feature-gated. | [`SyscallGetSysvar`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/sysvar.rs#L184) | #### Memory operations | Syscall | Description | Source | | -------------- | ------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------- | | `sol_memcpy_` | Copies `n` bytes from source to destination. Aborts if regions overlap in VM address space. | [`SyscallMemcpy`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/mem_ops.rs#L26) | | `sol_memmove_` | Copies `n` bytes from source to destination, handling overlapping regions correctly. | [`SyscallMemmove`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/mem_ops.rs#L49) | | `sol_memcmp_` | Compares `n` bytes of two memory regions. Writes the result (first differing byte comparison) to a result address. | [`SyscallMemcmp`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/mem_ops.rs#L67) | | `sol_memset_` | Fills `n` bytes of a memory region with a given byte value. | [`SyscallMemset`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/mem_ops.rs#L113) | #### Program data | Syscall | Description | Source | | --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ | | `sol_set_return_data` | Sets return data (max 1,024 bytes) for the current instruction. Readable by the caller after the CPI returns. | [`SyscallSetReturnData`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1354) | | `sol_get_return_data` | Reads the return data set by the most recent CPI. Returns the data length and the program ID that set it. | [`SyscallGetReturnData`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1402) | | `sol_get_processed_sibling_instruction` | Retrieves a previously executed sibling instruction at the same stack height (by reverse index). Returns program ID, data, and account metas. | [`SyscallGetProcessedSiblingInstruction`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1450) | | `sol_get_stack_height` | Returns the current call stack height. Height 1 = top-level instruction; each CPI increments by 1. | [`SyscallGetStackHeight`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1538) | #### Compute | Syscall | Description | Source | | ----------------------------- | --------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | | `sol_remaining_compute_units` | Returns the number of compute units remaining in the transaction budget. Feature-gated. | [`SyscallRemainingComputeUnits`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1803) | #### Epoch stake | Syscall | Description | Source | | --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- | | `sol_get_epoch_stake` | Returns total cluster stake (null pointer) or a specific vote account's delegated stake for the current epoch (SIMD-0133). Feature-gated. | [`SyscallGetEpochStake`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L1974) | #### Memory allocation | Syscall | Description | Source | | ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------- | | `sol_alloc_free_` | Legacy bump allocator for dynamic memory allocation. Disabled for new deployments; only available to programs deployed before the feature gate. | [`SyscallAllocFree`](https://github.com/anza-xyz/agave/blob/v3.1.8/syscalls/src/lib.rs#L735) |