Module introspect 

Instruction introspection – stack height and sibling instruction access.

These syscalls are critical for security patterns that no framework wraps:

• CPI guard: Detect if the current instruction is running inside a CPI call (stack height > 1). Prevents unauthorized composition – e.g., a governance instruction that must be top-level only.

• Ed25519 signature verification: Check that a previous instruction in the same transaction was to the Ed25519 precompile with specific data. This is how on-chain programs verify off-chain signatures without heavy crypto libraries.

• Secp256k1 recovery: Same pattern for Ethereum-compatible signatures.

No existing framework (pinocchio, Anchor, Steel, Quasar) wraps these syscalls with ergonomic APIs. Programs that need them write raw unsafe glue every time.

Structs

ProcessedInstruction

Metadata about a previously processed sibling instruction.

Constants

ED25519_PROGRAM_ID

Well-known precompile address for Ed25519 signature verification.

SECP256K1_PROGRAM_ID

Well-known precompile address for Secp256k1 signature recovery.

Functions

get_processed_instruction

Retrieve a previously processed sibling instruction from the current transaction.

get_stack_height

Get the current instruction stack height.

is_cpi

Returns true if the current instruction is running inside a CPI.

is_top_level

Returns true if the current instruction is at the top level (not running inside a CPI).

require_cpi

Require that the current instruction IS inside a CPI.

require_ed25519_instruction

Check that a previous sibling instruction was to the Ed25519 precompile.

require_secp256k1_instruction

Check that a previous sibling instruction was to the Secp256k1 precompile.

require_top_level

Require that the current instruction is NOT a CPI call.