Macro anchor_lang::declare_program

declare_program!() { /* proc-macro */ }

Declare an external program based on its IDL.

The IDL of the program must exist in a directory named idls. This directory can be at any depth, e.g. both inside the program’s directory (<PROGRAM_DIR>/idls) and inside Anchor workspace root directory (<PROGRAM_DIR>/../../idls) are valid.

Usage

declare_program!(program_name);

This generates a module named program_name that can be used to interact with the program without having to add the program’s crate as a dependency.

Both on-chain and off-chain usage is supported.

Use cargo doc --open to see the generated modules and their documentation.

Note

Re-defining the same program to use the same definitions should be avoided since this results in a larger binary size.

A program should only be defined once. If you have multiple programs that depend on the same definition, you should consider creating a separate crate for the external program definition and reusing it in your programs.

Example

A full on-chain CPI usage example can be found here.