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Architecture · easy

7. Cross-Program Invocations (CPIs)

Composability and inter-program calls.

1 min read3 questionsup to 50 XPtopic 7/100

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A Cross-Program Invocation (CPI) occurs when one program calls an instruction on another on-chain program (such as calling the SPL Token program to transfer tokens). CPIs can forward caller privileges or sign using PDA seeds with invoke_signed.

How to study this topic

  1. 1. Read the explanation once end to end, skipping the code.
  2. 2. Re-read the code snippets and say out loud what each line does.
  3. 3. Answer the quiz without scrolling back — that is the real check.
  4. 4. Read every explanation, even for the answers you got right.

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Check your understanding

  1. 1. What is a CPI on Solana?

  2. 2. What depth limit does the Solana runtime enforce on nested CPIs?

  3. 3. How does a program invoke another program with PDA authorization?

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