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This page explains what your app pays when it delegates an account to an Ephemeral Rollup (ER), commits that account back to Solana, and later undelegates it.

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The short version

There are two separate fee systems:
  1. A deposit on Solana. You fund this deposit when you delegate an account. When you undelegate, MagicBlock takes the session and commit charges from it and returns anything left over.
  2. A live commit limit inside the ER. Without a delegated fee payer, an account can commit 10 times. For a longer session, add a delegated fee payer and magic_fee_vault. This removes the 10-commit stop. The fee payer starts paying an extra live fee on commit 26.
These systems work together. A commit with no immediate fee can still be charged against the Solana deposit when the account is undelegated.
The values on this page were checked against the source on August 20, 2026.

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Current prices

One SOL contains 1 billion lamports. Normal ER transactions cost 0 in the current release. Solana transaction fees are separate from the prices above.

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1. The deposit you fund on Solana

Delegating an account creates two small Solana accounts: a delegation record and delegation metadata. The delegation payer funds both accounts so they are rent-exempt. Think of that money as a refundable balance, not a one-time fee that buys unlimited commits. When you undelegate, MagicBlock calculates the charge:
MagicBlock takes no more than the amount held in the two deposit accounts. It sends the unused amount back to the wallet recorded as the rent_payer when the account was delegated. In practical terms:
  • even a session with no commit can use up to 300,000 lamports from the deposit;
  • commit 1 adds no commit charge;
  • commits 2, 3, 4, and so on add 100,000 lamports each;
  • if the calculated charge is larger than the deposit, MagicBlock takes the deposit but does not create a debt or fail undelegation;
  • any money left in the deposit is refunded.
The exact deposit size varies because it depends on Solana rent, the account’s stored seeds, and any actions included with the delegation.

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2. Committing without a fee payer

  • Commits 1 through 10 are accepted.
  • Commit 11 fails with custom error 0xA0000000.
  • The accepted commits are still included in the deposit charge when you undelegate.
A final commit-and-undelegate can still run after the limit so the account is not trapped inside the ER. It does not allow more normal commits.

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3. Committing with a fee payer

For a longer session, provide:
  • a delegated account that will pay the fees; and
  • the magic_fee_vault that belongs to the ER validator you are using.
This path does not stop after 10 commits. Instead:
  • commits 1 through 25 have no extra live commit fee;
  • commit 26 is the first live commit fee;
  • commit 26 and every later commit cost 100,000 lamports per committed account.
Live fees are taken from the delegated fee payer when the bundle is scheduled. Deposit charges are calculated separately when the account is undelegated, so your app may pay both. If one bundle commits several accounts, MagicBlock checks each account separately. For example, a bundle that contains two accounts on commit 26 costs 200,000 lamports in live commit fees. If the fee payer cannot cover the full charge, the instruction fails with InsufficientFunds. No partial payment is taken.
The committed account and the fee payer do not have to be the same account. If your app pays for users, set spending limits and rate limits so one user cannot drain the shared payer.

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Worked examples

The examples below do not include normal Solana transaction fees. D means the deposit balance just before undelegation.

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One commit, then undelegate

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Ten simple commits, then undelegate

An 11th simple commit fails before it is scheduled.

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Twenty-six commits with a delegated fee payer

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Keeping the fee payer funded

Use lamportsDelegatedTransferIx to add lamports to a delegated fee payer. You submit the top-up transaction on Solana, and the Ephemeral SPL Token program moves the balance into the ER. See the top-up example. Include these costs in your budget:
  • the lamports you are transferring;
  • the top-up helper’s current 300,000-lamport setup charge;
  • the normal Solana transaction fee.
The top-up setup charge and the 300,000-lamport delegation session charge are different charges. They currently happen to have the same value.

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Base Actions and callbacks

A Base Action is an instruction that the ER asks MagicBlock to execute on Solana after a commit. On the fee-payer path, its price depends on the compute units requested by the action:
For example:
  • one action requesting 200,000 compute units costs 10,000 lamports;
  • two such actions cost 20,000 lamports.
Adding a callback costs another 5,000 lamports. The callback’s requested compute units are not included in the Base Action calculation above.

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Refundable Ephemeral Account storage

Ephemeral Accounts exist only inside the ER and never commit to Solana. They use a separate, refundable storage balance:
The sponsor provides this balance when the account is created or grows. The corresponding amount is returned to the sponsor when the account shrinks or closes. For example:
  • an account with no data reserves 1,920 lamports;
  • an account with 1,000 bytes of data reserves 33,920 lamports.
See Ephemeral Accounts for the full account lifecycle.

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Other balance movements that are not app fees

When a commit changes an account’s lamport balance, MagicBlock must make the ER balance and Solana balance match. Lamports may move between the account and the validator during this settlement. This is balance reconciliation, not an extra fixed or percentage fee. The older two-step commit path also uses temporary Solana accounts. The validator funds them and gets the unused balance back after finalization. These are validator operating costs, not additional app fees. Validators also pay Solana priority fees when submitting commit transactions. Those operator costs are separate from the Base Action price charged to an app. If a delegated account has no data and no lamports, the Delegation Program may add 890,880 lamports to keep it rent-exempt. That money funds the account; it is not protocol revenue.

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Common errors

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Where the fees go

When the deposit is settled, about 10% of the collected amount goes to the protocol fee vault and about 90% goes to the validator fee vault. Small rounding differences are possible. When a validator later withdraws its accumulated fees, 10% of that withdrawal goes to the protocol and the validator receives the rest. Validators wait until their vault balance is above 100,000,000 lamports before automatically withdrawing. This threshold is only for batching; it is not an app fee.

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Verify the current numbers

The fee rules are split between two repositories. Check both when verifying production behavior: