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Computation definitions and MXEs are on-chain accounts that hold rent. When you no longer need them, close them to reclaim that rent. This page covers the close lifecycle, authority rules, and common errors. For a shorter command list, see the deployment guide.
This page covers long-lived MXE and computation-definition accounts. To close per-computation accounts after finalization, use claimComputationRent.

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Computation-definition lifecycle

A computation-definition account moves through the following states: A default CircuitSource::OnChain comp def starts as IncompleteOnChain (is_completed = false) and is not queueable until upload finalization marks it complete. CircuitSource::OffChain and CircuitSource::Local comp defs initialize directly as Active. The two-step gate exists so computations queued before deactivation can drain safely. Calling deactivate-computation-definition blocks new queue_computation calls immediately; existing queued computations must finalize or expire before closing succeeds.

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Deactivation TTL

TTL_SLOTS = 180 (~72s at 400 ms/slot). The TTL is identical to a Solana transaction’s signature lifetime; the constant is shared on purpose. You can close the computation definition any time after deactivation_slot + 180.

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Authority

Circuit sourceWho can deactivate / close
CircuitSource::OnChainupload_auth (the keypair that uploaded the circuit buffers)
CircuitSource::OffChainmxe.authority
CircuitSource::Localmxe.authority
close-mxe always requires mxe.authority. Rent from every close goes back to the signer keypair (-k).

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Closing a computation definition

# 1. Mark the computation definition for closure (irreversible — blocks new queues immediately)
arcium deactivate-computation-definition \
  -o <computation-definition-offset> \
  -p <mxe-program-id> \
  -k <path-to-your-keypair> \
  --rpc-url <your-rpc-url>

# 2. After the TTL (180 slots, ~72s) has passed and no in-flight comps remain, close it
arcium close-computation-definition \
  -o <computation-definition-offset> \
  -p <mxe-program-id> \
  -c <cluster-offset> \
  -k <path-to-your-keypair> \
  --rpc-url <your-rpc-url>
close-computation-definition is the only close command that needs --cluster-offset (-c) — the program enforces mxe.cluster == cluster_offset.

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Incomplete on-chain comp defs skip the TTL

If a CircuitSource::OnChain upload was aborted before finishing, the comp def remains Incomplete and can be closed immediately, without deactivating first. This is the only way out of the two-step gate.

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Raw circuit buffers (on-chain circuits only)

CircuitSource::OnChain comp defs also store circuit bytes in separate buffer accounts indexed by raw_circuit_index. Close each buffer separately with the MXE authority keypair: 
arcium close-computation-definition-buffers \
  -o <computation-definition-offset> \
  -p <mxe-program-id> \
  -i <raw-circuit-index> \
  -k <path-to-your-keypair> \
  --rpc-url <your-rpc-url>
Buffers can be closed when the parent comp def is Deactivated or still Incomplete. Unlike deactivating or closing the parent OnChain comp def, buffer close requires mxe.authority. Off-chain and Local comp defs store no buffers, so this step does not apply to them.

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Reserved comp defs

Each MXE has reserved internal computation definitions (e.g. MxeKeygen, MxeKeyRecoveryInit). You cannot close these directly with close-computation-definition — attempting it errors with CannotCloseReservedComputationDefinition. They are closed atomically by close-mxe.

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LUT entries persist across close

Closing a comp def does not close its address-lookup-table entry. Re-initializing a comp def at the same offset reuses the existing LUT slot, so close + reinit cycles do not pay rent for a new LUT.

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Closing an MXE

arcium close-mxe \
  -p <mxe-program-id> \
  -k <path-to-your-keypair> \
  --rpc-url <your-rpc-url>
close-mxe enforces several preconditions before closing:
  1. MXE must not be in Migration state — abort or resume the migration first.
  2. Keygen must be finalized (MxeKeygenNotFinalized otherwise).
  3. Every user-defined computation definition must be closed first. Only reserved MXE computation definitions may remain (MxeKeygen and, if present, MxeKeyRecoveryInit).
  4. Signer must be mxe.authority.
When the preconditions pass, close-mxe closes the MXE account, the reserved keygen comp def, the keygen computation account, the recovery cluster account, and (if present) the key-recovery-init comp def and computation — all in one transaction. Rent for every closed account returns to the signer.

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Error reference

Anchor program errors are reported as Error Code: <number> where the number is 6000 + <internal offset>. Internal offsets and meanings:
InternalAnchor surfacedNameMeaning
06000InvalidAuthoritySigner is not the authority for this account
96009MxeHasComputationDefinitionsclose-mxe blocked: user comp defs remain
106010MxeKeygenNotFinalizedclose-mxe blocked: keygen not yet finalized
3066306ComputationDefinitionDeactivatedCannot deactivate twice
3076307ComputationDefinitionNotDeactivatedCall deactivate-computation-definition first
3086308ComputationDefinitionHasActiveComputationsA pre-deactivation computation is still in flight
3096309ComputationDefinitionTtlNotPassedWait until deactivation_slot + 180
3106310CannotCloseReservedComputationDefinitionReserved offsets close atomically via close-mxe
7256725CannotCloseMxeDuringMigrationAbort or resume the cluster migration first

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Common mistakes

  • “ComputationDefinitionTtlNotPassed (6309)” — you’re inside the 180-slot window after deactivation. Wait ~72 s and retry.
  • “ComputationDefinitionHasActiveComputations (6308)” — a computation queued before deactivation_slot is still in the execpool. Computations themselves expire after 180 slots; wait for it to finalize or expire and retry.
  • “ComputationDefinitionNotDeactivated (6307)” — you skipped deactivate-computation-definition. Active comp defs cannot be closed directly (the only exception is Incomplete OnChain comp defs).
  • “CannotCloseReservedComputationDefinition (6310)” — you targeted a reserved offset (MxeKeygen, MxeKeyRecoveryInit). Run close-mxe instead; reserved offsets close atomically as part of it.
  • “MxeHasComputationDefinitions (6009)” — close-mxe requires every user-defined comp def to be closed first. Only reserved MXE computation definitions may remain (MxeKeygen and, if present, MxeKeyRecoveryInit).
  • “CannotCloseMxeDuringMigration (6725)” — there’s a migrate-cluster in flight. --resume or --abort it, then retry.
  • “InvalidAuthority (6000)” — for comp defs, OnChain accepts upload_auth while OffChain/Local require mxe.authority. close-mxe always requires mxe.authority.
  • “InvalidAuthority (6000)” on buffer close — close-computation-definition-buffers always requires mxe.authority, even for OnChain comp defs uploaded by a different upload_auth.
  • “close-computation-definition-buffers did nothing” — your comp def is OffChain or Local. There are no buffer accounts to close; skip the step.
  • “Forgot --cluster-offset on close-computation-definition” — only that command needs -c; the program rejects mismatches against mxe.cluster.

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What’s next?

Deployment

Deploy, migrate, and close MXEs from the CLI.

Computation Definition Accounts

How comp defs are created and initialized.