x402 SVM compute-budget triage

A source-linked operator checklist for x402 PR #3155: four affected paths, six diagnostic cases, and a compact evidence template. Read-only preparation and proposed tests; no live transaction results are claimed. Reviewed September 10, 2026.

Use this when a Solana x402 integration changes compute settings or reports a failed worker payout. You need the installed package version, builder entry point, sanitized error response, and relevant transaction or channel identifiers. Missing evidence stays unknown.

Establish what actually changed

The upstream PR merged on August 14 at commit 167a828e8319aa7b403f4f4312489e9cffadff10. Its TypeScript SVM upto builders reserve smaller, explicit compute budgets. A merged change does not establish which version your gateway or facilitator runs.

Trace each deployed route before changing settings:

The client rejects limits above 400,000 CU and prices above 5,000,000 microlamports per CU. A zero facilitator price omits its price instruction. These are revision-specific implementation facts, not recommendations to use the maximum.

Sources: channel open, facilitator channel, cleanup manager.

Classify the failure

Use isolated fixtures or a local fork for the following proposed tests. Preserve recipient, ownership, mint and voucher checks in every control.

1. Missing payout binding. Record the exact error and lifecycle stage. Compare a fixture without a binding against one with the correctly verified, controlled Solana address. A larger compute budget cannot create that binding.
2. Missing USDC associated token account. Compare missing, present and unreadable account states. RPC failure is not proof of absence. Check the deployed program's distribution behavior before assuming it creates an account automatically.
3. Recipient changed after channel creation. Compare the current profile with the funded channel's committed distribution. Updating a profile cannot rewrite an immutable channel recipient. Test recovery separately from retries.
4. Channel session unavailable. Distinguish a missing authorized signer from a compute error. A replacement session key does not authorize an older channel. Check that settlement retries reconcile a prior payment only once.
5. Actual compute exhaustion. Record requested units, units consumed and execution logs. Run the same isolated fixture with an appropriate higher-limit control. Token-2022 transfer hooks or atypical distributions may need measured overrides.
6. Settlement not yet verified. Delay transaction visibility in the fixture, then restore it. A successful transaction that credits the wrong recipient must remain unpaid in application accounting.

For Execution Market specifically, its Solana reference distinguishes payout binding, worker-account checks and late settlement. It documents a treasury redirect when a channel distribution lacks the recipient ATA. Verify the deployed path; do not substitute an SDK example's behavior for that program. EVM escrow routes are outside this SVM change.

Produce a reviewable record

Use one record per failing path:

{
  "checked_at": "ISO-8601 UTC",
  "dependency_commit": "verified commit or null",
  "builder_entry_point": "verified path or null",
  "lifecycle_stage": "open | settle | cleanup | reclaim",
  "error_code": "exact sanitized value",
  "recipient_binding_matches": null,
  "token_account_verified": null,
  "requested_cu": null,
  "consumed_cu": null,
  "isolated_control_result": "not run",
  "payment_verified": false,
  "evidence_urls": []
}

Resolve unknowns from evidence, not from the transaction's success flag alone. For a receipt, check the chain, mint, destination account and owner, amount, finality, and relation to the job or channel. Exclude private keys, session secrets and reusable vouchers.

This guide reviews public source and documentation. It does not claim to reproduce a private fleet's payout deadlock, validate a deployed integration, or prove that changing CU fixes a 409 response.