feat: burn gas key balances on key/account deletion by darioush · Pull Request #14933 · near/nearcore

darioush · 2026-01-26T22:53:46Z

Since NEAR has an accounting of total supply it is necessary to track tokens burnt in gas key deletions.

darioush · 2026-01-26T23:03:07Z

    state_update: &mut TrieUpdate,
    account_id: &AccountId,
-) -> Result<(), StorageError> {
+) -> Result<Balance, StorageError> {


We can make a separate utility function instead, it seemed easier to return it here since we already iterate keys.

codecov · 2026-01-26T23:03:49Z

Codecov Report

❌ Patch coverage is 84.14634% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 68.76%. Comparing base (53f25e8) to head (765423b).
⚠️ Report is 17 commits behind head on master.

Files with missing lines	Patch %	Lines
core/store/src/utils/mod.rs	57.14%	3 Missing and 3 partials ⚠️
runtime/runtime/src/actions.rs	0.00%	1 Missing and 3 partials ⚠️
runtime/runtime/src/lib.rs	71.42%	0 Missing and 2 partials ⚠️
runtime/runtime/src/access_keys.rs	98.24%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #14933      +/-   ##
==========================================
+ Coverage   68.74%   68.76%   +0.01%     
==========================================
  Files         918      918              
  Lines      200153   200301     +148     
  Branches   200153   200301     +148     
==========================================
+ Hits       137605   137732     +127     
- Misses      56627    56636       +9     
- Partials     5921     5933      +12

Flag	Coverage Δ
pytests-nightly	`1.30% <0.00%> (-0.01%)`	⬇️
unittests	`68.46% <84.14%> (-0.01%)`	⬇️
unittests-nightly	`68.27% <84.14%> (+0.02%)`	⬆️

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Copilot

Pull request overview

This PR adds explicit accounting for tokens burned when gas keys (or accounts containing gas keys) are deleted, so the protocol can correctly track total supply changes attributable to gas-key balance destruction.

Changes:

Add tokens_burnt: Balance to ActionResult, including merge/default behavior.
Burn and accumulate remaining gas-key balances on DeleteKey (gas key) and DeleteAccount, and incorporate it into receipt tokens_burnt.
Update remove_account to return total gas-key balances removed; add unit tests and expand ExecutionOutcome::tokens_burnt docs.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
runtime/runtime/src/lib.rs	Adds `ActionResult.tokens_burnt` and folds it into receipt burn accounting.
runtime/runtime/src/actions.rs	Collects gas-key balances burned during account deletion via updated `remove_account`.
runtime/runtime/src/access_keys.rs	Burns gas-key balances on gas-key deletion; adds tests for key/account deletion burn totals.
core/store/src/utils/mod.rs	Changes `remove_account` to compute/return total gas-key balances removed.
core/primitives/src/transaction.rs	Updates `ExecutionOutcome::tokens_burnt` documentation to mention gas-key deletion burns.

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Copilot · 2026-01-29T21:38:09Z

            .unwrap();
        tx_burnt_amount = safe_add_balance(tx_burnt_amount, gas_refund_result.price_surplus)?;
        tx_burnt_amount = safe_add_balance(tx_burnt_amount, gas_refund_result.refund_penalty)?;
+        tx_burnt_amount = safe_add_balance(tx_burnt_amount, result.tokens_burnt)?;


result.tokens_burnt is added into tx_burnt_amount unconditionally, but state changes from deleting gas keys/accounts are rolled back when result.result is Err (state_update.rollback() above). This can report/charge burned gas-key balances for receipts that ultimately fail and revert, leaving the gas keys (and balances) intact. Consider only adding result.tokens_burnt when the receipt commits (e.g., gate on result.result.is_ok()), and add a regression test for a multi-action receipt where a gas-key deletion is followed by a failing action.

Suggested change

tx_burnt_amount = safe_add_balance(tx_burnt_amount, result.tokens_burnt)?;

if result.result.is_ok() {

tx_burnt_amount = safe_add_balance(tx_burnt_amount, result.tokens_burnt)?;

}

@pugachAG This seems like legit issue, I made this change and added a test.
Please let me know what you think.

legit issue indeed, the test LGTM, thanks!

Co-authored-by: Copilot <[email protected]>

new code added

darioush · 2026-01-30T01:58:23Z

+            self.tokens_burnt = self
+                .tokens_burnt
+                .checked_add(next_result.tokens_burnt)
+                .ok_or(IntegerOverflowError)?;


@pugachAG I think this is the correct fix for the issue. I think the result should have tokens_burnt = 0 if it is Err, so fixing it in merge makes more sense to me.
We can add the prior check as a defensive check too. Please let me know what you think.

I don't see fundamentally why failed action cannot burn any tokens in the future use cases, so I'd rather make sure that tokens_burnt is properly set when handling the action. Not a strong opinion though, up to you.

pugachAG · 2026-01-30T09:16:01Z

+            self.tokens_burnt = self
+                .tokens_burnt
+                .checked_add(next_result.tokens_burnt)
+                .ok_or(IntegerOverflowError)?;


I don't see fundamentally why failed action cannot burn any tokens in the future use cases, so I'd rather make sure that tokens_burnt is properly set when handling the action. Not a strong opinion though, up to you.

pugachAG · 2026-01-30T09:16:48Z

            .unwrap();
        tx_burnt_amount = safe_add_balance(tx_burnt_amount, gas_refund_result.price_surplus)?;
        tx_burnt_amount = safe_add_balance(tx_burnt_amount, gas_refund_result.refund_penalty)?;
+        tx_burnt_amount = safe_add_balance(tx_burnt_amount, result.tokens_burnt)?;


legit issue indeed, the test LGTM, thanks!

Since NEAR has an accounting of total supply it is necessary to track tokens burnt in gas key deletions. --------- Co-authored-by: Copilot <[email protected]>

# Gas Keys ([NEP-611](near/NEPs#611)) Gas keys are a new type of access key that carries a pre-funded NEAR balance and multiple independent nonce sequences. When a transaction is signed with a gas key, gas costs are deducted from the gas key's balance rather than the signer's account balance (deposits like NEAR transfers still come from the account). ## Why do we need gas keys? - Enabling SPICE without a DoS vector. The SPICE project (Separation of Execution from Consensus) decouples transaction execution from block production: transactions are included in blocks first, and executed asynchronously later. This means chunk producers can no longer verify account balances at inclusion time. An attacker could drain an account's balance in one transaction, then flood the chain with many transactions signed by that account. All would be accepted (since execution hasn't caught up), consuming block space for free when they inevitably fail. Gas keys close this gap by requiring gas to be pre-committed in the key itself, so chunk producers can verify gas availability without access to the latest state. - Parallel transaction submission. Today, programmatic users who submit many transactions in parallel must manage multiple access keys (each with its own nonce sequence). A gas key supports up to 1,024 independent nonce slots via a single key, removing that complexity. # Context - NEP (if exists): near/NEPs#611 - Implementation: - near#14868 - near#14869 - near#14883 - near#14891 - near#14892 - near#14911 - near#14924 - near#14925 - near#14930 - near#14933 - near#14969 - near#14985 - near#15033 - near#15034 - near#15067 - near#15068 - near#15100 - near#15101 - near#15186 # Testing and QA - unit tests - test-loop: https://github.com/near/nearcore/blob/master/test-loop-tests/src/tests/gas_keys.rs - forknet (automated): near#15207 - forknet (manual testing, planned) # Checklist - [x] Link to nightly nayduck run: https://nayduck.nearone.org/#/run/4756 - [x] Update CHANGELOG.md to include this protocol feature in the `Unreleased` section.

feat: burn gas key balances on key/account deletion

e75c8d2

darioush requested review from attila0x2A and pugachAG January 26, 2026 23:02

darioush marked this pull request as ready for review January 26, 2026 23:02

darioush requested a review from a team as a code owner January 26, 2026 23:02

darioush commented Jan 26, 2026

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pugachAG previously approved these changes Jan 29, 2026

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Comment thread core/primitives/src/transaction.rs Outdated

update comment

5ab1fff

Copilot AI review requested due to automatic review settings January 29, 2026 21:27

Copilot started reviewing on behalf of darioush January 29, 2026 21:27 View session

darioush enabled auto-merge January 29, 2026 21:27

darioush added this pull request to the merge queue Jan 29, 2026

Copilot AI reviewed Jan 29, 2026

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darioush removed this pull request from the merge queue due to a manual request Jan 29, 2026

darioush and others added 3 commits January 29, 2026 13:41

Update runtime/runtime/src/lib.rs

e9d3eaa

Co-authored-by: Copilot <[email protected]>

Update core/primitives/src/transaction.rs

9640c06

Co-authored-by: Copilot <[email protected]>

add regression test

a8464c5

darioush requested a review from pugachAG January 29, 2026 22:58

better fix?

765423b

darioush commented Jan 30, 2026

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pugachAG approved these changes Jan 30, 2026

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darioush added this pull request to the merge queue Jan 30, 2026

Merged via the queue into near:master with commit 425a4b1 Jan 30, 2026
53 of 54 checks passed

darioush deleted the burn-tokens-delete branch January 30, 2026 13:48

darioush mentioned this pull request Feb 25, 2026

feat(gas-keys): stabilize gas keys at protocol version 85 #15183

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