NEP-611: Pending Transaction Queue by robin-near · Pull Request #611 · near/NEPs

robin-near · 2025-05-30T23:36:54Z

In the near future of the Near blockchain, we foresee that via the SPICE project, transaction and receipt execution will become decoupled from the blockchain itself; they will no longer run in lockstep. Instead, transactions will be included in the blocks first, and then execution will follow later.

This inherently introduces a problem that we must accept transactions before we know whether they are valid. Today, when a chunk producer produces a chunk containing a transaction, it can verify using the current shard state that the transaction has a valid signature, has enough balance, and a valid nonce. But as execution becomes asynchronous, we no longer have the current shard state to verify the
transactions against.

This NEP proposes a mechanism called the Pending Transaction Queue to solve this problem.

birchmd

Thanks for bringing this up! It is good to think about how to prevent possible DoS attacks under SPICE.

birchmd · 2025-06-02T13:23:05Z

+#### Access Key Parallelism Restriction
+We now restrict the ability to send multiple parallel pending transactions with Access Keys.
+
+Specifically, for any given account $A$ with any number of access keys, the total number of access key transactions in the pending transaction queue whose sender is $A$ cannot exceed $P_{\mathrm {max}}$, a


Is this enough to prevent the attack described above? Instead of having one account they send many transactions to, it could be many accounts they send only a few transactions to each.

The idea is that the amount of block space the attacker consumes vs amount of gas the attacker has to pay, i.e. the "waste amplification factor", is unbounded in the attack mentioned in the NEP, but only O(1) with a maximum parallelism. It's then still possible to attack, but the attack would cost a proportional amount of gas - just cheaper than it is today - which isn't a very great incentive to mount the attack (given that the attack is only a DoS).

…thout contract.

See near/NEPs#611 This PR adds the GasKey trie key. In subsequent PRs we will introduce a new transaction type to accept gas key transactions, and to implement the gas key actions.

gagdiez · 2025-07-16T13:10:17Z

Hi @robin-near (or anyone who is interested in championing this NEP forward) – we are cleaning the NEP backlog and noticed that this PR still has some incomplete sections: particularly, it has a "TODO: Other things". Therefore, we are labeling this PR as "Needs author revision."

Please ping the @near/nep-moderators once you are ready for us to review it. We typically close NEPs that are inactive for more than two months, so please let us know if you need more time.

garikbesson · 2025-09-22T11:29:18Z

Because there has been no activity from the author for more than 3 months, I'm marking the proposal as RETRACTED. Please feel free to open it again if you'd like to continue working on it.

Gas keys ([NEP-611](near/NEPs#611)) allow access keys to carry a NEAR balance dedicated to paying for gas, separate from the account's main balance. This PR implements Rosetta Construction API support for `TransferToGasKey` and `WithdrawFromGasKey` actions, enabling bidirectional conversion between NEAR actions and Rosetta operations. - New operations: `InitiateTransferToGasKey`, `TransferToGasKey`, `InitiateWithdrawFromGasKey`, `WithdrawFromGasKey` - Each gas key action maps to a pair of Rosetta operations (initiate + main), following the existing pattern used by `Transfer`, `AddKey`, etc. - `TransferToGasKey` is non-SIR-compatible (sender != receiver), `WithdrawFromGasKey` is SIR-compatible - Roundtrip bijection test updated to cover both new action types

Gas keys ([NEP-611](near/NEPs#611)) allow access keys to carry a NEAR balance dedicated to paying for gas, separate from the account's main balance. This PR adds Rosetta Data API support for tracking gas key balances, building on the action encoding from #15100. At a high level, uses `StateChangesRequestView::AllAccessKeyChanges` to get changes to gas key balances, including when they are deleted. Then, adding a new `SubAccount` type, which represents the aggregate gas key balance for an account on the Rosetta side. - Add `SubAccount::GasKey` for querying aggregate gas key balance via `/account/balance`. - Track per-key gas key balance changes by observing access key state changes in each block - Attribute balance diffs to their causal receipt/transaction with `transfer_fee_type` metadata: `GasPrepayment` for `TransactionProcessing`,`GasRefund` for system predecessor - Handle key deletion by emitting a `GasKeyBalanceBurnt` operation for the remaining balance - Add test covering transfer-in, refund, gas usage, key deletion, and gas prepayment scenarios

gagdiez · 2026-02-26T16:48:23Z

Hi everyone! seeing that some members of the WG voted, and by the request of @walnut-the-cat, we are moving forward to meet and vote this NEP

@robin-near, @jakmeier, @matejpavlovic, @darioush if you could share your availability here we will try to find some time that works for everyone

@robin-near / @darioush would be awesome if one of you could present a high level explanation of the NEP. No need to have a full presentation, just 1 - 3 slides, enough overview for people to understand the gist of it.

Thank you everyone!

darioush · 2026-02-26T17:32:30Z

@gagdiez Thanks for setting up the scheduling. I would be happy to present a few slides.

gagdiez · 2026-03-02T14:29:43Z

As the moderator, I would like to thank @robin-near for submitting this NEP-Category, and for the @near/wg-protocol working group members for your review. We are scheduling a Protocol Working group meeting tomorrow, where this NEP can enter the final voting stage.

Anyone can discuss the technical details by adding your comments to this discussion. And join the call to learn about the final decision and how to get more involved.

cc @jakmeier @walnut-the-cat @darioush @birchmd

Meeting Info
📅 Date: Tuesday, March 3, 6pm UTC
✏️ Register

Co-Authored-By: Claude Opus 4.6 <[email protected]>

gagdiez · 2026-03-05T13:04:06Z

Thank you to everyone who attended the Protocol Working Group meeting! The working group members reviewed the NEP and reached the following consensus:

Status: Approved

Meeting Recording: https://youtu.be/oJgyyT37mxw

@darioush thank you for authoring this NEP!

Next Steps:

@darioush To finish tiding up the NEP - if there is anything left to be done
@near/nep-moderators To approve and merge the NEP

Co-Authored-By: Claude Opus 4.6 <[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.

Adds a 2.13.0 changelog entry for the new `DelegateV2` meta-transaction action (`ProtocolFeature::DelegateV2`, protocol version 85), which lets gas keys ([NEP-611](near/NEPs#611)) sign relayed meta transactions. ([#15904](#15904), [#15905](#15905), [#15906](#15906)) Sorry I forgot this as part of the feature.

Draft NEP for pending transaction queue.

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Revise the NEP so that access keys are not restricted for accounts wi…

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…thout contract.

trechriron deployed to robin/611 - nomicon PR #611 June 6, 2025 21:01 — with Render View deployment

robin-near mentioned this pull request Jun 9, 2025

Introduce GasKey to the trie. near/nearcore#13687

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Merge branch 'master' into robin/611

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This was referenced Oct 27, 2025

spice: Implement pending transaction queue near/nearcore#13586

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spice: Pending transaction queue NEP near/nearcore#14499

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spice: Implement gas keys near/nearcore#14500

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revision and completing incomplete sections

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darioush reopened this Nov 21, 2025

github-project-automation Bot moved this from Shipped 🚀 to NEW❗ in DevRel Nov 21, 2025

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darioush mentioned this pull request Feb 25, 2026

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

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gagdiez changed the title ~~Draft NEP for pending transaction queue.~~ NEP-611: Pending Transaction Queue Feb 26, 2026

gagdiez added S-voting/needs-wg-voting-indication A NEP in the VOTING stage that needs the working group voting indication. and removed S-review/needs-sme-review A NEP in the REVIEW stage is waiting for Subject Matter Expert review. labels Feb 26, 2026

gagdiez and others added 2 commits March 3, 2026 19:27

Merge branch 'master' into robin/611

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fix lint

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r-near mentioned this pull request Mar 3, 2026

NEP-611: Pending Transaction Queue & Gas Keys — DevEx library changes near/devex#43

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doc: add transaction flow diagram to nep-0611

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Co-Authored-By: Claude Opus 4.6 <[email protected]>

gagdiez approved these changes Mar 5, 2026

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gagdiez added S-approved A NEP that was approved by a working group. and removed S-voting/needs-wg-voting-indication A NEP in the VOTING stage that needs the working group voting indication. labels Mar 5, 2026

doc: rename diagram to pending-tx-flow.svg

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Co-Authored-By: Claude Opus 4.6 <[email protected]>

darioush force-pushed the robin/611 branch from 251c6f3 to f1254e0 Compare March 5, 2026 13:19

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darioush mentioned this pull request Jun 17, 2026

doc(changelog): add DelegateV2 meta-transaction entry near/nearcore#15934

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