EIP complexity assessment

EIP-7709: Read BLOCKHASH from Storage and Update Cost

Assessed in Hegotá. The score describes the EIP text available at the snapshot, not the EIP as it stands today.

ProspectiveHegotáSnapshot 2026-08-25PFI at snapshotLayers: execution

LLM Completescore 20

Human Available in open PRscore 17 · Checklist revision 2· ethspecs/pm #120

Other checklist versions (1)

Pull request #73 · Checklist revision 1 · total 4

LLM · Checklist revision 22026-08-26 · Original snapshot · 20 Human · Checklist revision 2Available in open PR · 17 CompareHuman vs LLM · same checklist revision

Evaluated on: 2026-08-26 · Spec revision: 2026-08-25 · ac450a4ab2 · Inclusion status at snapshot: PFI

Scope at the cutoff. Execution-layer assessment of the draft EIP-7709 snapshot. The proposal changes the existing BLOCKHASH opcode so that in-window lookups have the gas, warming, and state-access-recording effects of an SLOAD from the EIP-2935 history contract's ring-buffer slot, while preserving the existing return-value window.

20MediumMedium

Evaluator: LLMChecklist v2
Confidence: Medium
Under-specified at assessment cutoff: Yes — 4 criteria affected
Plausible range: 18–21 (Medium)
Snapshot: 2026-08-25 · EIP revision ac450a4ab2 (2026-08-25)

Score bands · Checklist revision 2

Low <12
Medium 12–22
High ≥23

28 criteria scored 0–3 (4 in exceptional cases; cross-EIP interactions is uncapped); nominal maximum 84.

Complexity profile

Each segment is one criterion's contribution to the LLM total. Hover or focus a segment for its score and rationale.

Top complexity drivers

Modified opcodes3
Edge/boundary conditions3
Unspecified behavior requiring cross-client consensus3
Security risks2

Under-specified at assessment cutoff: Yes

The EIP text available at the assessment cutoff left material behavior unresolved. The affected criteria and the plausible total range record that uncertainty.

Why: The draft fixes the result, slot, and required SLOAD-like effects, but does not explicitly specify their ordering relative to the original BLOCKHASH charge at insufficient-gas boundaries. It also leaves the fork timestamp and concrete satisfaction of the EIP-2935 history-age prerequisite unresolved.

Plausible total

18–21
recorded score 20 · plausible tiers Medium

Affected criteria (4)

State-access ordering within opcode execution (1)
Edge/boundary conditions (3)
Cross-EIP interactions (2)
Unspecified behavior requiring cross-client consensus (3)

Unresolved questions at the cutoff (3)

In what exact order are the base BLOCKHASH charge, cold/warm determination, SLOAD charge, state-access recording, and slot warming applied when available gas ends between steps?
What FORK_TIMESTAMP will be used, and how is the requirement for at least 256 prior EIP-2935 blocks (or genesis activation) guaranteed for each activated network?
If that activation-age assumption is violated, is the value read from the unfilled history slot authoritative, or must clients apply another behavior?

Notable ambiguities noted by the assessor (3)

“Entire semantics and effects of SLOAD” is clear about the required effect set but not about its placement relative to the pre-existing BLOCKHASH charge.
Three resolution strategies are allowed, so clients must demonstrate identical gas, warming, and access-recording behavior without a single prescribed execution path.
The activation section states prerequisites as assumptions and does not normatively define behavior for a deployment that violates them.

Criterion breakdown

EIP-7709 Hegotá: LLM criterion scores and rationale
Criterion	Score	Why this score	Evidence / uncertainty
Modified opcodes	3	Although its returned value is preserved, at least one pre-existing opcode's observable behavior beyond gas is modified, invoking the rubric's binary score of 3.	eip.md · § Specification, resolve_blockhash pseudocode and SLOAD-effects list Existing BLOCKHASH gains non-gas behavioral effects: state-slot access, slot warming, and active-fork state-access recording for in-window arguments. Confidence: High Uncertainty: The precise ordering of those effects is unresolved but their introduction is explicit.
Edge/boundary conditionsUnder-specified	3	Multiple boundary-prone mechanisms interact, and the in/out-of-window boundary requires an elevated matrix across gas sufficiency, cold/warm status, repeated access, access recording, and activation history.	eip.md · § Specification, resolve_blockhash pseudocode; § Activation; § Test Cases Cases span both edges of the 256-block serve window, a distinct 8191-slot modulus, cold versus warm repetition, zero-effect out-of-window execution, and activation only after enough EIP-2935 history or at genesis. Confidence: High Uncertainty: The package specifies representative cases but not the complete cross-product or the handling of an incorrectly spaced activation.
Unspecified behavior requiring cross-client consensusUnder-specified	3	A previously non-state-accessing opcode gains consensus-observable access records and warming. The unspecified charge/access sequence can produce different observable results at gas boundaries and therefore requires cross-client agreement and re-baselining.	eip.md · § Specification, resolve_blockhash pseudocode and SLOAD-effects list; § Test Cases bullets 1-4 The text requires the original BLOCKHASH charge plus SLOAD charging, warming, and access recording, but does not explicitly sequence those actions at insufficient-gas boundaries. eip.md · Front matter status; § Specification parameter table; § Activation The proposal is Draft, leaves FORK_TIMESTAMP TBD, and assumes either at least 256 blocks of prior EIP-2935 activation or activation at genesis. Confidence: Medium Uncertainty: Referring to the entire active-fork SLOAD semantics may settle part of the sequence, but the placement of the existing BLOCKHASH charge relative to that sequence is not explicit.
Security risks	2	The mechanism touches a limited set of existing consensus-critical components and slightly alters resource and access-state assumptions, warranting targeted review and fuzzing.	eip.md · § Backwards Compatibility; § Security Considerations The proposal significantly increases in-window BLOCKHASH gas and refers security considerations to EIP-2935 rather than supplying an independent analysis. eip.md · § Specification, SLOAD-effects list Correctness spans opcode execution, gas, warming, state access recording, and history-contract storage. Confidence: Medium Uncertainty: The snapshot gives no EIP-7709-specific threat analysis beyond inheriting EIP-2935 considerations.
Performance risks	2	The cost can be microbenchmarked, but end-to-end effects depend on state/cache and access-recording behavior; impact is limited to in-window BLOCKHASH execution.	eip.md · § Motivation; § Specification, resolution alternatives and SLOAD-effects list; § Rationale Existing BLOCKHASH execution is coupled to state-access machinery and witness recording, while clients may implement resolution by direct SLOAD, system call, or maintained history. Confidence: Medium Uncertainty: The permitted implementation choices leave concrete performance costs client-dependent.
Cross-EIP interactionsUnder-specified	2	Coordinated testing is required with EIP-2935 and its EIP-2929 cold/warm behavior, plus whatever active-fork access-recording rule applies; the dependency is strong but localized.	eip.md · Front matter requires field; § Activation; § Backwards Compatibility; § Test Cases bullets 5-6 EIP-7709 requires EIP-2935, relies on its populated ring buffer, and needs direct contract access to retain normal execution effects. supporting/eip-2935.md · § Specification > Gas costs The history system update does not warm its account or slots under EIP-2929, so later access follows the normal cold/warm rules that EIP-7709 imports. Confidence: High Uncertainty: The active-fork state-access-recording dependency is not identified by EIP number in the package. Interacting EIPs: EIP-2935, EIP-2929
Modified system contracts	1	The pre-existing history contract has a minor indirect gas-context effect: a prior BLOCKHASH can warm its storage slot for later access, without code or state modification.	eip.md · § Specification, resolution alternatives and SLOAD-effects list; § Reading from the System contract No history-contract code or persistent state is changed, but BLOCKHASH now reads its slot and must warm that slot even if a client resolves by another method. supporting/eip-2935.md · § Gas costs Normal calls to the history contract pay account and slot warming costs because its block-start system update does not warm them. Confidence: Medium Uncertainty: Clients may avoid executing the contract, but must reproduce the same warming effect.
EVM Gas rule changes	1	The gas accounting of an existing opcode is updated by composing it with the existing SLOAD schedule; no separate new gas-accounting mechanism is defined.	eip.md · § Abstract; § Specification > Gas costs; § Test Cases bullets 2-4 In-window BLOCKHASH keeps its own charge and additionally applies cold or warm SLOAD cost for the corresponding history slot. Confidence: High Uncertainty: The amounts are inherited from the active fork, while their exact ordering is handled separately under state-access ordering and under-specification.
State-access ordering within opcode executionUnder-specified	1	The state-access and gas-charge path changes for the one BLOCKHASH opcode, which matches the single-opcode anchor.	eip.md · § Specification, resolve_blockhash pseudocode and following SLOAD-effects list A single existing opcode now conditionally performs an SLOAD-like access, charge, warm-up, and state-access record after its window checks. eip.md · § Test Cases bullets 1-4 Out-of-window calls have no storage effects, while in-window calls distinguish cold and warm slots and retain the BLOCKHASH charge. Confidence: Medium Uncertainty: The text does not explicitly order the original BLOCKHASH charge, the SLOAD charge, access recording, and warming at every insufficient-gas boundary.
Patterns affecting pre-existing tests	1	A minor, opcode-specific subset of existing tests must be updated for gas and access effects; the change does not rework diverse transaction or block categories.	eip.md · § Backwards Compatibility; § Test Cases bullets 1-4 Existing in-window BLOCKHASH use receives a significant gas increase and new cold/warm and state-access effects, but return-value semantics stay unchanged. Confidence: Medium Uncertainty: The package does not enumerate the pre-existing test corpus.
New invariant on pre-existing tests	1	A narrow category of otherwise pre-existing BLOCKHASH tests gains additional access-state assertions, rather than every test in the fork gaining an invariant.	eip.md · § Specification, SLOAD-effects list; § Test Cases bullets 1-3 Tests executing an in-window BLOCKHASH must additionally observe the matching slot's warming and any active-fork state-access recording. Confidence: Medium Uncertainty: Which test formats expose active-fork access records is not specified.

Show 17 zero-score criteria

Zero-score criteria (Checklist revision 2)
Criterion	Why this score	Evidence / uncertainty
Added opcodes	No opcode is added.	eip.md · § Abstract; § Specification The proposal updates the existing BLOCKHASH opcode at byte 0x40. Uncertainty: None.
Added precompiles	No precompile is added.	eip.md · § Abstract; § Specification The scope is an opcode and an existing system-contract storage slot, not a precompile. Uncertainty: None.
Modified precompiles	No pre-existing precompile is modified.	eip.md · § Abstract; § Specification No precompile logic or gas schedule is mentioned or changed. Uncertainty: None.
Added system contracts	No new system contract is added by this proposal.	eip.md · Front matter requires field; § Specification; § Activation EIP-7709 assumes and reads the EIP-2935 history contract rather than introducing one. supporting/eip-2935.md · § Specification > Block hash history contract; § Deployment The stateful history contract and its deployment are defined by EIP-2935. Uncertainty: Dependency on an existing system contract is scored under cross-EIP interactions.
Blob gas accounting changes	No blob gas accounting changes are introduced.	eip.md · § Abstract; § Specification > Gas costs The only added charge is an execution-gas SLOAD charge for BLOCKHASH; no blob gas rule is specified. Uncertainty: The package contains no blob-gas surface.
State gas accounting changes	No state-writing gas rate, charging site, budget, reservoir, or spill rule changes.	eip.md · § Specification, SLOAD-effects list; § Gas costs The proposal applies a storage read and its execution-gas effects, not a state write or state-gas charge. Uncertainty: Slot warming is an access effect and is not a state-gas write charge.
New EVM gas refund	No EVM gas-refund mechanism is added or changed.	eip.md · § Specification > Gas costs; § Test Cases The specified gas effects are charges only; no refund is introduced. Uncertainty: No refund behavior appears in the sealed proposal.
New transaction types	No new transaction type is introduced.	eip.md · § Abstract; § Specification No transaction envelope or transaction type is introduced. Uncertainty: None.
New or modified transaction validity mechanisms	The change affects runtime opcode execution only, not transaction validity mechanisms.	eip.md · § Specification > Gas costs; § Backwards Compatibility Execution may consume more gas and break gas-sensitive use cases, but no transaction validity rule or intrinsic-gas calculation is changed. Uncertainty: Runtime out-of-gas behavior is distinct from intrinsic validity under this anchor.
New block / header fields	No new block or header field is introduced.	eip.md · § Specification Existing block number, timestamp, and hash information is consumed; no field is added. Uncertainty: None.
Encoding changes (RLP/SSZ)	No RLP, SSZ, or other transaction/block/interface encoding change is introduced.	eip.md · § Specification The proposal changes opcode resolution and state effects without transaction, block, or interface encoding. Uncertainty: The modulo slot mapping is not an interface encoding change.
Block syncing changes	No block-RLP validation or sync mechanism is introduced.	eip.md · § Specification The change is opcode execution against state and introduces no block RLP validation rule. Uncertainty: The proposal's history prerequisite does not itself modify block encoding validation.
New fork activation mechanism	This is an ordinary rule switch, not a fork-block state mutation mechanism.	eip.md · § Specification, fork_block definition; § Activation Opcode logic switches at the timestamp and assumes EIP-2935 history is already available; no one-time state or internal-variable modification is prescribed at activation. Uncertainty: The timestamp and deployment spacing remain TBD, but the EIP prescribes no activation-block mutation.
Engine API changes	The proposal has no Engine API surface.	eip.md · § Abstract; § Specification No Engine API field, endpoint, or communication mechanism is specified. Uncertainty: None within the sealed package.
Transition-tool interface changes	No transition-tool interface modification is required by the text.	eip.md · § Specification parameter table; § Activation The proposal supplies a normal fork timestamp parameter and execution rule but defines no transition-tool field or interface mechanism. Uncertainty: FORK_TIMESTAMP is TBD, but that is a parameter gap rather than a new interface field.
New test-framework primitives	Existing EVM gas, storage-access, and fork test primitives appear sufficient.	eip.md · § Test Cases The listed cases use ordinary opcode result, gas, repeated-access, and direct-call observations. Uncertainty: No test-framework inventory is part of the package, so this rests on the specified case shapes.
Cryptography	No new or modified cryptography mechanism is specified.	eip.md · § Abstract; § Specification The mechanism reads an already-stored block hash by slot and introduces no cryptographic operation. Uncertainty: Block hashes are data being retrieved, not a new cryptographic mechanism here.

Assessment provenance

Assessed EIP revision: ethereum/EIPs@ac450a4ab2 EIPS/eip-7709.md committed 2026-08-25 · information cutoff 2026-08-25T11:56:58Z
Current master · File history · blob 0c7c4c625e · sha256 ed806dda2e43
Rubric: Checklist revision 2 · ethspecs/pm@3d8c0128c5
Evaluator: gpt-5.6-sol at xhigh reasoning effort · isolation bubblewrap_one_eip_capsule_v1
Source record: Frozen research record research/tasks/08-hegota-prospective-complexity-assessment/outputs/assessments/hegota-pfi-2026-08-26/eip-7709.yaml · sha256 a0e76be8f159
Supporting documents in the sealed package: supporting/eip-2935.md

Evaluated on: Not recorded

17MediumMedium

Evaluator: HumanChecklist v2
Confidence: Not recorded
Under-specified at assessment cutoff: Not recorded in the checklist
Checklist published: 2026-08-24
Source: open ethspecs/pm pull request #120

Score bands · Checklist revision 2

Low <12
Medium 12–22
High ≥23

28 criteria scored 0–3 (4 in exceptional cases; cross-EIP interactions is uncapped); nominal maximum 84.

Complexity profile

Each segment is one criterion's contribution to the Human total. Hover or focus a segment for its score and rationale.

Top complexity drivers

State-access ordering within opcode execution2
Patterns affecting pre-existing tests2
Edge/boundary conditions2
Cross-EIP interactions2

Criterion breakdown

EIP-7709 Hegotá: Human criterion scores and rationale
Criterion	Score	Why this score	Notes
State-access ordering within opcode execution	2	Only `BLOCKHASH` being impacted and now accounting for state access cost.	—
Patterns affecting pre-existing tests	2	Most of the `BLOCKHASH` related tests need refactoring, but impact is limited (27 places under tests/ folder, excluding `tests/benchmark`)	—
Edge/boundary conditions	2	Multiple interacting edge cases: (1) window boundary (`arg == block.number`, `> block.number`, `== 2**256-1`, `-1`, `-256 vs -257`), (2) young chain (`block.number < 256`, cold charge on unwritten slots), (3) modulus mismatch (`8191` vs `256`, `EIP-2935` slot warming), (4) cold/warm state (`EIP-2930` access lists, `SLOAD` collisions), (5) revert rollback and OOG at cold-charge boundary, (6) fork-transition window.	—
Cross-EIP interactions	2	4 interacting EIPs: EIP-2935 (hard dependency, ring-buffer state), EIP-2929 (cold/warm foundation), EIP-2930 (access list pre-warming), EIP-7928 (BAL recording). Test vectors need redesign.	—
Unspecified behavior requiring cross-client consensus	2	(1) does the lookup add HISTORY_STORAGE_ADDRESS to accessed_addresses? (2) whether the account appears in the BAL account list when only a slot is read through the opcode, and whether the access is recorded when the opcode OOGs on the cold charge.	—
Modified opcodes	1	BLOCKHASH now has state-access side effects: slot warming and state-access records, observable independently of gas. At activation, in-window lookups return 0 if < 256 blocks since EIP-2935 fork (vs pre-fork real hash).	—
Modified system contracts	1	The history contract's code and state are not directly modified, but there's an indirect effect: `BLOCKHASH` warms the contract's storage slot, making subsequent `SLOAD` calls within `get()` warm. Conversely, `SLOAD` on that slot warms it for `BLOCKHASH`.	—
EVM Gas rule changes	1	`BLOCKHASH` opcode gas costs now follow state access rules, accounting for cold/warm scenarios. This affects existing `BLOCKHASH` test cases but not other pre-existing scenarios. Given 1 point consider the impact should be limited.	—
New invariant on pre-existing tests	1	Pre-existing tests that call `BLOCKHASH` for an in-window ancestor must now assert a storage-read entry for `HISTORY_STORAGE_ADDRESS` in the BAL and the post-call warmth of that slot—even though these tests aren't about access lists. This narrowly affects only tests that already touch `BLOCKHASH`	—
New test-framework primitives	1	Add storage-access tracking to `BLOCKHASH`. Follow `Op.SLOAD(key_warm=...)` and integrate into fork gas map.	—
Security risks	1	106x cost increase might break `BLOCKHASH` callers. Interacts with EIP-2929/BAL. "MAY" clause risks consensus divergence if warming/recording skipped. Needs targeted review and fuzz testing on state-access accounting.	—
Performance risks	1	The new work reduces to an `SLOAD`, which is already benchmarked and already priced; the EIP strictly raises the cost of the operation, so worst-case throughput moves in the safe direction.	—

Show 16 zero-score criteria

Zero-score criteria (Checklist revision 2)
Criterion	Why this score	Notes
Added opcodes	No opcode added	—
Added precompiles	No added precompile	—
Modified precompiles	No modified precompile	—
Added system contracts	No system contracts added	—
Blob gas accounting changes	No blob gas accounting changes.	—
State gas accounting changes	No state gas accounting changes.	—
New EVM gas refund	No new gas-refund mechanisms are introduced.	—
New transaction types	No transaction types added	—
New or modified transaction validity mechanisms	No changes to transaction validity mechanisms	—
New block / header fields	No new block or header fields are introduced.	—
Encoding changes (RLP/SSZ)	No encoding rules changes	—
Block syncing changes	No block syncing changes	—
New fork activation mechanism	No state modifications, internal variables or similar are modified at the fork activation block.	—
Engine API changes	No engine API changes	—
Transition-tool interface changes	No interface changes	—
Cryptography	No cryptography mechanism added	—

Assessment provenance

Rubric: Checklist revision 2 · ethspecs/pm@3d8c0128c5
Evaluator: STEEL team · ethspecs/pm complexity_assessments
Source record: Open pull request #120: Add EIP-7709 complexity assessment · checklist at e75fc8b75e · updated 2026-08-24
blob f9b1c0170d · sha256 5a2a2b3c9308
Research record: research/tasks/09-hegota-human-assessment-snapshot/outputs/assessments/eip-7709.yaml · sha256 3feafcaf1e70

Both assessments applied Checklist revision 2 (28 criteria) to EIP-7709 in Hegotá. Δ is LLM minus Human.

Using the latest scored LLM evaluation for this checklist: 2026-08-26 · spec 2026-08-25 · ac450a4ab2. The Human and LLM assessments may use different spec revisions.

LLM20Medium

Human17Medium

Δ total+3Same tier

Criteria20/28agree exactly · 7 differ by 1 · 1 differ by 2+

Complexity profiles side by side

LLM

Human

Largest disagreements: Modified opcodes (+2), State-access ordering within opcode execution (−1), Patterns affecting pre-existing tests (−1), New test-framework primitives (−1), Edge/boundary conditions (+1)

Show differences only (8 criteria)

Per-criterion scores, Human versus LLM, ordered by the size of the difference
Criterion	LLM	Human	Δ	Agreement	Rationale from each source
Modified opcodes	3	1	+2	Differ by 2+	Show rationale LLM Although its returned value is preserved, at least one pre-existing opcode's observable behavior beyond gas is modified, invoking the rubric's binary score of 3. Human BLOCKHASH now has state-access side effects: slot warming and state-access records, observable independently of gas. At activation, in-window lookups return 0 if < 256 blocks since EIP-2935 fork (vs pre-fork real hash).
State-access ordering within opcode execution	1	2	−1	Differ by 1	Show rationale LLM The state-access and gas-charge path changes for the one BLOCKHASH opcode, which matches the single-opcode anchor. Human Only `BLOCKHASH` being impacted and now accounting for state access cost.
Patterns affecting pre-existing tests	1	2	−1	Differ by 1	Show rationale LLM A minor, opcode-specific subset of existing tests must be updated for gas and access effects; the change does not rework diverse transaction or block categories. Human Most of the `BLOCKHASH` related tests need refactoring, but impact is limited (27 places under tests/ folder, excluding `tests/benchmark`)
New test-framework primitives	0	1	−1	Differ by 1	Show rationale LLM Existing EVM gas, storage-access, and fork test primitives appear sufficient. Human Add storage-access tracking to `BLOCKHASH`. Follow `Op.SLOAD(key_warm=...)` and integrate into fork gas map.
Security risks	2	1	+1	Differ by 1	Show rationale LLM The mechanism touches a limited set of existing consensus-critical components and slightly alters resource and access-state assumptions, warranting targeted review and fuzzing. Human 106x cost increase might break `BLOCKHASH` callers. Interacts with EIP-2929/BAL. "MAY" clause risks consensus divergence if warming/recording skipped. Needs targeted review and fuzz testing on state-access accounting.
Performance risks	2	1	+1	Differ by 1	Show rationale LLM The cost can be microbenchmarked, but end-to-end effects depend on state/cache and access-recording behavior; impact is limited to in-window BLOCKHASH execution. Human The new work reduces to an `SLOAD`, which is already benchmarked and already priced; the EIP strictly raises the cost of the operation, so worst-case throughput moves in the safe direction.
Edge/boundary conditions	3	2	+1	Differ by 1	Show rationale LLM Multiple boundary-prone mechanisms interact, and the in/out-of-window boundary requires an elevated matrix across gas sufficiency, cold/warm status, repeated access, access recording, and activation history. Human Multiple interacting edge cases: (1) window boundary (`arg == block.number`, `> block.number`, `== 2**256-1`, `-1`, `-256 vs -257`), (2) young chain (`block.number < 256`, cold charge on unwritten slots), (3) modulus mismatch (`8191` vs `256`, `EIP-2935` slot warming), (4) cold/warm state (`EIP-2930` access lists, `SLOAD` collisions), (5) revert rollback and OOG at cold-charge boundary, (6) fork-transition window.
Unspecified behavior requiring cross-client consensus	3	2	+1	Differ by 1	Show rationale LLM A previously non-state-accessing opcode gains consensus-observable access records and warming. The unspecified charge/access sequence can produce different observable results at gas boundaries and therefore requires cross-client agreement and re-baselining. Human (1) does the lookup add HISTORY_STORAGE_ADDRESS to accessed_addresses? (2) whether the account appears in the BAL account list when only a slot is read through the opcode, and whether the access is recorded when the opcode OOGs on the cold charge.
Added opcodes	0	0	0	Agree	Show rationale LLM No opcode is added. Human No opcode added
Added precompiles	0	0	0	Agree	Show rationale LLM No precompile is added. Human No added precompile
Modified precompiles	0	0	0	Agree	Show rationale LLM No pre-existing precompile is modified. Human No modified precompile
Added system contracts	0	0	0	Agree	Show rationale LLM No new system contract is added by this proposal. Human No system contracts added
Modified system contracts	1	1	0	Agree	Show rationale LLM The pre-existing history contract has a minor indirect gas-context effect: a prior BLOCKHASH can warm its storage slot for later access, without code or state modification. Human The history contract's code and state are not directly modified, but there's an indirect effect: `BLOCKHASH` warms the contract's storage slot, making subsequent `SLOAD` calls within `get()` warm. Conversely, `SLOAD` on that slot warms it for `BLOCKHASH`.
EVM Gas rule changes	1	1	0	Agree	Show rationale LLM The gas accounting of an existing opcode is updated by composing it with the existing SLOAD schedule; no separate new gas-accounting mechanism is defined. Human `BLOCKHASH` opcode gas costs now follow state access rules, accounting for cold/warm scenarios. This affects existing `BLOCKHASH` test cases but not other pre-existing scenarios. Given 1 point consider the impact should be limited.
Blob gas accounting changes	0	0	0	Agree	Show rationale LLM No blob gas accounting changes are introduced. Human No blob gas accounting changes.
State gas accounting changes	0	0	0	Agree	Show rationale LLM No state-writing gas rate, charging site, budget, reservoir, or spill rule changes. Human No state gas accounting changes.
New EVM gas refund	0	0	0	Agree	Show rationale LLM No EVM gas-refund mechanism is added or changed. Human No new gas-refund mechanisms are introduced.
New transaction types	0	0	0	Agree	Show rationale LLM No new transaction type is introduced. Human No transaction types added
New or modified transaction validity mechanisms	0	0	0	Agree	Show rationale LLM The change affects runtime opcode execution only, not transaction validity mechanisms. Human No changes to transaction validity mechanisms
New block / header fields	0	0	0	Agree	Show rationale LLM No new block or header field is introduced. Human No new block or header fields are introduced.
Encoding changes (RLP/SSZ)	0	0	0	Agree	Show rationale LLM No RLP, SSZ, or other transaction/block/interface encoding change is introduced. Human No encoding rules changes
Block syncing changes	0	0	0	Agree	Show rationale LLM No block-RLP validation or sync mechanism is introduced. Human No block syncing changes
New fork activation mechanism	0	0	0	Agree	Show rationale LLM This is an ordinary rule switch, not a fork-block state mutation mechanism. Human No state modifications, internal variables or similar are modified at the fork activation block.
Engine API changes	0	0	0	Agree	Show rationale LLM The proposal has no Engine API surface. Human No engine API changes
Transition-tool interface changes	0	0	0	Agree	Show rationale LLM No transition-tool interface modification is required by the text. Human No interface changes
New invariant on pre-existing tests	1	1	0	Agree	Show rationale LLM A narrow category of otherwise pre-existing BLOCKHASH tests gains additional access-state assertions, rather than every test in the fork gaining an invariant. Human Pre-existing tests that call `BLOCKHASH` for an in-window ancestor must now assert a storage-read entry for `HISTORY_STORAGE_ADDRESS` in the BAL and the post-call warmth of that slot—even though these tests aren't about access lists. This narrowly affects only tests that already touch `BLOCKHASH`
Cryptography	0	0	0	Agree	Show rationale LLM No new or modified cryptography mechanism is specified. Human No cryptography mechanism added
Cross-EIP interactions	2	2	0	Agree	Show rationale LLM Coordinated testing is required with EIP-2935 and its EIP-2929 cold/warm behavior, plus whatever active-fork access-recording rule applies; the dependency is strong but localized. Human 4 interacting EIPs: EIP-2935 (hard dependency, ring-buffer state), EIP-2929 (cold/warm foundation), EIP-2930 (access list pre-warming), EIP-7928 (BAL recording). Test vectors need redesign.

Compare EIP-7709 with other assessments All Hegotá assessments

Criterion legend and glossary

Every stacked bar, comparison matrix, and criterion table on this site uses the same criterion colours, abbreviations, and order. Colour marks the criterion group; the abbreviation and name identify the criterion. Scores are 0–3 per criterion (4 is exceptional; cross-EIP interactions is uncapped).

EVM surface

Opcodes, precompiles, and system contracts that are added or modified.

OP+
Added opcodes
Introduces new opcodes
Score anchors
0
No new opcodes are introduced.
1
A new simple opcode is introduced (no data portion, no complex stack mechanics, and a constant gas cost).
2
Multiple new simple opcodes are introduced, or a single new complex opcode is introduced (has data portion, or complex stack mechanics, or a dynamic gas cost).
3
Multiple new opcodes are introduced, and at least one of them is complex (has data portion, or complex stack mechanics, or a dynamic gas cost).
- Cryptography opcodes are not considered complex by default. Refer to the "Cryptography" section for a separate assessment.
Modified opcodes
Modifies pre-existing opcodes
Score anchors
0
No pre-existing opcode modifications are introduced.
3
At least one pre-existing opcode's behavior is modified (not including gas changes) or a pre-existing opcode is deprecated.
PC+
Added precompiles
Introduces new precompiles
Score anchors
0
No new precompiles are introduced.
1
A new simple precompile is introduced (constant input length, constant gas cost).
2
Multiple new simple precompiles are introduced, or a single new complex precompile is introduced (dynamic input length or dynamic gas cost).
3
Multiple new precompiles are introduced, and at least one of them is complex (dynamic input length or dynamic gas cost).
- Cryptography precompiles are not considered complex by default. Refer to the "Cryptography" for a separate assessment.
Modified precompiles
Modifies pre-existing precompiles logic or gas-accounting
Score anchors
0
No pre-existing precompiles are modified.
1
At least one pre-existing precompile has its gas schedule modified.
2
Multiple pre-existing precompiles have their gas schedule modified, or a single pre-existing precompile has its behavior modified.
3
The behavior of multiple pre-existing precompiles, or a single complex pre-existing precompile modified.
Added system contracts
Introduces new system contract, stateful or not
Score anchors
0
No new system contracts are introduced.
1
A new system contract is introduced that is not stateful nor does it trigger a new system action (e.g. requests to the consensus layer).
2
Multiple new system contracts are introduced or a single new system contract that is either stateful or triggers a new system action (e.g. requests to the consensus layer).
3
Multiple new system contracts are introduced and at least one of them is either stateful or triggers a new system action (e.g. requests to the consensus layer).
Modified system contracts
Modifies pre-existing system contracts
Score anchors
0
No modifications to pre-existing system contracts are introduced, directly or indirectly.
1
Does not directly modify any system contract, but its behavior has minor indirect effects on one or more system contracts.
2
Does not directly modify any system contract, but its behavior has major indirect effects on one or more system contracts.
3
At least one pre-existing system contract code or state is modified, which would involve irregular state transition or a similarly complex transition methodology.

Gas and accounting

Execution, blob, and state gas rules, refunds, and where charges happen inside opcodes.

EVM Gas rule changes
New EVM gas accounting rules
Score anchors
0
No gas accounting changes.
1
Existing gas accounting mechanism is updated.
2
A new gas accounting mechanism is introduced but it does not affect existing mechanisms nor does it affect existing tests.
3
A new gas accounting mechanism is introduced and affects existing mechanisms which in turn affect existing tests.
ORD
State-access ordering within opcode execution · Checklist revision 2 only
Changes *where inside an opcode's execution* state is accessed, or where gas is charged relative to that access. Because a state access is recorded in the block-level access list only if execution had enough gas to reach it, this ordering is consensus-critical: moving it changes the BAL at every gas boundary of every affected opcode.
Score anchors
0
No change to where state is accessed, or to where gas is charged relative to a state access, within any opcode.
1
A single opcode's state-access or gas-charge ordering changes.
2
Multiple opcodes' ordering changes, or a new state-accessing operation is introduced whose position in the order must be settled.
3
The ordering rule changes for a whole class of state-accessing opcodes at once, or what counts as a recordable state access is redefined — requiring existing BAL vectors to be re-derived across opcodes and forks.
- Distinct from "Modified opcodes", which asks whether an opcode's **result** changed. This row asks about the **path to the result**, which is observable even when the result is identical. An EIP can be 0 on that row and 3 on this one.
- Score changes **to** the ordering. Do not score the fact that state accesses are observable — they always are.
- Each boundary must be re-tested against every other dimension that can change the answer (cold/warm, static/non-static, delegated/direct, revert/success), so the case count grows multiplicatively rather than additively. Note this explicitly under Special Considerations.
Blob gas accounting changes
New Blob gas accounting rules which potentially affect pre-existing tests
Score anchors
0
No blob gas accounting changes.
1
Existing blob gas accounting mechanism is updated.
2
A new blob gas accounting mechanism is introduced but it does not affect existing mechanisms nor does it affect existing tests.
3
A new blob gas accounting mechanism is introduced and affects existing mechanisms which in turn affect existing tests.
SGAS
State gas accounting changes · Checklist revision 2 only
New state gas accounting rules. State gas is the cost of *writing* state, as opposed to accessing or executing it: `StateGasCosts`, `COST_PER_STATE_BYTE`, the block-level state gas budget, and the spill path into execution gas.
Score anchors
0
No state gas accounting changes.
1
An existing state gas cost or `STATE_BYTES_PER_*` rate is adjusted.
2
A new state-gas-charging site is introduced, or the block-level state gas budget or reservoir allocation is modified.
3
A new state gas charging mechanism is introduced, or the spill interaction between state gas and execution gas is modified, affecting existing gas tests.
- Harder to test than blob gas: the spill path means state gas cannot be metered independently of execution gas, and some costs (e.g. `NEW_ACCOUNT`) are state-dependent.
New EVM gas refund
New gas-refund mechanism
Score anchors
0
No new gas-refund mechanisms are introduced.
1
A new simple gas-refund mechanism is introduced that does not affect either existing tests or existing gas-refund mechanisms.
2
A new complex gas-refund mechanism is introduced or a simple mechanism that affects existing tests or existing gas-refund mechanisms.
3
A new complex gas-refund mechanism is introduced that affects existing tests or existing gas-refund mechanisms.

Blocks, transactions, and encoding

Transaction types and validity, block and header fields, encodings, syncing, and activation-time changes.

New transaction types
Introduces a new transaction type
Score anchors
0
No new transaction types are introduced.
3
A new transaction type is introduced.
New or modified transaction validity mechanisms
Creates new or modifies pre-existing transaction types' validation mechanisms
Score anchors
0
No changes are introduced to the validity rules of existing transaction types or to their intrinsic gas cost calculation.
1
Minor adjustments are introduced to validity rules or intrinsic gas cost calculation, but they do not significantly affect existing tests.
2
Changes to validity rules or intrinsic gas cost calculation affect existing tests, but require only limited updates to test cases and no redesign of the testing infrastructure.
3
Changes to validity rules or intrinsic gas cost calculation require extensive rework or redesign of the tests or testing infrastructure.
New block / header fields
Introduces new block or block header fields
Score anchors
0
No new block or header fields are introduced.
3
A new block or header field is introduced.
ENC
Encoding changes (RLP/SSZ)
Introduces encoding changes at the transaction/block/interfaces level
Score anchors
0
No encoding changes are introduced at the transaction, block, or interfaces levels.
3
An encoding change is introduced at transaction, block or interfaces level (e.g. RLP -> SSZ).
- "Interfaces level" includes the Engine API. Score an Engine API encoding change (e.g. JSON -> SSZ) here.
Block syncing changes
Modifies block RLP validation mechanisms that require test client syncing.
Score anchors
0
No new RLP validation mechanism is introduced.
1
A single simple RLP validation mechanism is introduced.
2
Multiple simple RLP validation mechanisms are introduced or a single complex one.
3
Multiple RLP validation mechanisms are introduced and at least one of them is deemed complex.
ACT
New fork activation mechanism
Modifies state, internal variables, or similar, at the fork activation block
Score anchors
0
No state modifications, internal variables or similar are modified at the fork activation block.
3
Either a state modification or internal variables are modified at the fork activation block.
- Initialization of new internal variable is not considered a modification.

Client interfaces

Engine API and transition-tool interface changes.

Engine API changes
Introduces new fields to the Engine API directives
Score anchors
0
No new fields or communication mechanisms are introduced to the Engine API.
1
A single new field is introduced in one of the Engine API endpoints.
2
Multiple fields are introduced to one or multiple Engine API end points, or a new Engine API end-point is introduced.
3
Multiple fields are introduced to one or multiple Engine API end points and a new Engine API end-point is introduced.
Engine API encoding changes · Checklist revision 1 only
Engine API encoding changes (the revision-1 template defines no anchor text for this row).
T8N
Transition-tool interface changes
Modifies or adds new fields to the transition tool interface.
Score anchors
0
No modifications to the transition tool interface are required.
1
A single new field needs to be introduced to the transition tool interface.
2
Multiple new fields or a new mechanism has to be introduced to the transition tool interface.
3
Multiple new fields and a new mechanism has to be introduced to the transition tool interface.
- Special consideration must be paid to this section if the EIP introduces a mechanism that requires the state transition tool to be aware whether the block it is processing is the fork-activation block.

Testing impact

Rework, new invariants, and new primitives required in the test framework.

Patterns affecting pre-existing tests
Implements a new validation mechanism or rule that translates in reworking pre-existing tests
Score anchors
0
No pre-existing tests are affected by this change.
1
Minor subset of existing tests are affected by this change.
2
Considerable subset of existing tests are affected by this change but involves only a contrived category of tests.
3
Major subset of existing tests are affected, including diverse category of tests (benchmarks, static, multiple forks, etc.).
INV
New invariant on pre-existing tests · Checklist revision 2 only
Tests that are **not about this EIP** must nonetheless assert something this EIP produces. Their logic does not change; they gain a new thing to check.
Score anchors
0
Pre-existing tests assert nothing new.
1
A narrow, contrived category of pre-existing tests gains a new assertion.
2
A broad category gains a new assertion, applied mechanically.
3
Every test in the fork gains the assertion regardless of what it tests, and pre-fork vectors must be re-derived to satisfy it.
- Paired with the row above, and easy to confuse with it. "Patterns affecting pre-existing tests" asks whether existing tests must be **reworked**; this row asks whether they must **additionally assert something new**. Score both — an EIP can be low on one and high on the other.
New test-framework primitives · Checklist revision 2 only
Requires new abstractions in the test framework itself — expectation types, modifiers, helpers — beyond writing test functions with what already exists.
Score anchors
0
Existing test primitives suffice.
1
Existing primitives need minor extension.
2
New expectation or modifier primitives are required, reusable within this EIP's own test suite.
3
New framework-level primitives are required that become a permanent part of the framework and are used by other EIPs' tests.

Risk and validation

Security, performance, boundary conditions, and cryptography that need validation.

Security risks
Introduces or modifies mechanisms that could compromise the security of the chain, users, validators, or other stakeholders, if not implemented properly.
Score anchors
0
No new mechanisms are introduced that could pose a security risk.
1
The introduced mechanisms are self-contained, can be validated in isolation, and do not alter existing invariants that could pose a security risk for any stakeholders.
2
The introduced mechanisms interact with a limited number of existing components, slightly altering their security assumptions and requiring a targeted security review or fuzzing.
3
The introduced mechanisms interact with multiple existing components, including critical ones, substantially altering their security assumptions and requiring an extensive security review and fuzzing.
Performance risks
Introduces or modifies mechanisms and requires performance validation.
Score anchors
0
No new mechanisms are introduced that require performance validation.
1
The introduced mechanisms can be benchmarked in isolation and do not affect existing performance behavior.
2
The introduced mechanisms cannot be fully benchmarked in isolation, but they only have a limited impact on the existing performance benchmarks.
3
The introduced mechanisms cannot be benchmarked in isolation and have a substantial impact on existing performance benchmarks or have complex interactions with existing mechanisms.
Edge/boundary conditions
Feature contains edge/boundary conditions.
Score anchors
0
No discernible edge cases or boundary conditions are introduced.
1
A single edge-case or boundary-condition prone mechanism is introduced.
2
Multiple edge-case or boundary-condition prone mechanisms are introduced, but none of them requires an elevated number of cases to test.
3
Multiple edge-case or boundary-condition prone mechanisms are introduced and at least one of them requires an elevated number of cases to test.
Cryptography
Introduces new cryptography mechanisms or modifies existing functionality that involves cryptography
Score anchors
0
No cryptography mechanisms are introduced.
1
A new cryptography mechanism is introduced but it is a well known mechanism that is known to have vast resources to aid on its testing.
2
Multiple new cryptography mechanisms are introduced that are well-known or a single but novel mechanism is introduced that is either untested or has limited resources.
3
Multiple new cryptography mechanisms are introduced and at least one of them is a novel mechanism.

Coordination

Cross-EIP interactions and behavior that clients must agree on before tests exist.

XEIP
Cross-EIP interactions
Introduces or modifies mechanisms that affect other EIPs in either the same or past forks.
Score anchors
0
Fully self-contained EIP that does not depend on, modify, or conflict with any other EIP.
1
The EIP interacts with one or more other EIPs in a non-critical and limited way but can be tested independently for the most part.
2
The EIP depends on or modifies one or more other EIPs such that coordinated testing and consideration is required, but interactions are limited in scope and not complex.
3
The EIP has strong interdependencies with multiple EIPs, requiring extensive coordinated cross-EIP testing as well as potential re-design of existing test vectors.
- +1 for every 3 additional interacting EIPs beyond the first 3, each of which requires its own coordinated test cases. List the EIPs in the rationale.
- This row is intentionally uncapped, unlike every other anchor: each interacting EIP is another axis of the test matrix, so a ceiling would make a 12-EIP product indistinguishable from a 3-EIP one.
UNSP
Unspecified behavior requiring cross-client consensus · Checklist revision 2 only
The EIP text does not determine the answer for cases a test can construct. Clients must agree on a previously unspecified detail before tests can be baselined. The cost here is coordination and re-baselining, not test writing.
Score anchors
0
The EIP text determines the answer for every case a test could construct.
1
A few details are unspecified but have an obvious intended reading.
2
Details require client agreement before tests can be written, but they are localized.
3
A previously unspecified *and previously unobservable* behavior becomes consensus-critical; expect tests to be re-baselined on each round of EIP amendment.
- Score this from the EIP's state at assessment time: whether it has client implementations, whether it has been through a devnet, and how many open questions remain on its discussion thread.