EIP complexity assessment

EIP-7668: Remove bloom filters

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 10

Human Available in open PRscore 7 · Checklist revision 2· ethspecs/pm #118

Other checklist versions (2)

Merged file · Checklist revision 1 · total 2
Pull request #122 (draft) · Checklist revision 1 · total 2 · same scores as the shown checklist

LLM · Checklist revision 22026-08-26 · Original snapshot · 10 Human · Checklist revision 2Available in open PR · 7 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 sealed EIP-7668 snapshot: the proposal requires the existing logs-bloom values in every execution block and transaction receipt to be zero bytes long while retaining the fields and leaving LOG gas costs unchanged.

10LowLow

Evaluator: LLMChecklist v2
Confidence: Medium
Under-specified at assessment cutoff: Yes — 2 criteria affected
Plausible range: 8–12 (Low–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.

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 proposal supplies no testing section or inventory of existing execution tests. Its universal block/receipt rule establishes broad structural impact, but the package does not quantify how many pre-existing test categories must be reworked or which tests expose these fields as added assertions.

Plausible total

8–12
recorded score 10 · plausible tiers Low, Medium

Affected criteria (2)

Patterns affecting pre-existing tests (2)
New invariant on pre-existing tests (2)

Unresolved questions at the cutoff (2)

How broadly do existing execution-test categories construct or assert block-level and receipt-level logs-bloom encodings?
Does every test in the target fork expose these fields to an additional invariant, and do any pre-fork vectors require re-derivation?

Notable ambiguities noted by the assessor (1)

The EIP mandates zero-byte values but does not name the serialization codec or describe block-sync validation workflows; the assessment treats the two object-level length requirements as two simple encoded-field validation changes.

Criterion breakdown

EIP-7668 Hegotá: LLM criterion scores and rationale
Criterion	Score	Why this score	Evidence / uncertainty
Encoding changes (RLP/SSZ)	3	This is an encoding-level change at the block and receipt interfaces: retained fields must carry a zero-length byte value. The rubric assigns 3 whenever a transaction, block, or interface encoding change is introduced.	eip.md · Specification The existing logs-bloom values in the execution block and transaction receipt are newly required to encode as zero bytes long. eip.md · Rationale, paragraph 1 The fields are retained for now rather than removed entirely. Confidence: High Uncertainty: The EIP does not name the serialization codec, but it explicitly changes the byte length of fields in encoded execution objects.
Block syncing changes	2	Block/receipt ingestion gains two simple encoded-field validation rules, one at the block level and one at the receipt level, matching the multiple-simple-mechanism anchor.	eip.md · Specification A synced execution block's top-level logs bloom and each transaction receipt's logs bloom must each satisfy a new zero-byte-length rule. Confidence: Medium Uncertainty: The EIP does not name RLP or describe sync workflows; the score is grounded in the two explicit encoded execution-object validity conditions.
Patterns affecting pre-existing testsUnder-specified	2	Pre-existing vectors that construct or validate blocks or receipts with the former bloom representation require updates across two broad output surfaces. The update is structurally mechanical, and the package does not establish the diverse test-category impact required for score 3.	eip.md · Specification Both every execution block's logs bloom and every transaction receipt's logs bloom are newly required to be zero bytes long. eip.md · Backwards Compatibility Applications that depend on bloom filters to read events cease to work. Confidence: Medium Uncertainty: The EIP has no testing section or test inventory, so the exact breadth of pre-existing test rework is not quantified.
New invariant on pre-existing testsUnder-specified	2	A broad category of existing block and receipt tests gains a mechanical empty-value invariant even when the test is about another behavior. The package does not show that every fork test gains the assertion or that pre-fork vectors must be re-derived, so score 3 is not supported.	eip.md · Abstract Bloom filters in an execution block, at top level and in receipt objects, must be empty. eip.md · Specification The zero-length requirement is stated for execution-block and transaction-receipt logs blooms without limiting it to logging-focused cases. Confidence: Medium Uncertainty: The universal protocol wording supports broad mechanical coverage, but the sealed package does not describe how all test categories expose these outputs.
Edge/boundary conditions	1	The proposal introduces one simple boundary-prone rule—exactly zero bytes—applied at the block and receipt levels; tests must distinguish empty values from any non-empty representation.	eip.md · Specification Valid block and receipt bloom values are placed at the zero-length boundary. Confidence: High Uncertainty: The same simple length boundary is repeated at two sites, but the package identifies no additional interacting boundary mechanism.

Show 23 zero-score criteria

Zero-score criteria (Checklist revision 2)
Criterion	Why this score	Evidence / uncertainty
Added opcodes	No new opcode is introduced.	eip.md · Rationale, paragraph 2 The proposal discusses retaining the gas costs of existing LOG operations and introduces no opcode. Uncertainty: The only opcode reference concerns unchanged gas costs for existing LOG operations.
Modified opcodes	No existing opcode's behavior is modified or deprecated; bloom output handling changes outside the stated opcode behavior.	eip.md · Specification The specified behavior change is to block and receipt bloom fields, not to an opcode result. eip.md · Rationale, paragraph 2 LOG gas costs are explicitly left unchanged. Uncertainty: The sealed text does not define any LOG semantic change beyond explaining why its gas price stays unchanged.
Added precompiles	No precompile is introduced.	eip.md · Specification Only existing logs-bloom fields receive new empty-value requirements. Uncertainty: The sealed proposal contains no precompile mechanism.
Modified precompiles	No existing precompile logic or gas schedule is modified.	eip.md · Specification Only existing logs-bloom fields receive new empty-value requirements. Uncertainty: The sealed proposal contains no precompile provision.
Added system contracts	No system contract is introduced.	eip.md · Specification The normative change consists only of emptying two existing bloom fields. Uncertainty: The sealed proposal contains no contract deployment or system action.
Modified system contracts	No pre-existing system contract code, state, or behavior is directly or indirectly modified by a stated mechanism.	eip.md · Specification The normative change only affects execution-block and receipt bloom values. Uncertainty: No system contract is identified in the sealed proposal.
EVM Gas rule changes	No EVM gas-accounting rule is changed; the only opcode-related gas decision is to retain the existing LOG costs.	eip.md · Rationale, paragraph 2 The proposal explicitly says that gas costs of LOG are not reduced. Uncertainty: No material uncertainty: unchanged LOG gas costs are explicit, and no other gas rule is specified.
State-access ordering within opcode execution	The proposal does not move a state access or a gas charge within any opcode; it changes block and receipt output fields.	eip.md · Specification The normative requirements only make the execution-block and transaction-receipt logs blooms empty. Uncertainty: No opcode-internal state-access ordering change is stated in the sealed proposal.
Blob gas accounting changes	No blob gas rule or mechanism is introduced or modified.	eip.md · Specification The normative change is limited to logs-bloom values in execution blocks and receipts. Uncertainty: The sealed proposal contains no blob-gas provision.
State gas accounting changes	No state-writing gas cost, state-gas charging site, budget, reservoir, or spill rule is changed.	eip.md · Specification The normative change only requires empty logs blooms at block and receipt level. Uncertainty: The sealed proposal contains no state-gas provision.
New EVM gas refund	The proposal introduces no gas-refund mechanism.	eip.md · Rationale, paragraph 2 LOG gas costs remain unchanged while bloom handling is removed. Uncertainty: No refund behavior is specified anywhere in the sealed proposal.
New transaction types	No new transaction type is introduced.	eip.md · Specification The proposal applies to receipt bloom values and introduces no transaction type. Uncertainty: The sealed proposal contains no transaction envelope or type addition.
New or modified transaction validity mechanisms	No existing transaction type's validity rules or intrinsic gas calculation are changed.	eip.md · Specification The new conditions apply to execution blocks and transaction receipts, not to transaction validity or intrinsic gas. Uncertainty: Receipt-output validity is separate from the transaction-validity mechanism scored by this anchor.
New block / header fields	The value constraint on an existing field changes, but no new block or header field is introduced.	eip.md · Rationale, paragraph 1 The minimally disruptive design retains the existing bloom field; a future EIP may remove it entirely. Uncertainty: Field retention is explicit in the rationale.
New fork activation mechanism	No special state transition or internal-variable modification at the fork-activation block is introduced.	eip.md · Specification The proposal states an ongoing empty-bloom validity rule and specifies no activation-block state or internal-variable mutation. Uncertainty: Ordinary application of a new fork rule is not the activation mechanism scored by this anchor.
Engine API changes	No new Engine API field or endpoint is introduced.	eip.md · Specification The proposal changes existing block and receipt bloom values and specifies no Engine API endpoint, field, or communication mechanism. Uncertainty: No Engine API change appears in the sealed proposal.
Transition-tool interface changes	Existing field values change, but no transition-tool interface field or new interface mechanism is introduced.	eip.md · Rationale, paragraph 1 The proposal intentionally retains the bloom fields and leaves complete field removal to a future EIP. Uncertainty: The EIP does not discuss transition tools; the score follows the rubric's field/mechanism criterion and the explicit retention of existing fields.
New test-framework primitives	Testing an existing field for an empty byte value does not require a new expectation type, modifier, or helper on the evidence provided.	eip.md · Specification The required result is a direct zero-byte-length condition on two existing bloom fields. Uncertainty: No framework or testing design is supplied, but the specified assertion uses ordinary value and length checks.
Security risks	No new mechanism that changes stakeholder security assumptions is introduced.	eip.md · Security Considerations The EIP states that no new feature is introduced or made cheaper and therefore raises no security concerns. Uncertainty: The sealed proposal explicitly assesses the change as raising no security concern.
Performance risks	The proposal removes bloom-filter handling and introduces no new mechanism whose performance must be validated under this risk anchor.	eip.md · Motivation The proposal removes an impractical historical-query aid rather than adding a new execution mechanism. eip.md · Rationale, paragraph 1 The stated design goal is to remove the need for clients to handle blooms while retaining the fields. Uncertainty: The package provides no benchmarks, but it specifies removal of work rather than a new or more complex performance-sensitive mechanism.
Cryptography	No cryptographic mechanism is added or modified by the proposal.	eip.md · Motivation, paragraph 3 ZK-SNARK-based indexes are only an encouraged external application direction, not a protocol feature introduced by this EIP. eip.md · Specification The only normative rules require empty logs blooms. Uncertainty: The cryptographic indexing idea is non-normative and extra-protocol, so it does not create execution-layer cryptography testing here.
Cross-EIP interactions	No numbered EIP dependency, modification, or conflict is identified, and the mentioned optional future cleanup is not required for this proposal to operate or be tested.	eip.md · Rationale, paragraph 1 A possible future EIP could remove the retained fields, but this proposal neither depends on that future cleanup nor identifies an EIP number. eip.md · Specification The current proposal is self-contained as two empty-bloom requirements. Uncertainty: The prospective unnumbered cleanup is contextual sequencing, not a current coordinated-testing interaction.
Unspecified behavior requiring cross-client consensus	For constructible cases within the proposal's stated surface, clients have a determinate required byte length at both locations, and the proposal does not expose a formerly unobservable choice that needs coordination.	eip.md · Specification For both affected locations, the required value is expressly defined as empty, meaning zero bytes long. eip.md · Rationale, paragraph 2 The only nearby gas question is resolved explicitly by retaining LOG gas costs. Uncertainty: Implementation, devnet, and discussion evidence is absent from the sealed evidence set, but no unresolved normative case is visible in the provided text.

Assessment provenance

Assessed EIP revision: ethereum/EIPs@ac450a4ab2 EIPS/eip-7668.md committed 2026-08-25 · information cutoff 2026-08-25T11:56:58Z
Current master · File history · blob fbd998df26 · sha256 816047a55941
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-7668.yaml · sha256 94c2708c61ea

Evaluated on: Not recorded

7LowLow

Evaluator: HumanChecklist v2
Confidence: Not recorded
Under-specified at assessment cutoff: Not recorded in the checklist
Checklist published: 2026-08-18
Source: open ethspecs/pm pull request #118

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

New test-framework primitives2
New block / header fields1
Block syncing changes1
Patterns affecting pre-existing tests1

Criterion breakdown

EIP-7668 Hegotá: Human criterion scores and rationale
Criterion	Score	Why this score	Notes
New test-framework primitives	2	29 framework files under `packages/testing/src` touch the bloom: header and receipt types, blockchain builder, RPC/hive. Both types need a fork-conditional shape, 256 bytes before and zero-length after.	—
New block / header fields	1	No field is added, an existing one is emptied. Deliberate departure: this anchor is binary 0/3 and recognises only additions. Actual removal is deferred to a future EIP.	—
Block syncing changes	1	`fork.py` rejects `block_logs_bloom != block.header.bloom`; that becomes a zero-length requirement. Receipts need no separate check, since a wrong bloom already surfaces as a `receipt_root` mismatch.	—
Patterns affecting pre-existing tests	1	1 hand-written test file references bloom, 0 under `tests/ported_static/`. Every fixture regenerates since block hashes move, but the sources stay put.	—
Performance risks	1	`eth_getLogs` might be affected and requires further review.	—
Cross-EIP interactions	1	EIP-7745 and EIP-8304 both replace what blooms were for, so whether this EIP is redundant or complementary to them needs deciding. Testable independently.	—

Show 22 zero-score criteria

Zero-score criteria (Checklist revision 2)
Criterion	Why this score	Notes
Added opcodes	No rationale recorded.	Blank cell read as zero because the published total proves it.
Modified opcodes	No rationale recorded.	Blank cell read as zero because the published total proves it.
Added precompiles	No rationale recorded.	Blank cell read as zero because the published total proves it.
Modified precompiles	No rationale recorded.	Blank cell read as zero because the published total proves it.
Added system contracts	No rationale recorded.	Blank cell read as zero because the published total proves it.
Modified system contracts	No rationale recorded.	Blank cell read as zero because the published total proves it.
EVM Gas rule changes	No rationale recorded.	Blank cell read as zero because the published total proves it.
State-access ordering within opcode execution	No rationale recorded.	Blank cell read as zero because the published total proves it.
Blob gas accounting changes	No rationale recorded.	Blank cell read as zero because the published total proves it.
State gas accounting changes	No rationale recorded.	Blank cell read as zero because the published total proves it.
New EVM gas refund	No rationale recorded.	Blank cell read as zero because the published total proves it.
New transaction types	No rationale recorded.	Blank cell read as zero because the published total proves it.
New or modified transaction validity mechanisms	No rationale recorded.	Blank cell read as zero because the published total proves it.
Encoding changes (RLP/SSZ)	No rationale recorded.	Blank cell read as zero because the published total proves it.
New fork activation mechanism	No rationale recorded.	Blank cell read as zero because the published total proves it.
Engine API changes	No rationale recorded.	Blank cell read as zero because the published total proves it.
Transition-tool interface changes	No rationale recorded.	Blank cell read as zero because the published total proves it.
New invariant on pre-existing tests	No rationale recorded.	Blank cell read as zero because the published total proves it.
Security risks	No rationale recorded.	Blank cell read as zero because the published total proves it.
Edge/boundary conditions	No rationale recorded.	Blank cell read as zero because the published total proves it.
Cryptography	No rationale recorded.	Blank cell read as zero because the published total proves it.
Unspecified behavior requiring cross-client consensus	No rationale recorded.	Blank cell read as zero because the published total proves it.

Assessment provenance

Rubric: Checklist revision 2 · ethspecs/pm@3d8c0128c5
Evaluator: STEEL team · ethspecs/pm complexity_assessments
Source record: Open pull request #118: Update EIP-7668 complexity assessment to checklist revision 2 · checklist at 0125045895 · updated 2026-08-18
blob e0cc4d5614 · sha256 6020f3af4efa
Research record: research/tasks/09-hegota-human-assessment-snapshot/outputs/assessments/eip-7668.yaml · sha256 cba2a0be698b

Both assessments applied Checklist revision 2 (28 criteria) to EIP-7668 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.

LLM10Low

Human7Low

Δ total+3Same tier

Criteria19/28agree exactly · 6 differ by 1 · 3 differ by 2+

Complexity profiles side by side

LLM

Human

Largest disagreements: Encoding changes (RLP/SSZ) (+3), New invariant on pre-existing tests (+2), New test-framework primitives (−2), Patterns affecting pre-existing tests (+1), Edge/boundary conditions (+1)

Show differences only (9 criteria)

Per-criterion scores, Human versus LLM, ordered by the size of the difference
Criterion	LLM	Human	Δ	Agreement	Rationale from each source
Encoding changes (RLP/SSZ)	3	0	+3	Differ by 2+	Show rationale LLM This is an encoding-level change at the block and receipt interfaces: retained fields must carry a zero-length byte value. The rubric assigns 3 whenever a transaction, block, or interface encoding change is introduced. Human No rationale recorded.
New invariant on pre-existing tests	2	0	+2	Differ by 2+	Show rationale LLM A broad category of existing block and receipt tests gains a mechanical empty-value invariant even when the test is about another behavior. The package does not show that every fork test gains the assertion or that pre-fork vectors must be re-derived, so score 3 is not supported. Human No rationale recorded.
New test-framework primitives	0	2	−2	Differ by 2+	Show rationale LLM Testing an existing field for an empty byte value does not require a new expectation type, modifier, or helper on the evidence provided. Human 29 framework files under `packages/testing/src` touch the bloom: header and receipt types, blockchain builder, RPC/hive. Both types need a fork-conditional shape, 256 bytes before and zero-length after.
New block / header fields	0	1	−1	Differ by 1	Show rationale LLM The value constraint on an existing field changes, but no new block or header field is introduced. Human No field is added, an existing one is emptied. Deliberate departure: this anchor is binary 0/3 and recognises only additions. Actual removal is deferred to a future EIP.
Block syncing changes	2	1	+1	Differ by 1	Show rationale LLM Block/receipt ingestion gains two simple encoded-field validation rules, one at the block level and one at the receipt level, matching the multiple-simple-mechanism anchor. Human `fork.py` rejects `block_logs_bloom != block.header.bloom`; that becomes a zero-length requirement. Receipts need no separate check, since a wrong bloom already surfaces as a `receipt_root` mismatch.
Patterns affecting pre-existing tests	2	1	+1	Differ by 1	Show rationale LLM Pre-existing vectors that construct or validate blocks or receipts with the former bloom representation require updates across two broad output surfaces. The update is structurally mechanical, and the package does not establish the diverse test-category impact required for score 3. Human 1 hand-written test file references bloom, 0 under `tests/ported_static/`. Every fixture regenerates since block hashes move, but the sources stay put.
Performance risks	0	1	−1	Differ by 1	Show rationale LLM The proposal removes bloom-filter handling and introduces no new mechanism whose performance must be validated under this risk anchor. Human `eth_getLogs` might be affected and requires further review.
Edge/boundary conditions	1	0	+1	Differ by 1	Show rationale LLM The proposal introduces one simple boundary-prone rule—exactly zero bytes—applied at the block and receipt levels; tests must distinguish empty values from any non-empty representation. Human No rationale recorded.
Cross-EIP interactions	0	1	−1	Differ by 1	Show rationale LLM No numbered EIP dependency, modification, or conflict is identified, and the mentioned optional future cleanup is not required for this proposal to operate or be tested. Human EIP-7745 and EIP-8304 both replace what blooms were for, so whether this EIP is redundant or complementary to them needs deciding. Testable independently.
Added opcodes	0	0	0	Agree	Show rationale LLM No new opcode is introduced. Human No rationale recorded.
Modified opcodes	0	0	0	Agree	Show rationale LLM No existing opcode's behavior is modified or deprecated; bloom output handling changes outside the stated opcode behavior. Human No rationale recorded.
Added precompiles	0	0	0	Agree	Show rationale LLM No precompile is introduced. Human No rationale recorded.
Modified precompiles	0	0	0	Agree	Show rationale LLM No existing precompile logic or gas schedule is modified. Human No rationale recorded.
Added system contracts	0	0	0	Agree	Show rationale LLM No system contract is introduced. Human No rationale recorded.
Modified system contracts	0	0	0	Agree	Show rationale LLM No pre-existing system contract code, state, or behavior is directly or indirectly modified by a stated mechanism. Human No rationale recorded.
EVM Gas rule changes	0	0	0	Agree	Show rationale LLM No EVM gas-accounting rule is changed; the only opcode-related gas decision is to retain the existing LOG costs. Human No rationale recorded.
State-access ordering within opcode execution	0	0	0	Agree	Show rationale LLM The proposal does not move a state access or a gas charge within any opcode; it changes block and receipt output fields. Human No rationale recorded.
Blob gas accounting changes	0	0	0	Agree	Show rationale LLM No blob gas rule or mechanism is introduced or modified. Human No rationale recorded.
State gas accounting changes	0	0	0	Agree	Show rationale LLM No state-writing gas cost, state-gas charging site, budget, reservoir, or spill rule is changed. Human No rationale recorded.
New EVM gas refund	0	0	0	Agree	Show rationale LLM The proposal introduces no gas-refund mechanism. Human No rationale recorded.
New transaction types	0	0	0	Agree	Show rationale LLM No new transaction type is introduced. Human No rationale recorded.
New or modified transaction validity mechanisms	0	0	0	Agree	Show rationale LLM No existing transaction type's validity rules or intrinsic gas calculation are changed. Human No rationale recorded.
New fork activation mechanism	0	0	0	Agree	Show rationale LLM No special state transition or internal-variable modification at the fork-activation block is introduced. Human No rationale recorded.
Engine API changes	0	0	0	Agree	Show rationale LLM No new Engine API field or endpoint is introduced. Human No rationale recorded.
Transition-tool interface changes	0	0	0	Agree	Show rationale LLM Existing field values change, but no transition-tool interface field or new interface mechanism is introduced. Human No rationale recorded.
Security risks	0	0	0	Agree	Show rationale LLM No new mechanism that changes stakeholder security assumptions is introduced. Human No rationale recorded.
Cryptography	0	0	0	Agree	Show rationale LLM No cryptographic mechanism is added or modified by the proposal. Human No rationale recorded.
Unspecified behavior requiring cross-client consensus	0	0	0	Agree	Show rationale LLM For constructible cases within the proposal's stated surface, clients have a determinate required byte length at both locations, and the proposal does not expose a formerly unobservable choice that needs coordination. Human No rationale recorded.

Compare EIP-7668 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.