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 2026-10-07EIP-8081: CFILayers: execution

LLM Completescore 12

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 32026-10-08 · Opus 5.5 · snapshot · 12 Human · Checklist revision 2Available in open PR · 7 CompareHuman vs LLM · shared criteria

Evaluated on: 2026-10-08 · Spec revision: 2026-10-07 · 6dac5e7491 · EIP-8081 list: CFI

Scope at the cutoff. EIP-7668 requires the logs bloom to be empty (0 bytes long) in both the execution block header and every transaction receipt. Clients would no longer compute or validate a 2048-bit bloom. The header field is not removed; the Rationale leaves that to a future EIP. LOG gas costs stay the same. The only normative text is two sentences, so the work is mostly about encoding, header validation and receipt-root changes rather than new execution semantics.

12MediumMedium

Evaluator: LLMChecklist v3
Confidence: Medium
Under-specified at assessment cutoff: Yes — 4 criteria affected
Plausible range: 10–16 (Low–Medium)
Snapshot: 2026-10-07 · EIP revision 6dac5e7491 (2026-10-07)

Score bands · Checklist revision 3

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 two-sentence specification sets the consensus rule (empty, 0-byte blooms in the header and receipts). It does not say how the change appears in the Engine API execution payload, the transition-tool output or network receipt messages, and it gives no explicit fork-activation wording.

Plausible total

10–16
recorded score 12 · plausible tiers Low, Medium

Affected criteria (4)

Block syncing changes (2)
Engine API changes (1)
Transition-tool interface changes (1)
Patterns affecting pre-existing tests (2)

Unresolved questions at the cutoff (4)

How is an empty logsBloom represented in the Engine API ExecutionPayload (a field type change, omission, or a new payload version)?
Must the transition tool emit an empty logsBloom, or omit it?
Is a 256-byte all-zero bloom explicitly invalid after the fork? The text implies yes through "0 bytes long".
How are receipts with empty blooms exchanged over the peer protocol?

Notable ambiguities noted by the assessor (3)

The discussions-to URL names EIP-7653 for the same title, but EIP-7653's text was not supplied, so its relationship to the target is unknown.
"Empty (ie. 0 bytes long)" conflicts with today's fixed-length 256-byte bloom type; Engine API and transition-tool representations are not specified.
Status is Stagnant; no activation details are given beyond the general requirement.

Criterion breakdown

EIP-7668 Hegotá: LLM criterion scores and rationale
Criterion	Score	Why this score	Evidence / uncertainty
Encoding changes (RLP/SSZ)	3	Two serialized fields change format: logsBloom in the execution header (256 bytes becomes 0 bytes) and the bloom field in the receipt encoding, which feeds receiptsRoot and peer receipt messages.	eip.md · Specification — "(ie. 0 bytes long)" In the block header RLP, logsBloom changes from a 256-byte string to an empty string. In receipt encoding, the bloom field changes from 256 bytes to empty. Confidence: High
Block syncing changesUnder-specified	2	Multiple simple structural rules change: the header bloom length during RLP decoding, and the header bloom value check (the aggregate-of-receipts check is replaced by an emptiness check). Both must be tested by importing blocks.	eip.md · Specification — "The logs bloom of an execution block is now required to be empty" Header decoding and validation of logsBloom change. A 0-byte field is now required instead of a 256-byte field equal to the aggregate of the receipt blooms. eip.md · Specification — "The logs bloom of a transaction receipt is now required to be empty" Receipt encoding changes, which affects receiptsRoot validation during import. Confidence: Medium Uncertainty: If the changed receiptsRoot validation (which depends on execution) counts as a changed complex rule, this could be 3.
Patterns affecting pre-existing testsUnder-specified	2	Some baseline tests explicitly expect bloom values, such as tests of LOG output, receipt contents and header validation with an invalid logsBloom. Their expected results must change. That is localized rework across several families, which fits level 2. Receipts roots and block hashes change in every block fixture, but the filling framework regenerates them mechanically, without rewriting test inputs or steps.	eip.md · Specification — "The logs bloom of an execution block is now required to be empty" Every post-fork header's bloom value changes from the OR of the receipt blooms to an empty byte string. eip.md · Specification — "The logs bloom of a transaction receipt is now required to be empty" The encoding of every receipt changes, so expected receipts roots change. Confidence: Medium Uncertainty: If the universal change to expected receiptsRoot and block hash is treated as reworking ordinary cases in every family, level 3 could apply.
Engine API changesUnder-specified	1	The execution payload's logsBloom field (normally a fixed 256 bytes) must represent an empty value, so its type changes. That is one field change. The EIP specifies no endpoint change.	eip.md · Specification — "The logs bloom of an execution block is now required to be empty (ie. 0 bytes long)" The execution block's logsBloom becomes 0 bytes. The execution payload carries this field. Confidence: Low Uncertainty: The EIP does not mention the Engine API. A new versioned payload method might be needed (could be 2), or the field could be omitted or zero-filled at the API level (could be 0).
Transition-tool interface changesUnder-specified	1	The transition tool's logsBloom output (block-level and per receipt, the same semantic field) changes format and meaning from a fixed 256-byte value to empty. That is one semantically changed field with no new mechanism.	eip.md · Specification — "(ie. 0 bytes long)" The logs bloom changes from a fixed 256-byte value to an empty byte string. The transition tool outputs logsBloom in its result and receipts. Confidence: Low Uncertainty: No transition-tool documentation was supplied. If header and receipt blooms count as separate fields, this could be 2. If the existing schema already allows variable-length hex, it could be 0.
New test-framework primitives	1	Header and receipt representations need a fork-aware local extension so the bloom field can be empty (variable length instead of a fixed 256 bytes). No new abstraction is needed.	eip.md · Specification — "(ie. 0 bytes long)" The bloom type in headers and receipts must allow an empty value after the fork. Confidence: Medium
Edge/boundary conditions	1	There is one boundary-sensitive mechanism: the bloom length/emptiness rule, tested at the fork transition and at lengths 0, 256 and other values.	eip.md · Specification — "required to be empty (ie. 0 bytes long)" Bloom length validity changes at the fork. Post-fork blooms of 0 bytes are valid; 256-byte (even all-zero) or other lengths are invalid. The pre-fork rule is the reverse. Confidence: Medium
Unspecified behavior requiring cross-client consensus	1	The surrounding text supports one intended consensus outcome: the RLP fields are kept as empty strings. Only localized representation details, such as the Engine API payload field, are omitted, and there are no competing consensus interpretations.	eip.md · Specification Says bloom is "empty (ie. 0 bytes long)" but does not say how this is represented in the Engine API execution payload, the transition-tool output or peer receipt messages, and gives no activation-boundary wording. Confidence: Medium Uncertainty: Whether an all-zero 256-byte bloom might be considered "empty" by some readers. The text's "0 bytes long" suggests not.

Show 20 zero-score criteria

Zero-score criteria (Checklist revision 3)
Criterion	Why this score	Evidence / uncertainty
Added opcodes	None.	eip.md · Specification No new instructions.
Modified opcodes	LOG semantics (stack, memory, emitted logs) are unchanged. Bloom aggregation is a block/receipt-level artifact, not instruction semantics.	eip.md · Rationale — "Gas costs of LOG are not reduced" LOG instructions keep their gas and still emit logs. Only the bloom aggregation outside the EVM is dropped.
Added precompiles	None.	eip.md · Specification No precompile is introduced.
Modified precompiles	None.	eip.md · Specification No precompile is changed.
Added system contracts	None.	eip.md · Specification No contract is introduced.
Modified system contracts	No existing system contract's behavior changes. System-call logs, if any, simply stop contributing to a bloom.	eip.md · Specification No system contract is referenced.
EVM Gas rule changes	No execution-gas charging, metering or settlement rule changes.	eip.md · Rationale — "Gas costs of LOG are not reduced" The EIP explicitly keeps LOG gas costs unchanged.
State-access ordering within opcode execution	No instruction's state-access or gas-charge ordering changes.	eip.md · Specification Only the bloom contents in the header and receipts are constrained. No instruction ordering is touched.
Blob gas accounting changes	No blob-gas accounting change.	eip.md · Specification Nothing about blob gas.
State gas accounting changes	No state-gas accounting change.	eip.md · Specification No state-gas rules are mentioned or changed.
New EVM gas refund	No new refund.	eip.md · Specification No refund mechanism is introduced.
New transaction types	None.	eip.md · Specification No transaction envelope is introduced.
New or modified transaction validity mechanisms	No transaction-validity change.	eip.md · Specification Only bloom fields are constrained. Transaction eligibility and intrinsic gas are untouched.
New block / header fields	Only the value and length of an existing field change. No header member is added.	eip.md · Rationale — "A future EIP can later clean up by removing this field entirely" The existing logsBloom field is kept but must be empty. No field is added.
New fork activation mechanism	No activation-specific state transition. This is only rule selection at the fork.	eip.md · Specification The rule simply applies to post-fork blocks. No state migration or code installation.
New invariant on pre-existing tests	No new output field is created. Changed expected bloom values are rework counted under PAT.	eip.md · Specification The bloom fields already exist. Only their required value or length changes.
Security risks	No new security invariant or trust boundary. Consensus-split risk from bloom validation is covered by SYNC and ENC testing.	eip.md · Security Considerations — "no security concerns are raised" No new features are introduced or made cheaper.
Performance risks	No additional or changed workload needs performance validation.	eip.md · Rationale — "remove the need to handle blooms from clients" Work is removed, not added.
Cryptography	Dropping the keccak-based bloom construction does not add or change any cryptographic validation rule.	eip.md · Specification Bloom computation is removed. No cryptographic verification or signing rule is added or changed.
Cross-EIP interactions	The supplied text names no EIP whose behavior interacts with the target. The EIP-7653 reference is provenance only. Receipt bloom emptiness applies the same way to every receipt type, so it can be tested independently.	eip.md · Preamble — discussions-to URL "eip-7653-remove-bloom-filters" EIP-7653 appears only in a discussion URL slug. No behavioral interaction is described. Uncertainty: EIP-7653 was not supplied. It might be a duplicate or an alternative proposal, which would make it a competing design rather than an interaction. Typed-receipt EIPs might warrant local per-type checks, but the target does not state this.

Assessment provenance

Assessed EIP revision: ethereum/EIPs@6dac5e7491 EIPS/eip-7668.md committed 2026-10-07 · information cutoff 2026-10-07T22:23:55Z
Current master · File history · blob fbd998df26 · sha256 816047a55941
Rubric: Checklist revision 3 · ethspecs/pm@fe2f793b03
Evaluator: Opus 5.5 (claude-opus-5-5) at high effort, one tool-less call per EIP · isolation bubblewrap_claude_p_no_tools_v1
Source record: Frozen research record research/tasks/10-opus-v3-reassessment/prospective/outputs/assessments/hegota-2026-10-08/eip-7668.yaml · sha256 8ecbea100b3e

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

The LLM applied checklist revision 3 and the human reviewers revision 2 to EIP-7668 in Hegotá. Revision 3 phrases the same criteria more precisely; differences cover the 28 criteria both revisions share, and each total keeps its own revision. Δ is LLM minus Human.

Using the latest scored LLM evaluation for this checklist: 2026-10-08 · spec 2026-10-07 · 6dac5e7491. The Human and LLM assessments may use different spec revisions.

LLM12Medium

Human7Low

Δ total+5Tiers differ: Medium vs Low

Criteria17/28agree exactly · 10 differ by 1 · 1 differ by 2+

Complexity profiles side by side

LLM

Human

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

Show differences only (11 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 Two serialized fields change format: logsBloom in the execution header (256 bytes becomes 0 bytes) and the bloom field in the receipt encoding, which feeds receiptsRoot and peer receipt messages. Human No rationale recorded.
New block / header fields	0	1	−1	Differ by 1	Show rationale LLM Only the value and length of an existing field change. No header member is added. 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 Multiple simple structural rules change: the header bloom length during RLP decoding, and the header bloom value check (the aggregate-of-receipts check is replaced by an emptiness check). Both must be tested by importing blocks. 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.
Engine API changes	1	0	+1	Differ by 1	Show rationale LLM The execution payload's logsBloom field (normally a fixed 256 bytes) must represent an empty value, so its type changes. That is one field change. The EIP specifies no endpoint change. Human No rationale recorded.
Transition-tool interface changes	1	0	+1	Differ by 1	Show rationale LLM The transition tool's logsBloom output (block-level and per receipt, the same semantic field) changes format and meaning from a fixed 256-byte value to empty. That is one semantically changed field with no new mechanism. Human No rationale recorded.
Patterns affecting pre-existing tests	2	1	+1	Differ by 1	Show rationale LLM Some baseline tests explicitly expect bloom values, such as tests of LOG output, receipt contents and header validation with an invalid logsBloom. Their expected results must change. That is localized rework across several families, which fits level 2. Receipts roots and block hashes change in every block fixture, but the filling framework regenerates them mechanically, without rewriting test inputs or steps. 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.
New test-framework primitives	1	2	−1	Differ by 1	Show rationale LLM Header and receipt representations need a fork-aware local extension so the bloom field can be empty (variable length instead of a fixed 256 bytes). No new abstraction is needed. 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.
Performance risks	0	1	−1	Differ by 1	Show rationale LLM No additional or changed workload needs performance validation. Human `eth_getLogs` might be affected and requires further review.
Edge/boundary conditions	1	0	+1	Differ by 1	Show rationale LLM There is one boundary-sensitive mechanism: the bloom length/emptiness rule, tested at the fork transition and at lengths 0, 256 and other values. Human No rationale recorded.
Cross-EIP interactions	0	1	−1	Differ by 1	Show rationale LLM The supplied text names no EIP whose behavior interacts with the target. The EIP-7653 reference is provenance only. Receipt bloom emptiness applies the same way to every receipt type, so it can be tested independently. 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.
Unspecified behavior requiring cross-client consensus	1	0	+1	Differ by 1	Show rationale LLM The surrounding text supports one intended consensus outcome: the RLP fields are kept as empty strings. Only localized representation details, such as the Engine API payload field, are omitted, and there are no competing consensus interpretations. Human No rationale recorded.
Added opcodes	0	0	0	Agree	Show rationale LLM None. Human No rationale recorded.
Modified opcodes	0	0	0	Agree	Show rationale LLM LOG semantics (stack, memory, emitted logs) are unchanged. Bloom aggregation is a block/receipt-level artifact, not instruction semantics. Human No rationale recorded.
Added precompiles	0	0	0	Agree	Show rationale LLM None. Human No rationale recorded.
Modified precompiles	0	0	0	Agree	Show rationale LLM None. Human No rationale recorded.
Added system contracts	0	0	0	Agree	Show rationale LLM None. Human No rationale recorded.
Modified system contracts	0	0	0	Agree	Show rationale LLM No existing system contract's behavior changes. System-call logs, if any, simply stop contributing to a bloom. Human No rationale recorded.
EVM Gas rule changes	0	0	0	Agree	Show rationale LLM No execution-gas charging, metering or settlement rule changes. Human No rationale recorded.
State-access ordering within opcode execution	0	0	0	Agree	Show rationale LLM No instruction's state-access or gas-charge ordering changes. Human No rationale recorded.
Blob gas accounting changes	0	0	0	Agree	Show rationale LLM No blob-gas accounting change. Human No rationale recorded.
State gas accounting changes	0	0	0	Agree	Show rationale LLM No state-gas accounting change. Human No rationale recorded.
New EVM gas refund	0	0	0	Agree	Show rationale LLM No new refund. Human No rationale recorded.
New transaction types	0	0	0	Agree	Show rationale LLM None. Human No rationale recorded.
New or modified transaction validity mechanisms	0	0	0	Agree	Show rationale LLM No transaction-validity change. Human No rationale recorded.
New fork activation mechanism	0	0	0	Agree	Show rationale LLM No activation-specific state transition. This is only rule selection at the fork. Human No rationale recorded.
New invariant on pre-existing tests	0	0	0	Agree	Show rationale LLM No new output field is created. Changed expected bloom values are rework counted under PAT. Human No rationale recorded.
Security risks	0	0	0	Agree	Show rationale LLM No new security invariant or trust boundary. Consensus-split risk from bloom validation is covered by SYNC and ENC testing. Human No rationale recorded.
Cryptography	0	0	0	Agree	Show rationale LLM Dropping the keccak-based bloom construction does not add or change any cryptographic validation rule. 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 · not in checklist revision 1
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 · not in checklist revision 1
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 · not in checklist revision 1
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 · not in checklist revision 1
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 · not in checklist revision 1
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.