Retrospective LLM-Based Complexity Evaluations

EIP complexity assessment

EIP-4895: Beacon chain push withdrawals as operations

Assessed in Shanghai / Shapella. The score describes the EIP text available at the assessment cutoff, not the EIP as it stands today.

RetrospectiveShanghai / ShapellaAssessment cutoff 2022-03-11Included by cutoffLayers: execution, consensus
LLM Completescore 30
Human Not available· Human complexity assessments were not produced for this fork; only the LLM assessment exists.

LLM assessment

Evaluated on: · Spec revision: 2022-03-11 · 1ce607ac37

Scope at the cutoff. At the information cutoff, this draft proposed a new system-level withdrawal object, distinct from transactions, carrying a consensus-layer-supplied index, recipient, and amount. Post-fork execution blocks would gain an RLP-encoded withdrawals list and a header withdrawals root built like the transactions root; execution clients would validate the commitment and, after all user transactions, apply every withdrawal as an unconditional, gas-free balance increase. The draft left the fork timestamp and whether to add logs, receipts, and a receipts commitment unresolved, while assuming consensus-layer validation and a small bound on withdrawal volume.

30HighHigh
Evaluator
LLMChecklist v2
Confidence
Medium
Under-specified at assessment cutoff
Yes — 10 criteria affected
Plausible range
24–35 (High)
Assessment cutoff
2022-03-11 · EIP revision 1ce607ac37 (2022-03-11)
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

  1. New block / header fields3
  2. Encoding changes (RLP/SSZ)3
  3. Patterns affecting pre-existing tests3
  4. New invariant on pre-existing tests3

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: Material consensus behavior remains open in this draft. The explicit logs and receipts TODO could add observable execution outputs and another commitment; the consensus/execution transport, empty-list and field-presence behavior, index validity, list bound, and extreme balance-update semantics are also not specified sufficiently to baseline every constructible test.

Plausible total

24–35
recorded score 30 · plausible tiers High

Unresolved questions at the cutoff (6)
  • Do withdrawals produce logs or receipts, and if so what are their schemas and commitment rules?
  • Through what consensus/execution interface are withdrawals and any related commitments supplied and validated?
  • Is the withdrawals field mandatory when empty, and what is the required empty-list root at and after activation?
  • What list-level validity rules apply to withdrawal indices, including duplicates, gaps, and ordering across or within blocks?
  • What exact maximum list size is consensus-enforced, and how is violation represented or rejected at the execution layer?
  • How must unconditional balance increases behave at numeric limits and for previously absent recipient accounts?
Notable ambiguities noted by the assessor (4)
  • The term monotonically increasing does not state the validation scope or whether gaps are permitted.
  • The phrase assuming the block is well-formatted leaves malformed withdrawal-list validation outside the stated root check.
  • Unconditional and MUST not fail does not define arithmetic-limit or absent-account behavior.
  • The package establishes a consensus-layer dependency but identifies no EIP number for that change.

Criterion breakdown

EIP-4895 Shanghai / Shapella: LLM criterion scores and rationale
CriterionScoreWhy this scoreEvidence / uncertainty
New block / header fields3A new block field and a new header field directly trigger score 3 under this binary anchor.
  • eip.md · Specification / New field and commitment, lines 50-76 The execution block gains a withdrawals field and the execution header gains a withdrawals-root field.
Confidence: High
Encoding changes (RLP/SSZ)3The proposal changes block-body and header encoding by adding new RLP objects and fields. Any transaction-, block-, or interface-level encoding change maps directly to score 3 under this binary anchor.
  • eip.md · Specification / Withdrawal and block encoding, lines 40-62 A withdrawal has a new RLP schema, and the execution block gains a new field encoded as an RLP list of those objects.
  • eip.md · Specification / Commitment, lines 65-76 The execution header gains a new field containing the trie-root commitment to the newly encoded block data.
Confidence: High
Patterns affecting pre-existing testsUnder-specified3The block-body and header schemas, block-validity path, and state-transition path all change. Consequently a major and diverse set of existing post-fork block tests and fixtures must be reworked to construct and validate the new fields, including tests whose main subject is unrelated to withdrawals.
  • eip.md · Specification / New field and commitment, lines 50-84 Every post-fork block gains a withdrawals body field and header commitment, and block validity gains a root-equality check.
  • eip.md · Specification / State transition, lines 87-95 Block execution gains a post-transaction phase that can change account balances without gas or failure.
Confidence: High
Uncertainty: The draft does not say how an empty withdrawal list is represented, so the exact amount of mechanical reworking cannot be fixed from the text alone.
New invariant on pre-existing testsUnder-specified3Every post-fork block test gains a withdrawals-root consistency invariant regardless of what the test otherwise exercises. Fork-sensitive fixtures also have to distinguish the new post-fork header/body shape from the pre-fork shape, matching the broadest anchor.
  • eip.md · Specification / Commitment and block validity, lines 65-85 Each post-fork header must commit to its withdrawals list, and clients must assert that the header root equals the root computed from the body list.
Confidence: High
Uncertainty: Empty-list and field-presence semantics are not stated, and the unresolved receipts commitment could add another universal invariant.
Security risks3A fault can create incorrect ETH balances and crosses multiple critical components: consensus validation, execution block validation, commitment construction, and account state. The proposal itself calls for very high scrutiny, supporting extensive cross-component security review and fuzzing.
  • eip.md · Security Considerations, lines 122-125 Correct consensus-layer validation is critical to ETH withdrawal soundness, and the cross-layer ETH transfer has no current EVM analog and demands very high scrutiny.
  • eip.md · Specification / Commitment, validity, and transition, lines 65-95 Security spans body/header commitment validation and unconditional execution-state balance increases based on consensus-supplied data.
Confidence: High
Uncertainty: The unspecified cross-layer interface and validation details broaden, rather than eliminate, the review risk.
Edge/boundary conditionsUnder-specified3Multiple boundary-prone mechanisms combine: typed RLP values and list sizes, index progression and trie position, commitment mismatch, fork and processing order, and balance updates at account/value extremes. Their combinations require an elevated case matrix rather than a few isolated edge tests.
  • eip.md · Specification / System-level operation, lines 40-48 Withdrawal fields have distinct uint64, 20-byte, and 256-bit domains, with a monotonically increasing index and RLP serialization.
  • eip.md · Specification / Commitment, validity, and transition, lines 65-95 The proposal adds indexed-trie commitment validation, a strict after-transactions processing boundary, and unconditional balance updates.
Confidence: Medium
Uncertainty: Empty lists, duplicate or discontinuous indices, balance overflow, recipient account creation, and the exact consensus-layer list bound are not resolved in the draft.
Unspecified behavior requiring cross-client consensusUnder-specified3The draft leaves consensus-observable choices unresolved, most notably whether withdrawals create logs and receipts and add another commitment. It also omits constructible-case rules for empty or malformed lists, index progression, and unconditional balance-update extremes. Clients would have to agree and re-baseline block and state-transition vectors as those choices were amended, matching score 3.
  • eip.md · Specification / Constants and system-level operation, lines 32-48 The activation timestamp is TBD, and the text gives field types and a monotonic index without complete list-level validity semantics.
  • eip.md · Specification / Block validity and state transition, lines 79-97 Only root equality and unconditional balance increase are specified, followed by an explicit unresolved question about logs, receipts, and a receipts commitment.
Confidence: Medium
Uncertainty: No packaged implementation, devnet, test cases, or discussion record is available, so the assessment cannot establish whether any intended readings had already converged outside the sealed proposal.
Block syncing changesUnder-specified2Syncing clients must parse and validate multiple new block RLP structures and their commitment. These are multiple validation changes, but the trie-root construction intentionally reuses the existing transactions-root pattern, so the package does not establish a complex novel validation mechanism.
  • eip.md · Specification / Encoding and block validity, lines 48-85 Blocks gain an RLP list of RLP withdrawal objects, a header root, and validation that recomputes an indexed-trie commitment.
Confidence: High
Uncertainty: The unresolved possibility of receipts and another commitment could expand the syncing changes.
New test-framework primitivesUnder-specified2Tests need reusable withdrawal-object construction and expectations for its body list, commitment, and unconditional state effect. Those are new primitives reusable across this EIP's suite, while the package does not establish adoption by other EIPs' tests.
  • eip.md · Motivation and Specification, lines 24-28 and 38-76 The EIP deliberately creates a new system-level object domain plus block-list and trie-commitment structures separate from transactions.
Confidence: Medium
Uncertainty: No test design is included, and existing generic block-field and trie helpers might reduce the required extension to a minor one.
Cross-EIP interactionsUnder-specified2EIP-4895 is independently testable from the two numbered alternative designs, but it supersedes or conflicts with their withdrawal paths and therefore needs limited comparative coverage. More importantly, correct execution behavior depends on coordinated consensus-layer production and validation of the withdrawal list; that dependency is material but bounded in scope, fitting score 2 rather than an extensive multi-EIP score 3.
  • eip.md · Motivation, lines 21-28 The proposal contrasts its system operation with the EIP-4788-plus-contract pull design and the prior EIP-4863 transaction-based push design.
  • supporting/eip-4788.md · Motivation, lines 19-24 EIP-4788 states that exposing beacon state roots supports and is required for a different validator-withdrawal route.
  • supporting/eip-4863.md · Specification, lines 26-56 EIP-4863 specifies the same push-withdrawal objective as a special transaction type with ordering and balance-update semantics.
  • eip.md · Specification and Security Considerations, lines 40-46 and 122-125 Withdrawal data and its validation originate at the consensus layer, creating an essential cross-layer dependency whose EIP number is not identified.
Confidence: Medium
Uncertainty: The package identifies no EIP number for the required consensus-layer withdrawal scheduling and validation change, so it cannot be added to the numbered list or assessed in greater detail.
Interacting EIPs: EIP-4788, EIP-4863
Engine API changesUnder-specified1Supplying one new structured withdrawals list from consensus to execution implies at least one new payload/interface field. The text supports that limited consequence, but it neither names Engine API directives nor specifies multiple fields or a new endpoint.
  • eip.md · Specification / System-level operation, lines 40-46 The execution block receives a new withdrawals list whose three values are explicitly supplied from the consensus layer.
Confidence: Low
Uncertainty: The cross-layer transport is wholly unspecified; the eventual interface could require multiple fields or a new mechanism, and that cannot be inferred from later designs.
Transition-tool interface changesUnder-specified1A transition tool needs at least one new structured block input for the withdrawals list. On the text available, that is best supported as a single new field rather than a fully specified new interface mechanism.
  • eip.md · Specification / System-level operation and new field, lines 40-54 A new list of structured withdrawals, whose values are supplied by the consensus layer, becomes block input to execution processing.
Confidence: Medium
Uncertainty: The draft gives no transition-tool or consensus/execution interface schema; separate inputs or outputs for the commitment or any future receipts could raise the score.
Performance risksUnder-specified1The new root computation and bounded sequence of balance writes merit performance validation, but both can be benchmarked in isolation and the text asserts a small consensus-enforced bound. This fits the localized score-1 anchor.
  • eip.md · Rationale / Why no gas costs, lines 107-110 The consensus layer is said to enforce a small bound on withdrawal count, making execution-layer operational costs negligible in the broader block.
  • eip.md · Specification / Commitment and transition, lines 65-95 The work consists of computing a list trie root and applying one balance update per withdrawal.
Confidence: Medium
Uncertainty: The actual maximum withdrawal count and its enforcement rule are not specified.
Show 15 zero-score criteria
Zero-score criteria (Checklist revision 2)
CriterionScoreWhy this scoreEvidence / uncertainty
Added opcodes0The proposal defines no new EVM opcode.
  • eip.md · Rationale / Why not a new transaction type, lines 101-105 The new object is deliberately processed outside generic EVM execution.
Modified opcodes0No existing opcode's result or behavior is changed or deprecated.
  • eip.md · Specification / State transition, lines 87-95 The only execution change is a block-level post-transaction balance update with no EVM execution specified.
Added precompiles0The proposal introduces no precompile.
  • eip.md · Specification / System-level operation and transition, lines 38-48 and 87-95 The feature is a block-level object and direct state transition; no callable precompile is defined.
Modified precompiles0No pre-existing precompile logic or gas schedule is modified.
  • eip.md · Specification / State transition, lines 87-95 Withdrawal processing is specified as a direct balance update, with no reference to precompile logic or gas accounting.
Added system contracts0Calling the operation system-level does not introduce a system contract; no contract code, address, or state is specified.
  • eip.md · Motivation and Rationale, lines 24-28 and 101-105 The proposal chooses a new block-level operation rather than the cited user-space contract alternative or generic EVM execution.
Modified system contracts0No pre-existing system contract code, state, or behavior is modified directly or indirectly.
  • eip.md · Specification / State transition, lines 87-95 Withdrawals directly update recipient account balances and do not invoke or alter a contract.
EVM Gas rule changes0The proposal neither adjusts an existing EVM gas rule nor introduces a new gas-accounting mechanism; declaring the out-of-EVM operation gas-free is not itself a new EVM gas rule under this anchor.
  • eip.md · Specification / State transition, lines 87-95 Withdrawals perform unconditional balance increases after transactions and explicitly have no associated gas costs.
State-access ordering within opcode execution0No opcode is added or changed, and no state access or gas charge is reordered inside an opcode. The separately specified block-level processing order is outside the scope of this narrowly defined anchor.
  • eip.md · Specification / State transition, lines 87-95 Balance writes occur as block-level withdrawal processing after user transactions, not within opcode execution.
Blob gas accounting changes0No blob gas rule or accounting mechanism is introduced or modified.
  • eip.md · Specification, lines 30-97 The complete mechanism concerns withdrawal encoding, block commitment, validation, and balance updates, with no blob-gas mechanism.
State gas accounting changes0Although the operation writes account state, it introduces no state-gas cost, state-gas charging site, budget, reservoir, or spill rule covered by this anchor.
  • eip.md · Specification / State transition, lines 87-95 The proposal directly increases balances and states that the operation has no associated gas costs.
New EVM gas refund0The proposal introduces no EVM gas-refund mechanism.
  • eip.md · Specification / State transition, lines 89-95 The only specified value transfer is a gas-free unconditional balance increase; no refund behavior is defined.
New transaction types0The proposal intentionally does not introduce a transaction type.
  • eip.md · Motivation and Rationale, lines 26-28 and 101-105 The EIP explicitly separates withdrawals from user transactions as a new system-level operation object.
New or modified transaction validity mechanisms0Block validation gains a withdrawal-root rule, but no existing transaction type's validity rules or intrinsic gas calculation changes. That block-level rule is scored in the block and invariant anchors instead.
  • eip.md · Specification / System-level operation and state transition, lines 40-48 and 87-95 Withdrawals occupy a separate domain from transactions and are processed only after user transactions have already been applied.
New fork activation mechanism0Timestamp gating alone is not a new activation mechanism under this anchor, and the proposal specifies no irregular state or internal-variable modification at the activation block.
  • eip.md · Specification / Constants and activation, lines 32-36 The extensions begin at a still-TBD timestamp, with no activation-block-only state or internal-variable mutation specified.
  • eip.md · Specification / State transition, lines 87-95 Balance updates are ordinary per-block withdrawal processing after activation rather than a one-time fork transition.
Uncertainty: The activation timestamp value is TBD, but that does not change the mechanism score.
Cryptography0Reusing an existing commitment construction introduces no new or modified cryptographic mechanism.
  • eip.md · Specification / Commitment to withdrawals, lines 65-76 The commitment reuses the existing transactions-root construction with an indexed Merkle-Patricia trie.
Assessment provenance
Assessed EIP revision
ethereum/EIPs@1ce607ac37 EIPS/eip-4895.md committed 2022-03-11 · information cutoff 2022-03-11T12:28:57Z
Current master · File history · blob 20168103d6 · sha256 34436435c8cd
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/05-retrospective-complexity-assignment/outputs/fork-eips/shanghai/eip-4895.yaml · sha256 7a696963b410
Supporting documents in the sealed package
supporting/eip-4788.md, supporting/eip-4863.md
Compare EIP-4895 with other assessmentsAll Shanghai / Shapella 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.

  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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).
  • 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.).
  • 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.

  • 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.
  • 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.