Retrospective LLM-Based Complexity Evaluations

EIP complexity assessment

EIP-7807: SSZ execution blocks

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, consensus
LLM Completescore 34
Human Pending· No STEEL checklist existed on the ethspecs/pm default branch or in any open pull request at the snapshot.

LLM assessment

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

Scope at the cutoff. Prospective complexity assessment of EIP-7807 at the sealed Hegota snapshot, limited to its execution-layer effects: SSZ execution-block and header representation, block-hash computation, retained nested encodings, execution interfaces, JSON-RPC, devp2p, and the BLOCKHASH opcode. Consensus-layer-only behavior is excluded except where the EIP defines an execution-layer boundary.

34HighHigh
Evaluator
LLMChecklist v2
Confidence
Medium
Under-specified at assessment cutoff
Yes — 6 criteria affected
Plausible range
32–39 (High)
Snapshot
2026-08-25 · EIP revision ac450a4ab2 (2026-08-25)
Score bands · Checklist revision 2
  • Low <12
  • Medium 12–22
  • High ≥23

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

Complexity profile

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

Top complexity drivers

  1. Cross-EIP interactions4
  2. Modified opcodes3
  3. New block / header fields3
  4. Encoding changes (RLP/SSZ)3

Under-specified at assessment cutoff: Yes

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

Why: The Draft fixes the core SSZ payload and hash rule but does not normatively define transition-tool representation, Engine API endpoint/version/framing changes, devp2p wire and invalid-input handling, context-specific bounds for progressive lists, or historical and activation-boundary hash behavior. These are recorded as distinct gaps and are not used to inflate unrelated anchors.

Plausible total

32–39
recorded score 34 · plausible tiers High

Unresolved questions at the cutoff (5)
  • What exact transition-tool fields or encoding carry the new payload, header summary, receipts, and resulting block hash?
  • Which Engine API methods and versions use binary ForkDigest-context encoding, how are messages framed, and is block_hash removal normative?
  • How are SSZ blocks negotiated, encoded, and rejected in devp2p synchronization across the activation boundary?
  • What execution-layer bounds apply to each ProgressiveList and ProgressiveByteList before allocation, decoding, and Merkleization?
  • How must BLOCKHASH and external block-hash lookups treat pre-activation blocks when executed or queried after activation?
Notable ambiguities noted by the assessor (3)
  • The statement that the Engine API can drop block_hash and adopt binary encoding is rationale, not a normative endpoint specification; score 1 reflects one identified field modification while keeping confidence low.
  • The execution payload includes block_access_list and slot_number, but the package does not allocate their semantic origin among EIP-7807 and its fork/dependency context; the block/header-field anchor scores the explicit resulting definition.
  • Transactions and receipts retain EIP-2718 envelopes while withdrawals and the block access list retain RLP, so SSZ validation must preserve and commit to nested bytes without treating those inner objects as migrated SSZ values.

Criterion breakdown

EIP-7807 Hegotá: LLM criterion scores and rationale
CriterionScoreWhy this scoreEvidence / uncertainty
Cross-EIP interactionsExceptional4The block format has strong coordinated dependencies on three required EIPs and embeds EIP-2718 envelopes, EIP-7843 slot data, and EIP-7928 block access lists, so cross-EIP vectors must cover container/list roots, fork composition, and preserved or produced field bytes. Six identified interactions produce base score 3 plus the rubric's first +1 for three interacting EIPs beyond the first three.

Exceptional score: Six identified EIPs each contribute a coordinated test axis: the score-3 strong interdependency anchor plus the mandatory +1 for three additional EIPs beyond the first three yields 4.

  • eip.md · Front matter requires; Specification > Execution block; Rationale > Forward compatibility EIP-7807 requires EIPs 7495, 7773, and 7916 and retains EIP-2718 typed transaction and receipt envelopes inside the SSZ block.
  • supporting/eip-7495.md · Specification > ProgressiveContainer(active_fields) EIP-7495 supplies the forward-compatible container and depends on EIP-7916 progressive Merkleization.
  • supporting/eip-7773.md · Specification EIP-7773 is the required hard-fork meta proposal and identifies EIP-7843 SLOTNUM and EIP-7928 Block-Level Access Lists, whose outputs correspond to slot_number and block_access_list fields in EIP-7807.
  • supporting/eip-7916.md · Specification > ProgressiveList[type] and ProgressiveBitlist EIP-7916 supplies the unbounded progressive list and byte-list types used repeatedly by the new payload.
Confidence: High
Uncertainty: Several package-grounded structures have no EIP number in the sealed evidence and are recorded separately rather than guessed.
Interacting EIPs: EIP-2718, EIP-7495, EIP-7773, EIP-7916, EIP-7843, EIP-7928
Modified opcodes3The observable result of the pre-existing BLOCKHASH opcode changes from the prior block-hash computation, meeting the rubric's binary score-3 condition.
  • eip.md · Specification > Execution block hash computation BLOCKHASH uses ExecutionPayload.hash_tree_root() as the execution block hash.
Confidence: High
Uncertainty: Historical and fork-boundary BLOCKHASH cases are not explicitly resolved.
New block / header fields3The proposal introduces a new block/header field representation and explicitly includes fields in the new execution block, satisfying the binary score-3 anchor.
  • eip.md · Specification > Execution block A new 18-field SSZ ExecutionPayload includes block_access_list and slot_number and derives the header as an SSZ summary.
Confidence: High
Uncertainty: The package does not distinguish which individual field semantics originate in dependencies versus this migration; the new SSZ block/header definition is explicit regardless.
Encoding changes (RLP/SSZ)3A block-level RLP-to-SSZ encoding migration directly satisfies the rubric's binary score-3 condition.
  • eip.md · Abstract; Specification > Execution block Execution blocks and per-block tries migrate from Merkle-Patricia/RLP to normalized SSZ, with an SSZ-summary header and selected RLP elements retained inside the payload.
  • eip.md · Motivation > Optimized engine API; Rationale > Engine API The proposal targets binary SSZ encoding for Engine API exchange in place of textual JSON.
Confidence: High
Uncertainty: The exact Engine API wire specification is absent, but the normative execution-block encoding change alone determines this score.
Patterns affecting pre-existing tests3Existing block, header, receipt-root, block-hash, RPC, opcode, and synchronization expectations span diverse test categories and must be reworked for the new representation and hash, meeting the major-subset anchor.
  • eip.md · Specification > Execution block New blocks use a normalized SSZ payload and an SSZ-summary header while retaining typed-envelope and selected RLP-encoded elements.
  • eip.md · Specification > Execution block hash computation The SSZ hash-tree root becomes the block hash for opcode, JSON-RPC, devp2p, and consensus references.
Confidence: High
Uncertainty: Exact test inventories are unavailable by package policy, but the specification explicitly changes all listed execution-block contexts.
New test-framework primitivesUnder-specified3Generic construction, serialization, summary, and hash-tree-root support for the new permanent block format and its reusable progressive SSZ types is a framework-level primitive, not merely EIP-specific test code.
  • eip.md · Specification > Execution block Tests must construct and hash a ProgressiveContainer payload, ProgressiveLists, ProgressiveByteLists, and an SSZ-summary header.
  • supporting/eip-7495.md · Specification > ProgressiveContainer(active_fields) > Merkleization Progressive containers add active-field-aware progressive Merkleization.
  • supporting/eip-7916.md · Specification > Progressive Merkle tree; ProgressiveList[type] and ProgressiveBitlist Progressive list types add a recursive Merkle-tree shape and length-mixed roots.
Confidence: Medium
Uncertainty: The package excludes the actual test framework, so the amount of pre-existing SSZ support cannot be observed.
Security risks3Incorrect encoding, Merkleization, or hash-context handling can split consensus across block validation and cross-layer references and can expose inconsistent results through critical opcode, networking, and API surfaces, requiring broad review and fuzzing.
  • eip.md · Specification > Execution block hash computation; Security Considerations A SHA256-based SSZ root becomes block identity across BLOCKHASH, JSON-RPC, devp2p, and consensus references while sharing a namespace with keccak256 hashes.
  • eip.md · Specification > Execution block Receipt and request commitments and the derived header depend on correct SSZ list/container roots while selected inner elements retain other encodings.
Confidence: High
Uncertainty: The EIP dismisses significant cross-algorithm collision risk, but implementation-consistency risk across the listed critical components remains.
Performance risks3Whole-block serialization, parsing, Merkleization, networking, and hash lookup behavior interact with existing block-processing paths and cannot be fully benchmark-isolated; the proposal itself makes substantial performance claims.
  • eip.md · Motivation > Optimized engine API; Execution block hash computation The EIP claims roughly 50 percent smaller Engine API exchange and significantly improved encoding/parsing while changing block hashing across opcode, RPC, devp2p, and consensus references.
  • supporting/eip-7916.md · Motivation; Rationale > Why a recursive structure? Progressive Merkleization changes hash work and tree growth as list sizes increase.
Confidence: High
Uncertainty: No context-specific maximum list sizes or benchmark parameters are supplied.
Edge/boundary conditionsUnder-specified3Empty and non-empty lists, recursive subtree growth thresholds, variable-offset serialization, active-field roots, summary-versus-payload equivalence, and mixed nested encodings create multiple boundaries; progressive-tree thresholds require an elevated vector set.
  • eip.md · Specification > Execution block The payload combines fixed and variable fields, multiple progressive lists, retained typed/RLP elements, and a derived summary header.
  • supporting/eip-7916.md · Specification > Progressive Merkle tree Progressive roots change shape at recursively increasing chunk thresholds and define a distinct empty-list root.
  • supporting/eip-7495.md · Specification > ProgressiveContainer(active_fields) Progressive containers constrain active-field configurations and mix those bits into their Merkle roots.
Confidence: High
Uncertainty: Context-specific size bounds for unbounded progressive lists are not supplied by EIP-7807.
Block syncing changesUnder-specified2Replacing the block-level RLP/header validation path with SSZ and a new hash is a single complex synchronization-validation migration.
  • eip.md · Abstract; Specification > Execution block; Execution block hash computation The block and its per-block tries migrate from RLP/Merkle-Patricia representation to SSZ, and devp2p uses the new block hash.
Confidence: Medium
Uncertainty: The devp2p message encoding, validation sequence, fork negotiation, and invalid-block rules are not specified, preventing a supported score for multiple mechanisms.
Unspecified behavior requiring cross-client consensusUnder-specified2Constructible fork-boundary, historical BLOCKHASH, synchronization, and interface cases need localized cross-client agreement before vectors can be baselined; the gaps are material but do not establish the anchor-3 condition of newly observable previously unspecified execution behavior.
  • eip.md · Specification > Execution block hash computation; Rationale > Engine API The hash is mandated in all contexts, but fork-boundary/history behavior and the proposed binary Engine API version, framing, and endpoint mappings are not defined.
  • eip.md · Specification > Execution block; JSON-RPC The payload and logsBloom response are defined, while devp2p wire encoding and complete JSON-RPC field derivation are absent.
Confidence: Medium
Uncertainty: Implementations, devnets, discussions, and post-snapshot clarifications are prohibited, so only the Draft text's visible gaps are assessed.
Engine API changesUnder-specified1The package identifies one Engine API field modification (removing block_hash) and a transport-encoding change, but no new endpoint or set of new fields; the closest supported interface-impact anchor is 1.
  • eip.md · Rationale > Engine API The shared SSZ hash lets the Engine API drop the redundant block_hash field and adopt binary ForkDigest-context encoding.
Confidence: Low
Uncertainty: This behavior is stated in rationale rather than a normative endpoint/version specification, so the exact Engine API change is materially under-specified.
Cryptography1A well-known hash mechanism is newly used for execution block identity, fitting the single well-known cryptographic-mechanism anchor.
  • eip.md · Security Considerations The new SSZ block hash is SHA256-based and shares a namespace with existing keccak256-based block hashes.
Confidence: High
Uncertainty: The package asserts no significant collision risk but does not remove the need for cross-context hash-vector testing.
Show 15 zero-score criteria
Zero-score criteria (Checklist revision 2)
CriterionScoreWhy this scoreEvidence / uncertainty
Added opcodes0No opcode is added.
  • eip.md · Specification > Execution block hash computation The proposal refers to the existing BLOCKHASH opcode and defines no new opcode.
Uncertainty: None material within the package scope.
Added precompiles0No precompile is added.
  • eip.md · Specification (all subsections) No precompile address, input, output, behavior, or gas schedule is introduced.
Uncertainty: None material within the package scope.
Modified precompiles0No precompile is modified.
  • eip.md · Specification (all subsections) No existing precompile logic or gas accounting is mentioned or changed.
Uncertainty: None material within the package scope.
Added system contracts0No system contract or system action is added.
  • eip.md · Specification (all subsections) The proposal defines block data, hashing, and external representations and introduces no system contract.
Uncertainty: None material within the package scope.
Modified system contracts0Consumer incompatibility does not directly or indirectly modify a pre-existing system contract.
  • eip.md · Backwards Compatibility The identified compatibility impact concerns contracts that parse the previous header format, not changes to any system contract's code or state.
Uncertainty: No particular system contract is identified in the package.
EVM Gas rule changes0The proposal changes representation of gas amounts and fees, not EVM gas accounting.
  • eip.md · Specification > Gas amounts Gas values are regrouped into SSZ containers, with no rule changing how execution gas is charged.
Uncertainty: No gas-charging rule is specified anywhere in the proposal.
State-access ordering within opcode execution0No opcode state-access path or relative gas-charge position changes.
  • eip.md · Specification > Execution block hash computation The only opcode-specific change is the value of the block hash used by BLOCKHASH; no state access or gas-charge ordering is defined.
Uncertainty: None material within the package scope.
Blob gas accounting changes0Encoding blob-related values does not introduce or update blob gas accounting.
  • eip.md · Specification > Gas amounts Blob gas and blob fees are fields in SSZ containers, but their accounting rules are not modified.
Uncertainty: None material within the package scope.
State gas accounting changes0No state gas accounting mechanism or charging site is introduced.
  • eip.md · Specification > Gas amounts The specified gas structures contain regular and blob dimensions only and define no state-gas cost, budget, reservoir, or spill rule.
Uncertainty: None material within the package scope.
New EVM gas refund0No EVM gas-refund mechanism is introduced or changed.
  • eip.md · Specification > Gas amounts The proposal only represents gas amounts and fees and specifies no refund behavior.
Uncertainty: None material within the package scope.
New transaction types0The block container changes, but no new transaction type is introduced.
  • eip.md · Specification > Execution block Transaction elements retain their existing EIP-2718 typed-envelope representation.
  • supporting/eip-2718.md · Specification > Transactions EIP-2718 defines the existing typed or legacy transaction envelope carried unchanged by EIP-7807.
Uncertainty: None material within the package scope.
New or modified transaction validity mechanisms0No transaction validity rule or intrinsic gas calculation changes.
  • eip.md · Abstract; Specification > Execution block Individual transactions are unaffected and retain their existing typed-envelope representation.
Uncertainty: None material within the package scope.
New fork activation mechanism0A format transition alone does not meet this anchor's state/internal-variable modification condition.
  • eip.md · Specification (all subsections) The proposal defines the post-activation representation but specifies no state mutation or modification of an internal variable at the activation block.
Uncertainty: The activation point and handling of pre-fork history are not specified, but no activation-block mutation can be inferred.
Transition-tool interface changesUnder-specified0No transition-tool interface modification can be assigned from the sealed proposal text.
  • eip.md · Specification (all subsections) The specification defines execution-block, hashing, consensus-payload, and JSON-RPC behavior but no transition-tool field or transport contract.
Uncertainty: A transition tool may need representation support, but its required fields and mechanism are materially unspecified and cannot be inferred.
New invariant on pre-existing tests0The proposal changes existing expected values and encodings rather than adding a separate assertion to otherwise unchanged tests.
  • eip.md · Specification > Execution block; Execution block hash computation; JSON-RPC Existing block representation, hash, and logsBloom expectations change, but the EIP does not require tests unrelated to it to assert an additional product.
Uncertainty: Test-suite assertion structure is not present in the package; this score distinguishes changed expectations from the anchor's additional-invariant requirement.
Assessment provenance
Assessed EIP revision
ethereum/EIPs@ac450a4ab2 EIPS/eip-7807.md committed 2026-08-25 · information cutoff 2026-08-25T11:56:58Z
Current master · File history · blob 3f2dc991ac · sha256 bc279f875c28
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-7807.yaml · sha256 44920c361615
Supporting documents in the sealed package
supporting/eip-2718.md, supporting/eip-7495.md, supporting/eip-7773.md, supporting/eip-7916.md
Compare EIP-7807 with other assessmentsAll 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.

  • 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.