Retrospective LLM-Based Complexity Evaluations

EIP complexity assessment

EIP-4844: Shard Blob Transactions

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

RetrospectiveCancun / DencunAssessment cutoff 2022-12-08Included by cutoffLayers: execution, consensus
LLM Completescore 43
Human Not available· Human complexity assessments were not produced for this fork; only the LLM assessment exists.

LLM assessment

Evaluated on: · Spec revision: 2022-12-05 · 7eac5f7f4a

Scope at the cutoff. This revision of EIP-4844 adds blob-carrying transactions. They use EIP-2718 type 0x05 with an SSZ-encoded `SignedBlobTransaction`. Blocks carry the minimal encoding, while the network/mempool encoding wraps the transaction with blobs, KZG commitments and an aggregated KZG proof that the EL must verify. A separate data-gas fee market is added: a new `excess_data_gas` header field, `fake_exponential` pricing, a target of 2 and a maximum of 4 blobs per block, and a data fee that is burned before execution and not refunded. The EIP also adds a `DATAHASH` opcode (0x49, 3 gas) and a KZG point-evaluation precompile (0x14, 50000 gas). Blob persistence is delegated to the consensus layer as sidecars.

43HighHigh
Evaluator
LLMChecklist v3
Confidence
Medium
Under-specified at assessment cutoff
Yes — 8 criteria affected
Plausible range
40–49 (High)
Assessment cutoff
2022-12-08 · EIP revision 7eac5f7f4a (2022-12-05)
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.

Top complexity drivers

  1. New transaction types3
  2. New or modified transaction validity mechanisms3
  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: This draft leaves several points unresolved. The data gasprice is computed from an ambiguous header (parent vs current). Intrinsic gas and the receipt format for type 0x05 are not stated. Precompile input-length and failure semantics are missing. It is unclear which wrapper checks also apply at block level. The Engine API exchange of blobs is not specified, and the KZG trusted setup is TBD.

Plausible total

40–49
recorded score 43 · plausible tiers High

Unresolved questions at the cutoff (8)
  • Does get_data_gasprice use the parent header's excess_data_gas or the current block's header (calc_data_fee takes `parent` but uses `header`)?
  • What is the intrinsic gas of a blob transaction, and how is calldata cost computed for an SSZ payload?
  • How does the point evaluation precompile handle inputs that are not 192 bytes, and how do assert failures behave (for example, consuming all gas)?
  • Do the version-byte and per-block blob-count checks apply at block validation, or only to network wrappers?
  • What is the receipt payload for type 0x05, and how is the transaction hash used in the trie and RPC?
  • Must a blob transaction contain at least one blob? Can `to` be None (contract creation)?
  • Which Engine API fields and methods carry excess_data_gas and blobs to the CL?
  • The balance check omits `value`. Is that intended?
Notable ambiguities noted by the assessor (5)
  • calc_data_fee(tx, parent) calls get_data_gasprice(header) while validate_block uses parent(block).header, so it is ambiguous which header prices the data fee.
  • The KZG trusted setup contents are TBD in the supplied consensus spec.
  • Wrapper-validation rules are described as EL verification "after signature verification", but whether they are block-validity or mempool-only rules is unclear.
  • Type aliases define Blob as a Vector of BLSFieldElement (uint256) in the EIP but as a ByteVector in the consensus spec.
  • The `hash` function used in kzg_to_versioned_hash is not named in the supplied text.

Criterion breakdown

EIP-4844 Cancun / Dencun: LLM criterion scores and rationale
CriterionScoreWhy this scoreEvidence / uncertainty
New transaction types3A distinct transaction envelope is introduced.
  • eip.md · Parameters — `BLOB_TX_TYPE` Bytes1(0x05) Adds a new EIP-2718 type, 0x05, with its own SSZ payload.
Confidence: High
New or modified transaction validity mechanismsUnder-specified3Validity now depends on chain history through the parent's excess_data_gas. Testing the price threshold therefore needs coordinated multi-block scenarios that drive the excess up, and transaction construction moves to SSZ signing. Shared transaction construction and scenario sequencing must be restructured, which is level 3.
  • eip.md · Gas accounting — validate_block Validity depends on the parent block's data gasprice and on combined affordability across gas and data gas.
  • eip.md · New transaction type — wrapper validity list Adds the versioned-hash version byte, count equality, commitment-hash binding and per-block blob limits.
  • eip.md · New transaction type — tx_hash/get_origin The signature is recovered over an SSZ hash_tree_root with a type prefix.
Confidence: Medium
Uncertainty: It is ambiguous which wrapper checks also apply at block level (for example, the version byte). Intrinsic gas is unspecified. The score could be 2 if multi-block construction is treated as local.
New block / header fields3A new header member is added to the EL execution header.
  • eip.md · Header extension excess_data_gas is added to the execution header after withdrawals_root.
Confidence: High
Encoding changes (RLP/SSZ)3Transaction, network wrapper and header schemas all change, so this is level 3.
  • eip.md · New transaction type — SignedBlobTransaction SSZ container Adds a new SSZ transaction payload, with distinct network and minimal encodings.
  • eip.md · Networking — BlobTransactionNetworkWrapper Adds a new peer-message payload containing blobs, commitments and an aggregated proof.
  • eip.md · Header extension — RLP list with excess_data_gas The header RLP schema gains a field.
Confidence: High
Block syncing changes3Multiple block-import validation rules change: decoding the new header field, validating excess_data_gas against the parent and blob count (complex), and the per-block blob limit. Decoding SSZ transactions in the block body is also new. This is level 3.
  • eip.md · Header extension Header RLP decoding gains excess_data_gas, which must equal calc_excess_data_gas(parent, new_blobs). This is complex because it depends on the parent and the block's transactions.
  • eip.md · Header extension — "For the first post-fork block, `parent.excess_data_gas` is evaluated as `0`" Adds special handling at the fork boundary.
  • eip.md · New transaction type — maximum blob commitments per block Adds a block-level blob-count limit.
Confidence: High
Edge/boundary conditions3Several independent boundary-sensitive rules are introduced. The affordability and data-gasprice checks form an elevated matrix: blob count × max_fee_per_data_gas × the parent's excess_data_gas (which sets the price) × gas limit × max_fee_per_gas × balance. These combinations jointly determine validity, so this is level 3.
  • eip.md · Header extension — calc_excess_data_gas The excess calculation clamps at zero against the target.
  • eip.md · New transaction type — "at most `MAX_DATA_GAS_PER_BLOCK // DATA_GAS_PER_BLOB` total blob commitments" Sets a per-block maximum of 4 blobs.
  • eip.md · Gas accounting — validate_block asserts The balance check combines gas*max_fee and data_gas*max_fee_per_data_gas, and max_fee_per_data_gas must be at least the data gasprice.
  • eip.md · Opcode to get versioned hashes — "if index < len(...)" Defines index bounds for DATAHASH.
  • eip.md · Point evaluation precompile — "MUST reject non-canonical field elements" Field elements must be strictly less than BLS_MODULUS.
Confidence: High
Uncertainty: The balance check omits value, which may change the expected boundary.
Cryptography3Multiple cryptographic mechanisms are added: pairing-based KZG point verification in the precompile, aggregated KZG verification with Fiat-Shamir in wrapper validation, and versioned-hash binding. The trusted setup is TBD and the KZG/Fiat-Shamir verification requires validation beyond established resources, so this is level 3.
  • eip.md · Cryptographic Helpers — verify_kzg_proof(), verify_aggregate_kzg_proof() The EL must run single-point and aggregated KZG verification.
  • supporting/ethereum-consensus-specs--specs-eip4844-polynomial-commitments.md · Trusted setup — "contents TBD" The trusted setup is not yet defined, so established test resources are not evidenced.
  • supporting/ethereum-consensus-specs--specs-eip4844-polynomial-commitments.md · compute_challenges Aggregation uses a Fiat-Shamir transcript that is a new protocol construction.
  • eip.md · Helpers — kzg_to_versioned_hash Adds a new versioned-hash derivation from commitments.
Confidence: High
Uncertainty: Whether hash() in kzg_to_versioned_hash is SHA-256 is not specified in the supplied text.
Blob gas accounting changes2This introduces a completely new blob-gas mechanism: pricing, a per-block limit, an excess accumulator and burn settlement. No blob-gas rules exist in the baseline to change, so the new mechanism does not alter baseline gas expectations. This is level 2.
  • eip.md · Gas accounting — calc_data_fee / get_data_gasprice Adds data gas, a per-blob gas amount (2**17) and an exponential price derived from excess_data_gas.
  • eip.md · Header extension — calc_excess_data_gas Adds the running excess update with a target of 2**18 and clamping at zero.
  • eip.md · Gas accounting — "deducted from the sender balance before transaction execution and burned, and is not refunded" Adds a new settlement rule for the data fee.
Confidence: High
Uncertainty: There is an inconsistency over whether the price uses the parent header or the current header (see UNSP). It affects expected values, not the level.
Engine API changesUnder-specified2Endpoint-level behavior (retrieving blobs for block production) and the excess_data_gas payload field are both implied, but the supplied documents define neither concretely. Level 2 is the best-supported score; level 3 is plausible.
  • eip.md · Header extension Execution payloads must carry excess_data_gas, which implies a payload field.
  • eip.md · Beacon chain validation — "the contents of the blobs are propagated separately, as a 'sidecar'" / "Honest validator: produce beacon blocks with blobs, publish the blobs sidecars" Blobs exist only in the EL mempool wrapper, so the CL must obtain them from the EL. This implies new EL→CL exchange behavior.
  • supporting/ethereum-consensus-specs--specs-eip4844 · tree listing — validator.md The validator spec that would define the exchange is listed but not supplied.
Confidence: Low
Uncertainty: The Engine API is not specified in the supplied documents, and validator.md and beacon-chain.md are missing. The score could range from 1 to 3.
Transition-tool interface changesUnder-specified2Multiple semantic fields change: parent/current excess_data_gas, plus transaction fields for data gas and versioned hashes. The invocation protocol has no clear new exchange mechanism, so this is level 2.
  • eip.md · Header extension — calc_excess_data_gas(parent, new_blobs) The tool needs the parent's excess_data_gas as input and must output or compute the current value.
  • eip.md · New transaction type — "single byte `BLOB_TX_TYPE` followed by an SSZ encoding" The tool's transaction input must accept type 0x05, which has SSZ-specific fields (max_fee_per_data_gas, blob_versioned_hashes).
  • eip.md · Gas accounting — validate_block Validity depends on the parent's data gasprice, so the environment must carry data-gas context.
Confidence: Low
Uncertainty: No transition-tool evidence was supplied. Accepting SSZ-encoded transactions could count as a new mechanism, which would make this level 3.
Patterns affecting pre-existing testsUnder-specified2Localized cases in several families need rework: invalid-opcode enumeration (0x49), and precompile-range or empty-account calls at 0x14. The header extension changes header construction, but the main effect of that is a new invariant scored under INV. There is no common rewrite across ordinary cases in multiple families, so this is level 2.
  • eip.md · Parameters — `HASH_OPCODE_BYTE` 0x49 A previously undefined opcode byte becomes valid, so baseline cases that expect 0x49 to be invalid change.
  • eip.md · Parameters — `POINT_EVALUATION_PRECOMPILE_ADDRESS` Bytes20(0x14) Address 0x14 becomes a precompile, so baseline calls or enumerations covering this address change their results.
  • eip.md · Header extension Header RLP gains a field, which changes block hashes for blocks built under the target fork.
Confidence: Medium
Uncertainty: Whether baseline tests actually touch 0x49 or 0x14 cannot be confirmed without a supplied suite.
New invariant on pre-existing tests2All blockchain tests in the target fork must produce and check excess_data_gas, including blocks without blobs. This is a universal assertion, but there is no evidence that pre-fork vectors must be re-derived, so it is level 2.
  • eip.md · Header extension — "extended with a new 256-bit unsigned integer field `excess_data_gas`" Every post-fork header has a new field that must be produced and validated.
Confidence: High
New test-framework primitivesUnder-specified2The target suite needs new construction abstractions: SSZ transaction building and signing, KZG commitment and proof generation, and versioned-hash derivation. These are mostly confined to blob-related tests, so this is level 2.
  • eip.md · New transaction type — SignedBlobTransaction / tx_hash Transactions require SSZ serialization and signing over hash_tree_root, which is a new construction abstraction compared with RLP transactions.
  • eip.md · Networking — BlobTransactionNetworkWrapper The network form needs generation of blobs, commitments and aggregated proofs.
  • eip.md · Point evaluation precompile Precompile tests need valid KZG commitment, proof and versioned-hash construction.
Confidence: Medium
Uncertainty: Supporting two encodings for one transaction (network and minimal) in shared block construction might affect other families, which would justify level 3.
Security risksUnder-specified2New validation boundaries at mempool ingress, and the EL/CL cross-verification of versioned hashes against sidecar blobs, need targeted integration review and fuzzing. This is level 2.
  • eip.md · Backwards Compatibility — Mempool issues Mempool DoS from large blobs.
  • eip.md · New transaction type — wrapper verification The binding between EL versioned hashes, commitments and blobs must hold, because the CL relies on it for availability.
  • supporting/ethereum-consensus-specs--specs-eip4844-polynomial-commitments.md · Trusted setup — "reusing the `mainnet` settings in public networks is a critical security requirement" KZG soundness depends on the setup.
Confidence: Medium
Uncertainty: The cross-layer data-availability trust split could be read as a shared invariant across components (level 3).
Performance risks2Component benchmarks are needed for the precompile. Targeted integrated benchmarks are needed for mempool ingress: large wrappers combined with aggregate KZG verification and the announce/request flow. This is a bounded interaction, so level 2.
  • eip.md · Point evaluation precompile — POINT_EVALUATION_PRECOMPILE_GAS 50000 The pairing-check cost needs benchmarking against the fixed gas price.
  • eip.md · Backwards Compatibility — Mempool issues Large blob transactions pose a mempool DoS risk, and propagation is announcement-only.
  • eip.md · Networking — validate_blob_transaction_wrapper Aggregated KZG verification over blobs of 4096 field elements each runs on mempool ingress.
Confidence: Medium
Cross-EIP interactions2EIP-1559 fee semantics need coordinated cases with data-gas affordability and burning. EIP-2718 envelope and trie handling need coordinated cases for SSZ payloads mixed with RLP types in blocks. The other interactions are local compatibility checks. This is level 2.
  • eip.md · New transaction type — "follow EIP-1559 semantics" Blob transactions combine base fee and priority fee with the separate data fee.
  • eip.md · New transaction type — EIP-2718 extended with "wrapper data" Two encodings of one typed transaction, with an SSZ payload, sit inside the typed envelope.
  • eip.md · Header extension excess_data_gas follows the EIP-4895 withdrawals_root.
  • eip.md · Backwards Compatibility — Mempool issues (EIP-5793) Type and size are announced in eth/68.
Confidence: Medium
Interacting EIPs: EIP-1559, EIP-2718, EIP-2930, EIP-4895, EIP-5793
Unspecified behavior requiring cross-client consensus2Several localized competing interpretations need agreement before expected results can be fixed: which header's excess_data_gas sets the price, the precompile's length and failure behavior, and intrinsic gas. This is level 2.
  • eip.md · Gas accounting — "def calc_data_fee(tx, parent)... get_data_gasprice(header)" The data fee function takes the parent but prices with `header`, while validate_block uses the parent header. These are competing outcomes for the price.
  • eip.md · Point evaluation precompile Input-length handling and failure semantics (an assert) are not specified.
  • eip.md · New transaction type Neither intrinsic gas nor the receipt payload for type 0x05 is stated, and it is unclear whether wrapper checks (version byte, blob limit) apply at block level.
Confidence: Medium
Uncertainty: Missing consensus-spec files might resolve some of these points.
Added opcodes1Exactly one simple instruction is added.
  • eip.md · Opcode to get versioned hashes — "takes as input one stack argument `index`" DATAHASH has no immediate data, a fixed one-in/one-out stack effect and a constant cost of 3 gas.
Confidence: High
Uncertainty: Behavior in non-blob transactions (an empty list, so presumably zero) is implied but not explicit.
Added precompilesUnder-specified1There is one precompile with a fixed input layout and constant gas, so it is simple. That gives level 1.
  • eip.md · Point evaluation precompile — "versioned_hash | z | y | commitment | proof" The input has a fixed 192-byte layout and constant gas of 50000.
Confidence: Medium
Uncertainty: Handling of inputs that are not 192 bytes is not specified. If variable lengths had to be supported, the precompile would be complex (level 2).
Show 9 zero-score criteria
Zero-score criteria (Checklist revision 3)
CriterionScoreWhy this scoreEvidence / uncertainty
Modified opcodes0No existing instruction changes.
  • eip.md · Opcode to get versioned hashes Only a new opcode at a previously undefined byte is added. No existing instruction semantics change.
Modified precompiles0No existing precompile changes.
  • eip.md · Point evaluation precompile Only a new precompile is added.
Added system contracts0No system contracts.
  • eip.md · Specification No protocol-designated EVM contract is introduced. The new address 0x14 is a native precompile.
Modified system contracts0No system contract changes.
  • eip.md · Specification No existing system contract is referenced or changed.
EVM Gas rule changesUnder-specified0No execution-gas accounting rule or settlement change is specified. The new accounting mechanism is data gas, which is scored under BLOB. Fixed costs for the opcode and precompile are ordinary fees.
  • eip.md · Opcode to get versioned hashes — "The opcode has a gas cost of `HASH_OPCODE_GAS`" The new opcode has a fixed cost of 3 gas, which is an ordinary instruction cost.
  • eip.md · Gas accounting — "data gas as a new type of gas. It is independent of normal gas" The new fee mechanism is data gas, which is separate from execution gas.
  • eip.md · Point evaluation precompile — "costs `POINT_EVALUATION_PRECOMPILE_GAS`" The precompile has a constant cost of 50000 gas, which is an ordinary fee rather than an accounting rule.
Uncertainty: Intrinsic gas for type-0x05 transactions is not stated. If clients treated it differently from EIP-1559/2930 intrinsic gas (for example, if calldata cost depended on SSZ encoding), this could become level 1.
State-access ordering within opcode execution0No instruction's state-access or gas-charge ordering changes, and no new state-accessing operation is introduced.
  • eip.md · Opcode to get versioned hashes DATAHASH reads only transaction context, not state.
  • eip.md · Point evaluation precompile The precompile does pure verification and does not access state.
State gas accounting changes0No state-gas accounting changes.
  • eip.md · Gas accounting Only blob data is priced in the new gas type. No state-write accounting is introduced.
New EVM gas refund0No refund mechanism is introduced.
  • eip.md · Gas accounting — "is not refunded in case of transaction failure" The data fee is explicitly non-refundable, and no refund mechanism is added.
New fork activation mechanism0No one-time state transition or account installation is required. The precompile is native.
  • eip.md · Header extension — "For the first post-fork block, `parent.excess_data_gas` is evaluated as `0`" This is rule selection at the fork boundary, not a state migration.
Assessment provenance
Assessed EIP revision
ethereum/EIPs@7eac5f7f4a EIPS/eip-4844.md committed 2022-12-05 · information cutoff 2022-12-08
Current master · File history · blob df8423c5b8 · sha256 014ecdd0aeff
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/retrospective/outputs/assessments/cancun/eip-4844.yaml · sha256 55531eeea542
Supporting documents supplied with the EIP
supporting/eip-1559.md, supporting/eip-2718.md, supporting/eip-2930.md, supporting/eip-4895.md, supporting/eip-5793.md, supporting/ethereum-consensus-specs--specs-eip4844, supporting/ethereum-consensus-specs--specs-eip4844-polynomial-commitments.md
Compare EIP-4844 with other assessmentsAll Cancun / Dencun 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 · 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.
  • 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.
  • 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 · 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.

  • 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 · 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.