EIP-8021 calldata table function

Parse EIP-8021 builder codes from calldata with the functions.base_l2.call_data_8021 table function.

EIP-8021 calldata table function

EIP-8021 defines a standard for embedding builder identification codes at the end of transaction calldata.

Dune exposes this as the table function functions.base_l2.call_data_8021. It reads calldata from an input table, keeps the input columns, and adds parsed EIP-8021 fields for rows that contain a valid EIP-8021 suffix.

Rows without the EIP-8021 suffix are omitted from the result.

Syntax

SELECT *
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(<query>),
  calldata => DESCRIPTOR(<calldata_column>)
))

Arguments

• input: The input table or subquery that contains a calldata column.
• calldata: Optional descriptor pointing to the calldata column in input. If omitted, the function looks for a column named calldata.

The referenced calldata column must be varchar.

Output columns

The table function passes through the original input columns and adds:

Column	Type	Description
original_tx_data	varchar	Original calldata without the EIP-8021 suffix
schema_type	varchar	Parsed schema label: Schema 0: Canonical Registry, Schema 1: Custom Registry, Schema 2: CBOR, or Unknown Schema
codes_hex	varchar	Builder codes as hex
custom_registry_address	varchar	Custom registry address for schema 1, otherwise NULL
codes_readable	varchar	UTF-8 decoded builder codes
codes_array	array(varchar)	Builder codes split into an array
cbor_data	varchar	JSON representation of schema 2 CBOR payloads
erc_8021_suffix	varchar	The EIP-8021 magic bytes suffix

Examples

Parse transaction calldata from base.transactions

SELECT
  tx_hash,
  block_time,
  schema_type,
  codes_readable,
  codes_array
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(
    SELECT
      hash AS tx_hash,
      block_time,
      cast(data as varchar) AS calldata
    FROM base.transactions
    WHERE block_time >= now() - interval '7' day
  )
))
LIMIT 100

Use the default calldata column name

SELECT
  tx_hash,
  schema_type,
  codes_readable
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(
    VALUES
      (
        '0xdeadbeef',
        '0x722c6182000000000000000000000000000000000000000000000000000000000000000163625f77616c6c6574090080218021802180218021802180218021'
      )
  ) AS t(tx_hash, calldata)
))

Override the calldata column name

SELECT
  tx_hash,
  schema_type,
  codes_readable
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(
    VALUES
      (
        '0xdeadbeef',
        '0x722c6182000000000000000000000000000000000000000000000000000000000000000163625f77616c6c6574090080218021802180218021802180218021'
      )
  ) AS t(tx_hash, call_data),
  calldata => DESCRIPTOR(call_data)
))

Parse schema 2 CBOR calldata

SELECT
  schema_type,
  codes_readable,
  codes_array,
  cbor_data
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(
    VALUES
      (
        '0xabcda26161656d796170706177686d7977616c6c657400140280218021802180218021802180218021'
      )
  ) AS t(calldata)
))

Filter for a specific builder code

SELECT
  tx_hash,
  block_time,
  codes_readable
FROM TABLE(functions.base_l2.call_data_8021(
  input => TABLE(
    SELECT
      hash AS tx_hash,
      block_time,
      cast(data as varchar) AS calldata
    FROM base.transactions
    WHERE block_time >= now() - interval '7' day
  )
))
WHERE contains(codes_array, 'cb_wallet')
LIMIT 100

Supported schema types

• Schema 0: Canonical Registry: Builder codes plus the EIP-8021 suffix
• Schema 1: Custom Registry: Builder codes plus a custom registry address
• Schema 2: CBOR: CBOR-encoded builder metadata exposed through both codes_* fields and cbor_data

EIP-8021 suffix structure

Schema 0 and schema 1 are parsed from the end of calldata in this order:

Component	Size	Description
Builder codes	Variable	UTF-8 encoded builder identification codes
Registry address	20 bytes	Only present for schema 1
Codes length	1 byte	Length of the builder code payload
Schema ID	1 byte	0x00 or 0x01
Magic bytes	16 bytes	0x80218021802180218021802180218021

Schema 2 uses:

Component	Size	Description
CBOR payload	Variable	CBOR map containing builder metadata
CBOR length	2 bytes	Length of the CBOR payload
Schema ID	1 byte	0x02
Magic bytes	16 bytes	0x80218021802180218021802180218021

Use Cases

• Builder attribution: Track which wallet or tool produced a transaction
• Wallet analytics: Measure adoption of builder codes across applications
• ERC-4337 analysis: Parse builder metadata from UserOperation calldata
• Schema research: Compare canonical registry, custom registry, and CBOR-based usage

Notes

• The function currently expects calldata as varchar, not varbinary
• If your source column is varbinary (for example base.transactions.data), cast it to varchar before passing it into the table function
• Input rows without the EIP-8021 magic bytes are filtered out of the result
• Builder codes are typically comma-separated identifiers such as cb_wallet