Configuring PostParams on Art Blocks Tokens#

What Are PostParams?#

PostParams (Post-Mint Parameters / PMP) are on-chain configurable parameters embedded in certain Art Blocks art scripts. After minting, authorized wallets can set values that directly affect the token's on-chain visual output — no re-mint required.

Each parameter has an authOption controlling who can configure it:

authOptionWho can configureArtistProject artist onlyTokenOwnerCurrent token owner onlyAddressA specific configured contract address onlyArtistAndTokenOwnerArtist or token ownerArtistAndAddressArtist or specific contract addressTokenOwnerAndAddressToken owner or specific contract addressArtistAndTokenOwnerAndAddressArtist, token owner, or specific contract address

Token ID Format#

<contract_address>-<token_number>

Example: 0xa7d8d9ef8d8ce8992df33d8b8cf4aebabd5bd270-78000000

Workflow#

Step 1 — Discover available params#

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discover_postparams(tokenId, chainId?)

Returns: param keys, types, value constraints, current values, and authOption for each param. Always show this to the user before asking for values — they need to know what's configurable and within what constraints.

Step 2 — Build the configuration transaction#

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build_configure_postparams_transaction(tokenId, values, chainId?, signerAddress?)

• values is a key-value object — keys must match param keys from discover_postparams
• Always pass signerAddress when known — needed to determine artist status and validate authorization
• One transaction configures all passed params at once

Returns an unsigned transaction object ready to sign and submit.

Value Formats by Type#

TypeFormatExampleBool``"true" or "false"``"true"``SelectOne of the allowed option strings"red"``Uint256RangeNon-negative integer string"42"``Int256RangeInteger string (can be negative)"-5"``DecimalRangeDecimal string"3.14"``HexColorHex color with #``"#FF0000"``TimestampUnix timestamp in seconds"1700000000"``StringAny text string"hello world"

Notes#

• Always call discover_postparams first — param keys and types are project-specific and not guessable
• String params: the configuringArtistString flag on the built transaction depends on whether signerAddress matches the project artist — always pass signerAddress for String type params
• Authorization: if the user's address doesn't match the authOption for a param, the transaction will revert on-chain. Check authOption against the user's role before proceeding
• One transaction per call, but you can configure multiple params in a single call by passing multiple keys in values