Buy a license and mint a remix

A Rawchunks license enables its ongoing remix workflow. Purchasing reduces the original’s available allocation; making another remix does not consume the buyer’s license. Remixes cannot be licensed or remixed again in this workflow. Use the same network for the original, license purchase and remix mint. The license price comes from the confirmed chain record, not a cached catalog price.

Verify the original

Use the EVM setup and factoryAbi from Factory reads. Set sourceSongId to the original’s catalog ID. Load it with the request client, then read its contract song:

const sourceProject = await api.get(`/api/songs/${encodeURIComponent(sourceSongId)}`);
const original = sourceProject.song;
if (!original.network || !original.chain_song_id || !original.metadata_cid || original.source) {
  throw new Error('Choose a minted original');
}
if (original.network !== `eip155:${publicClient.chain.id}`) throw new Error('Select the original network');
const originalSongId = BigInt(original.chain_song_id);
const state = await publicClient.readContract({
  address: evmContracts.factory, abi: factoryAbi,
  functionName: 'getSong', args: [originalSongId],
});
if (state.creator.toLowerCase() !== original.creator.toLowerCase() ||
    state.metadataUri !== `ipfs://${original.metadata_cid}` || state.isRemix) {
  throw new Error('Catalog and chain song do not match');
}

Buy and confirm

Follow Remix’s purchase example with this originalSongId, its verified state and the buyer’s connected wallet. It reads existing rights, approves the actual settlement token when needed, sends buyLicense and verifies Factory.hasLicense after confirmation. Show the chain price and settlement currency before requesting signatures. Store the approval and purchase hashes as soon as your wallet returns them. Recover an interrupted confirmation from those hashes before retrying. For license payments, 80% goes to the original creator and 20% to the Rawchunks treasury. Session service fees and wallet costs are separate.

Open and edit the draft

const draft = await api.post(`/api/songs/${encodeURIComponent(original.id)}/remix`);
const remixSongId = draft.id;

Check the caller’s chain license before this request. The REST draft route does not purchase or verify that license. It creates a private song with source linked to the original and zero license allocation. Use the returned ID for editing.

Mint the finished variation

Pin the finished draft JSON to get remixCid, using the metadata step. Set metadataUri to ipfs:// followed by remixCid. In Remix’s variation call, use:

Field	Value
`originalSongId`	The confirmed original ID above
`licenseAmount`, `licensePrice`	`0n`
`streamPrice`	`parseUnits(String(finishedDraft.stream_price), 6)` from `viem`
`metadataUri`	The finished variation’s IPFS URI

Keep the original and remixer identities in the final metadata. After the successful receipt, use the Factory event example to obtain mintedId. Check the new song’s creator, URI, isRemix = true and parentSongId = originalSongId. Then record the result with the remixer’s request headers:

await api.patch(`/api/songs/${encodeURIComponent(remixSongId)}`, {
  metadata_cid: remixCid,
  chain_song_id: mintedId.toString(),
  tx_hash: receipt.transactionHash,
  network: `eip155:${publicClient.chain.id}`,
  public: true,
});

A mint or license button does not establish copyright ownership, exclusivity or permission for outside distribution. Obtain any additional rights your product needs from the rights holder. The API and contract enforce the Rawchunks workflow described here. For Solana accounts, use the Solana license and remix example.

Overview

Integration basics

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Library and publishing

Buy a license and mint a remix

Verify the original

Buy and confirm

Open and edit the draft

Mint the finished variation

​Verify the original

​Buy and confirm

​Open and edit the draft

​Mint the finished variation

Verify the original

Buy and confirm

Open and edit the draft

Mint the finished variation