Migrate Removed Deprecated APIs

The next major CCC release removes compatibility APIs that had direct replacements or no runtime effect. Most migrations are mechanical. The Client, Requestor, Transport, and SSRI changes additionally make resource ownership explicit.

Migration checklist

Removed API	Replacement
`epochFrom(value)`	`Epoch.from(value)`
`epochFromHex(value)`	`Epoch.fromNum(value)`
`epochToHex(value)`	`Epoch.from(value).toPackedHex()`
`epoch[0]`, `epoch[1]`, `epoch[2]`	`epoch.integer`, `.numerator`, `.denominator`
Transaction methods ending in `At`	The same method name without `At`
`transaction.stringify()`	`ccc.stringify(transaction)`
`Address.fromString(value, clientsByPrefix)`	Pass one Client and try multiple Clients explicitly
Legacy `mol` aliases	Their top-level `ccc` equivalents
Client `verbosity` and `withCycles` arguments	Remove the arguments
`NetworkPreference` and `preferredNetworks`	Select a fixed-network signer directly
Address recommendation `preference`	Remove the argument
Public JSON-RPC constructors	`.new({ transport })` or `.open({ urls })`
`Client.url`, `RequestorJsonRpc.url`, `ExecutorJsonRpc.url`	Retain endpoint configuration in the application

Epoch values

Use the Epoch class directly:

-const epoch = ccc.epochFrom(value);
-const decoded = ccc.epochFromHex(packed);
-const packed = ccc.epochToHex(epoch);
+const epoch = ccc.Epoch.from(value);
+const decoded = ccc.Epoch.fromNum(packed);
+const packed = ccc.Epoch.from(epoch).toPackedHex();

Replace array-style access with named properties:

-console.log(epoch[0], epoch[1], epoch[2]);
+console.log(epoch.integer, epoch.numerator, epoch.denominator);

Transaction helpers

Remove the At suffix from the compatibility methods:

-tx.setOutputDataAt(index, data);
-tx.getWitnessArgsAt(index);
-tx.getWitnessArgsAtUnsafe(index);
-tx.setWitnessArgsAt(index, witnessArgs);
-tx.setWitnessAt(index, witness);
+tx.setOutputData(index, data);
+tx.getWitnessArgs(index);
+tx.getWitnessArgsUnsafe(index);
+tx.setWitnessArgs(index, witnessArgs);
+tx.setWitness(index, witness);

Use the top-level serializer for JSON containing bigint values:

-const json = tx.stringify();
+const json = ccc.stringify(tx);

Address parsing

Address.fromString now accepts exactly one Client. Applications supporting more than one CKB network must choose or try Clients explicitly:

-const address = await ccc.Address.fromString(value, {
-  ckb: mainnetClient,
-  ckt: testnetClient,
-});
+let address: ccc.Address;
+try {
+  address = await ccc.Address.fromString(value, mainnetClient);
+} catch {
+  address = await ccc.Address.fromString(value, testnetClient);
+}

Molecule aliases

Move deprecated names out of the mol namespace. Molecule schema builders and predefined codecs such as mol.table, mol.vector, and mol.Uint32 remain in that namespace.

Before	After
`mol.Entity`	`ccc.Entity`
`mol.codec`	`ccc.codec`
`mol.Codec`	`ccc.Codec`
`mol.uint`	`ccc.codecUint`
`mol.uintNumber`	`ccc.codecUintNumber`
`mol.CodecLike`	`ccc.CodecLike`
`mol.DecodedType`	`ccc.DecodedType`
`mol.EncodableType`	`ccc.EncodableType`

Client block and header methods

The verbosity and withCycles arguments never affected requests. Remove them from calls and custom Client implementations:

-await client.getTipHeader(verbosity);
-await client.getBlockByNumber(number, verbosity, withCycles);
-await client.getBlockByHash(hash, verbosity, withCycles);
-await client.getHeaderByNumber(number, verbosity);
-await client.getHeaderByHash(hash, verbosity);
+await client.getTipHeader();
+await client.getBlockByNumber(number);
+await client.getBlockByHash(hash);
+await client.getHeaderByNumber(number);
+await client.getHeaderByHash(hash);

The corresponding NoCache methods use the same reduced signatures.

Wallet network selection

Wallet integrations now return one signer for each selectable network. NetworkPreference, preferredNetworks, and Signer.matchNetworkPreference() have been removed. Remove the preference configuration and select the desired returned signer instead.

-await controller.refresh(client, onUpdate, {
-  preferredNetworks: [{ addressPrefix: "ckt", signerType, network }],
-});
+await controller.refresh(client, onUpdate);

The optional arguments on getRecommendedAddress(preference) and getRecommendedAddressObj(preference) were also ignored:

-await signer.getRecommendedAddress(preference);
-await signer.getRecommendedAddressObj(preference);
+await signer.getRecommendedAddress();
+await signer.getRecommendedAddressObj();

For Connector ownership and component changes, also follow the Connector 2.0 migration guide.

JSON-RPC resource ownership

Use .new() when borrowing a Transport that another component owns. Use .open() when CCC should create the Transport, retain the returned Owner, and dispose it during final cleanup.

Public Clients

-const client = new ccc.ClientPublicTestnet();
+const clientOwner = ccc.ClientPublicTestnet.open();
+const client = clientOwner.value;
+// Final cleanup:
+await clientOwner.dispose();

Borrow an existing Transport without transferring ownership:

const client = ccc.ClientPublicTestnet.new({ transport });

WebSocket Transport

-const transport = new ccc.JsonRpcTransportWebSocket(url, timeout);
+const transportOwner = ccc.JsonRpcTransportWebSocket.open(url, timeout);
+const transport = transportOwner.value;
+// Final cleanup:
+await transportOwner.dispose();

Requestor

-const requestor = new ccc.RequestorJsonRpc(url, { fallbacks, timeout });
+const requestorOwner = ccc.RequestorJsonRpc.open({
+  urls: [url, ...fallbacks],
+  timeout,
+});
+const requestor = requestorOwner.value;
+// Final cleanup:
+await requestorOwner.dispose();

Use RequestorJsonRpc.new({ transport }) when borrowing a Transport.

SSRI Executor

-const executor = new ssri.ExecutorJsonRpc(url, { fallbacks, timeout });
+const executorOwner = ssri.ExecutorJsonRpc.open({
+  urls: [url, ...fallbacks],
+  timeout,
+});
+const executor = executorOwner.value;
+// Final cleanup:
+await executorOwner.dispose();

Use ExecutorJsonRpc.new({ transport }) when borrowing a Transport.

Endpoint configuration

Client.url, RequestorJsonRpc.url, and ExecutorJsonRpc.url have been removed because a Transport may have no URL or may use multiple fallback endpoints. Keep endpoint configuration separately when another library needs it:

const ckbUrls = ["https://testnet.ckb.dev/"] as const;
const clientOwner = ccc.ClientPublicTestnet.open({ urls: ckbUrls });

// Pass the explicitly retained endpoint to other libraries.
const indexer = new Indexer(ckbUrls[0]);

Dispose every Owner exactly once, after all borrowers have stopped using its value.

Migrate Removed Deprecated APIs

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