SDK (@caplane/shared)

@caplane/shared is the order encoding, signing, and registry layer the consumer agent, the relayer, and the el-proxy share. It is the convenience layer; the encoding spec is the contract. You can reimplement the encoding in any language and still be correct. The groups below mirror the package’s index.ts exports. The @caplane/consumer-agent conveniences (the connect() on-ramp) are listed at the end.

Order and hashing

Export	Signature	Purpose
`Order`	`interface`	The 8-field order. See the Order struct.
`ORDER_TUPLE`	`const`	The ABI tuple mirroring `Order` field order and types.
`encodeOrder`	`(order: Order) => Hex`	`abi.encode(order)` via viem’s `encodeAbiParameters`.
`orderHash`	`(order: Order) => Hex`	`keccak256(encodeOrder(order))`, the EIP-3009 nonce.

Signing

Export	Signature	Purpose
`TRANSFER_WITH_AUTHORIZATION`	`const`	The EIP-3009 typed-data schema (`nonce` is `bytes32`).
`buildTransferAuthorization`	`(domain, order, broker, validAfter, validBefore) => TransferAuthorization`	The unsigned authorization (pure; testable against a golden digest).
`transferAuthDigest`	`(auth: TransferAuthorization) => Hex`	The EIP-712 digest the token verifies.
`signOrder`	`(account, domain, order, broker, validAfter, validBefore) => Promise<SignedAuthorization>`	Sign the authorization with `nonce = orderHash`. Returns `{ v, r, s, validAfter, validBefore, orderHash }`.
`SignedAuthorization`	`interface`	The split signature plus the window and the bound `orderHash`.

Wire and relayer types

Export	Signature	Purpose
`orderToJson`	`(order: Order) => OrderJson`	Serialize an order to its wire shape (uint256 as decimal strings).
`orderFromJson`	`(json: OrderJson) => Order`	Parse an order from its wire shape.
`RELAY_ERROR_STATUS`	`Record<RelayErrorCode, number>`	The code to HTTP status map.
`RelayRequest`	`interface`	The `POST /broker` body.
`RelaySuccess`	`interface`	The `200` response (`ok`, `txHash`, `orderHash`, `brokered`, `receipt`, `feeCollected`).
`RelayFailure`	`interface`	The error response (`ok: false`, `code`, `message`). Carries no key material.
`RelayResponse`	`type`	The union `RelaySuccess` or `RelayFailure`.
`RelayErrorCode`	`type`	The seven settlement error codes. See errors.
`RelayerInfo`	`interface`	The `GET /info` body (`feeFloorBps`, `supportedChainIds`, `relayer`).
`OrderJson`	`interface`	The order’s JSON wire shape.

Registry and discovery

Addresses are never hard-coded. They are read from the registry, which is the single trust root.

Export	Signature	Purpose
`loadRegistry`	`(chainId, opts?) => Registry`	Load a chain’s registry (contracts, USDC domain, rpcUrl, explorer).
`loadChain`	`(chainId, opts?) => Registry`	Alias used by `connect()`.
`resolveDeploymentsDir`	`(opts?) => string`	Resolve the deployments directory.
`resolveCapability`	`(name, opts?) => ResolvedCapability`	Resolve a capability to its chain and adapter address. Fails closed on an unknown capability.
`listCapabilities`	`(opts?) => string[]`	The capability names available.
`loadCapabilities`	`(opts?) => CapabilitiesFile`	Parse `capabilities.json`.
`domainFromRegistry`	`(registry) => Eip712Domain`	Build the USDC EIP-712 domain.
`CHAIN_IDS`	`const`	`{ arbitrumSepolia: 421614, robinhoodTestnet: 46630 }`.
`REGISTRY_FILES`	`const`	The registry file names per chain.
`Registry`, `RegistryUsdc`, `RegistryTimeboost`, `Eip712Domain`, `CapabilitySpec`, `ResolvedCapability`	types	The registry and capability shapes.

Attestation (for the AttestedAdapter)

The optional provider attestation surface, used by the AttestedAdapter. Exports: ATTESTATION_TYPES, ATTESTOR_DOMAIN_NAME, ATTESTOR_DOMAIN_VERSION, OFFCHAIN_VERIFYING_CONTRACT, buildAttestation, attestationDigest, signAttestation, recoverAttestor, verifyAttestation, encodeAttestedParams, paramsSubject, and the Attestation / AttestorDomain types. These build, sign, and verify the EIP-712 attestation an AttestedAdapter checks at grant time.

Consumer conveniences (@caplane/consumer-agent)

The on-ramp over the surface above. Documented end to end in broker a capability.

Export	Signature	Purpose
`connect`	`(opts: ConnectOptions) => Promise<CaplaneClient>`	Registry-bound, key-free client. Exposes `buyAllocation` and the generic `broker`.
`discover`	`(publicClient, adapter, params) => Promise<Quote>`	Read `adapter.quote(params)` for `{ price, payToken }`.
`buildOrder`	`(args: BuildOrderArgs) => Order`	Assemble an order; `nonce` defaults to a random salt.
`randomNonce`	`() => bigint`	A random 256-bit salt for `order.nonce`.
`submit`	`(relayerUrl, order, sig, chainId, opts?) => Promise<RelaySuccess>`	POST the signed order; throws `SubmitError(code)` on rejection.
`SubmitError`	`class`	A typed submit failure carrying the `RelayErrorCode`.
`encodeAllocationParams`	`(vaultId: bigint) => Hex`	`abi.encode(uint256 vaultId)` for the Allocation adapter.
`decodeAllocationReceipt`	`(receipt: Hex) => bigint`	Decode an Allocation grant receipt to the minted slot id.

​Order and hashing

​Signing

​Wire and relayer types

​Registry and discovery

​Attestation (for the AttestedAdapter)

​Consumer conveniences (@caplane/consumer-agent)

​See also