COTI TypeScript SDK for PoD

Package: @coti-io/coti-sdk-typescript

This is the low-level cryptography layer beneath @coti/pod-sdk. Use it when you need signed it* payload construction, account key recovery, or direct decrypt helpers. Most PoD apps call CotiPodCrypto instead, which delegates decrypt to this package.

npm install @coti-io/coti-sdk-typescript

APIs commonly used with PoD

API	Purpose
buildInputText	Build signed encrypted numeric input payload
buildStringInputText	Build signed encrypted string input payload
decryptUint / decryptUint256	Decrypt numeric ciphertext with account AES key
decryptString	Decrypt string ciphertext with account AES key
generateRSAKeyPair	Generate onboarding RSA keys
recoverUserKey	Reconstruct account AES key from encrypted shares

See Account onboarding (AES key) for the recovery flow.

Safer selector handling

Avoid hardcoding function selectors. Build from the contract ABI:

import { Interface, Wallet } from "ethers";
import { buildInputText } from "@coti-io/coti-sdk-typescript";

const iface = new Interface(["function compare((uint256,bytes),(uint256,bytes))"]);
const selector = iface.getFunction("compare")!.selector;

const sender = {
  wallet: new Wallet(process.env.PRIVATE_KEY!),
  userKey: accountAesKey,
};

const itValue = buildInputText(42n, sender, contractAddress, selector);

The contractAddress and selector used when signing must match the on-chain call target exactly.

String input example

import { buildStringInputText } from "@coti-io/coti-sdk-typescript";

const itMemo = buildStringInputText("private memo", sender, contractAddress, selector);

Decryption example

import { decryptUint, decryptString } from "@coti-io/coti-sdk-typescript";

const amount = decryptUint(BigInt(ctAmountHex), accountAesKey);
const note = decryptString({ value: ctStringCells }, accountAesKey);

For ctUint256 limbs, prefer decryptUint256({ ciphertextHigh, ciphertextLow }, accountAesKey) (see Reference: data types).

Relationship to @coti/pod-sdk

Task	Package
Encrypt plaintext via PoD encryption HTTP service	@coti/pod-sdk (CotiPodCrypto.encrypt)
Decrypt ct* in app code	@coti/pod-sdk (CotiPodCrypto.decrypt) or this package directly
Onboard user / recover AES key	This package
Fee estimate, submit tx, track request	@coti/pod-sdk (PodContract, PodRequest)

See also

• Account onboarding (AES key)

• TypeScript PoD SDK