> For the complete documentation index, see [llms.txt](https://fifo-docs.gitbook.io/colibri/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://fifo-docs.gitbook.io/colibri/colibri-core/strkeys.md).

# StrKeys

StrKeys encode Stellar keys and identifiers with a type prefix. Core adds branded TypeScript types and two distinct levels of validation.

## Encoding and decoding

Both [`@colibri/core`](/colibri/colibri-core/overview.md) and the lightweight `@colibri/core/strkey` entrypoint expose the same `StrKey` object. Its encode/decode helpers preserve the Stellar SDK's accepted arguments. Encoders return the corresponding Colibri prefix type; decoders return the SDK's byte representation.

```ts
import { StrKey } from "@colibri/core/strkey";
import type { ContractId } from "@colibri/core";

const bytes = new Uint8Array(32);
const contractId: ContractId = StrKey.encodeContract(bytes);
const decoded = StrKey.decodeContract(contractId);
console.log(contractId, decoded.length);
```

For npm TypeScript consumers, use Core **1.1.1 or later**: this restores the encoding/decoding declarations omitted from the 1.1.0 npm distribution. Runtime encoding behavior is unchanged. See the [StrKey API](https://jsr.io/@colibri/core/doc/strkey) for all helpers.

## Format guards versus checksum validation

| Purpose                     | Examples                                                                                      | What it establishes                                      |
| --------------------------- | --------------------------------------------------------------------------------------------- | -------------------------------------------------------- |
| Quick format/type narrowing | `isEd25519PublicKey`, `isContractId`, `isMuxedAddress`                                        | Prefix, alphabet, and length; **not** checksum validity  |
| Format plus checksum        | `isValidEd25519PublicKey`, `isValidContractId`, `isValidMuxedAddress`                         | Structurally valid encoded value; not on-chain existence |
| Other encoded kinds         | `isPreAuthTx`, `isSha256Hash`, `isSignedPayload`, `isLiquidityPoolId`, `isClaimableBalanceId` | The documented format guard for that kind                |

Checksum-aware variants also exist for secret seeds, signed payloads, liquidity pools, and claimable balances. Use the [API reference](https://jsr.io/@colibri/core/doc) for the exact names; for example, the secret-seed validator is `isValidEd25519SecretSeed`, while its format guard is `isEd25519SecretKey`.

## Validate application input

Install Core and run this complete local script with `deno run address.ts`. There is no network request.

```ts
import { NativeAccount, StrKey } from "@colibri/core";

const input = "GALAXYVOIDAOPZTDLHILAJQKCVVFMD4IKLXLSZV5YHO7VY74IWZILUTO";
if (StrKey.isValidEd25519PublicKey(input)) {
  // The guard both checks the checksum and narrows input's type.
  const account = NativeAccount.fromAddress(input);
  console.log(account.address());
} else {
  console.error("Expected a checksummed Stellar G-address");
}
```

A format guard may accept a key whose checksum is wrong. Neither level proves that an account is funded, that a contract is deployed, or that the user controls a private key. Read the network or perform the relevant authorization separately.

Do not infer address ownership from its prefix, and never log an input that may contain a secret seed. For muxed-account normalization and embedded IDs, see [address helpers](/colibri/colibri-core/address.md). For exact signer keys in transaction preconditions, see [signers](/colibri/colibri-core/signer.md).