> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hyperauth.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# POST /api/dids

> Registers a new decentralized identifier (DID) on-chain after the user's identifier has been verified via OTP, completing the HyperAuth signup flow.

Registers a DID after the identifier has been verified. For non-handle channels, an `attestation` object must be present and is validated against the `ATTESTATION_SIGNING_KEY` before the DO call is made.

## Request body

| Field          | Type                      | Required | Description                                               |
| -------------- | ------------------------- | -------- | --------------------------------------------------------- |
| `credentialId` | `string`                  | Yes      | WebAuthn credential ID                                    |
| `identifier`   | `string`                  | Yes      | Registration identifier (also accepts `handle` or `name`) |
| `channel`      | `string`                  | Yes      | Channel type                                              |
| `did`          | `string`                  | Yes      | DID to register                                           |
| `txHash`       | `string`                  | Yes      | Transaction hash of the on-chain registration             |
| `blockNumber`  | `number`                  | No       | Block number of the transaction                           |
| `smartAccount` | `string`                  | No       | Smart account address                                     |
| `attestation`  | `VerificationAttestation` | No       | Required for non-handle channels                          |

## Response (200)

```json theme={null}
{ "ok": true, "identifier": "alice", "channel": "handle", "txHash": "0x..." }
```

## Errors

| Code  | `error`                                                                     | Condition                                             |
| ----- | --------------------------------------------------------------------------- | ----------------------------------------------------- |
| `400` | `"Missing required fields: credentialId, identifier, channel, did, txHash"` | Field absent                                          |
| `403` | `"attestation_invalid"`                                                     | Attestation signature invalid                         |
| `403` | `"attestation_mismatch"`                                                    | Attestation identifier/channel does not match request |
| `409` | `"credential_already_registered"`                                           | Credential ID already in `registered_dids`            |