# Update a DID

The purpose of this document is to describe how an existing DID (and associated DIDDoc) can be *updated* using [the `cheqd-node` Cosmos CLI](https://docs.cheqd.io/node/getting-started/cheqd-cli).

> **NOTE: The procedures below are only recommended for development purposes!**
>
> Using `cheqd-node` Cosmos CLI for real-world production usage is not recommended, since the identity keys are passed in raw form to the CLI. This is fine in development/testing usage, but is not recommend for mainnet.
>
> Developers are encouraged to use [production-grade CLI tools such as Veramo SDK for cheqd](https://docs.cheqd.io/product/sdk/veramo) or look at [our developer guide on how to integrate custom applications](https://docs.cheqd.io/product/advanced/tooling/advanced).

## Setup

### Pre-Requisites

* Learn how to [create a DID with cheqd Cosmos CLI](https://docs.cheqd.io/product/advanced/tooling/cheqd-node-cli/create-did)
* [Query an existing DID/DIDDoc](https://docs.cheqd.io/product/advanced/tooling/cheqd-node-cli/query-did) with cheqd Cosmos CLI

### Assumptions

* Given this procedure below is intended for development/training purposes, we assume that the user stores their public/private keys safely during the DID creation process and has access to it.
* Updating a DIDDoc requires the *full* updated DIDDoc to be sent. Only the updated/changed parts cannot be sent. This accounts for scenarios where the DIDDoc may have been updated on ledger, but the local copy is not synced with the latest changes.

## Update an existing DID

### 1. Update the DIDDoc contents / body

Use a text editor like `nano` to edit the body of the DIDDoc (the example below assumes it's saved in a file called `payload.json`).

```bash
nano payload.json
```

For example, we can [take the DIDDoc created previously](https://docs.cheqd.io/product/advanced/tooling/cheqd-node-cli/create-did) and change the Service Endpoint from `bar.example.com` to `foo.example.com`:

```json
{
  "id": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77",
  "verificationMethod": [
    {
      "id": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#key1",
      "type": "Ed25519VerificationKey2018",
      "controller": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77",
      "publicKeyBase58": "4Q41kvWsd1JAuPFBff8Dti7P6fLbPZe3Nmod35uua9TE"
    }
  ],
  "authentication": [
    "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#key1"
  ],
  "service": [{
    "id":"did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#linked-domain",
    "type": "LinkedDomains",
    "serviceEndpoint": [
      "https://foo.example.com"
    ]
  }]
}
```

### 2. Compile the payload

As in flow with [creating DID-Document](https://docs.cheqd.io/product/advanced/tooling/cheqd-node-cli/create-did) we need to compile `payload.json` file with private key inside and pass it to the CLI. The result JSON in our example will look liks:

```json
{
  "payload": {
    "id": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77",
    "verificationMethod": [
      {
        "id": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#key1",
        "type": "Ed25519VerificationKey2018",
        "controller": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77",
        "publicKeyBase58": "4Q41kvWsd1JAuPFBff8Dti7P6fLbPZe3Nmod35uua9TE"
      }
    ],
    "authentication": [
      "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#key1"
    ],
    "service": [{
      "id":"did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#linked-domain",
      "type": "LinkedDomains",
      "serviceEndpoint": [
        "https://foo.example.com"
      ]
    }]
  },
  "signInputs": [
    {
      "verificationMethodId": "did:cheqd:testnet:b0ca0b75-ca6a-4674-a261-45f6dd0c9c77#key1",
      "privKey": "wNXCJ9Ny0uzCYhnTE3gfQuwgQM4QZCw08+j01QDfoGxMMI9u9GIv/90eH3E3KjHjlSi9hKRQy94PvKVAH1+Rhw=="
    }
  ]
}
```

### 3. Send an update DID transaction to the ledger

Send the updated DIDDoc to the ledger. This *must* be signed with the correct identity keys:

```bash
cheqd-noded tx cheqd update-did <Payload_in_JSON>  \
  --from <cosmos_account> --node <url> --chain-id <chain> --fees <fee>
```

### Flags

* `Payload_in_JSON` - previously compiled JSON.
* `--from`: Cosmos account key which will pay fees for the transaction to be written to ledger.
* `--node`: IP address or URL of node to send request to
* `--chain-id`: E.g., `cheqd-testnet-6`
* `--fees`: Set to 25000000000ncheq, which is the fixed fee for updating a DID

> Note that each of cheqd's on-ledger identity transactions has a **fixed fee,** [the pricing for cheqd DIDs and DID-Linked Resources can be found here](https://docs.cheqd.io/node/architecture/adr-list/adr-005-genesis-parameters#cheqd-module-did-module). If your account has insufficient balance the transaction will fail.

### Example

```bash
cheqd-noded tx cheqd update-did "payload.json" \
  --from my_account --node http://rpc.cheqd.network:443 --chain-id cheqd-testnet-6 --fees 25000000000ncheq
```