> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/tempo/consensus_getidentitytransitionproof-tempo.md).

# consensus\_getIdentityTransitionProof - Tempo

Example code for the consensus\_getIdentityTransitionProof JSON-RPC method. Complete guide on how to use consensus\_getIdentityTransitionProof JSON-RPC in GetBlock Web3 documentation.

Returns DKG (Distributed Key Generation) identity transition proofs. Used by light clients and bridges to verify validator set transitions across epochs. By default returns only the most recent transition; pass `full=true` to walk all transitions back to genesis.

{% hint style="warning" %}
**VALIDATOR-NODE-ONLY METHOD.** This method is part of the `consensus_*` namespace and is only available on Tempo validator nodes. It is **not** available on shared RPC infrastructure such as GetBlock's standard shared endpoints. Calling this method against a non-validator node returns `-32601 Method not found`. If you need access, contact GetBlock for dedicated validator node access.
{% endhint %}

## Parameters

| Parameter   | Type            | Required | Description                                                                                           |
| ----------- | --------------- | -------- | ----------------------------------------------------------------------------------------------------- |
| from\_epoch | integer or null | No       | Epoch to search from (defaults to latest finalized)                                                   |
| full        | boolean or null | No       | If `true`, return all transitions back to genesis; if `false` or null (default), only the most recent |

## Request Example

{% tabs %}
{% tab title="cURL" %}

```bash
curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "consensus_getIdentityTransitionProof",
    "params": [
        null,
        null
    ],
    "id": "getblock.io"
}'
```

{% endtab %}

{% tab title="JavaScript (Axios)" %}

```javascript
import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "consensus_getIdentityTransitionProof",
    "params": [
        null,
        null
    ],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));
```

{% endtab %}

{% tab title="Python (Requests)" %}

```python
import requests
import json

url = "https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "consensus_getIdentityTransitionProof",
    "params": [
        null,
        null
    ],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)
```

{% endtab %}

{% tab title="Rust (Reqwest)" %}

```rust
use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "consensus_getIdentityTransitionProof",
        "params": [
                null,
                null
        ],
        "id": "getblock.io"
});

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}
```

{% endtab %}
{% endtabs %}

## Response Example

{% code overflow="wrap" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "identity": "0x8e1aa0e2d4c7f9d4b0c8b8d5f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4",
        "transitions": [
            {
                "transitionEpoch": 42,
                "oldIdentity": "0x7d4c2e0f1a3b5c7d9e1f2a4b6c8d0e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3",
                "newIdentity": "0x8e1aa0e2d4c7f9d4b0c8b8d5f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4",
                "proof": {
                    "header": {
                        "number": "0x9c40",
                        "hash": "0x6baa8fa86b9a7e5d3f1c8a4b6e9d2f5a8c3e7b1d4f9a6c2e5b8d3f7a1c4e9b2d"
                    },
                    "certificate": "0xc4b5a6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6"
                }
            }
        ]
    }
}
```

{% endcode %}

## Response Parameters

| Field                                 | Type                        | Description                                                            |
| ------------------------------------- | --------------------------- | ---------------------------------------------------------------------- |
| result.identity                       | string                      | Hex-encoded BLS public key at the requested epoch                      |
| result.transitions                    | array of IdentityTransition | Transitions ordered newest to oldest                                   |
| result.transitions\[].transitionEpoch | integer                     | Epoch where the DKG ceremony occurred                                  |
| result.transitions\[].oldIdentity     | string                      | BLS public key before the transition                                   |
| result.transitions\[].newIdentity     | string                      | BLS public key after the transition                                    |
| result.transitions\[].proof           | object                      | Block header + finalization certificate. Omitted for genesis (epoch 0) |

## Use Cases

* Light client validator-set verification across epochs
* Cross-chain bridges proving Tempo validator transitions
* Audit tools verifying DKG ceremony integrity

## Error Handling

| Status Code | Error Message     | Cause                                                        |
| ----------- | ----------------- | ------------------------------------------------------------ |
| 403         | Forbidden         | Missing or invalid `<ACCESS-TOKEN>`                          |
| -32602      | Invalid params    | Request parameters are missing or malformed                  |
| -32601      | Method not found  | Method does not exist or is not enabled on this node         |
| 429         | Too Many Requests | Rate limit exceeded for your plan                            |
| -32601      | Method not found  | Validator-only method — not exposed on shared infrastructure |

## SDK Integration

{% tabs %}
{% tab title="JavaScript (Axios)" %}

```javascript
import axios from 'axios';

const response = await axios.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    id: 'getblock.io',
    method: 'consensus_getIdentityTransitionProof',
    params: [null, null]
}});
console.log(response.data);
```

{% endtab %}

{% tab title="Python (Requests)" %}

```python
import requests

response = requests.post('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', json={
    'jsonrpc': '2.0',
    'id': 'getblock.io',
    'method': 'consensus_getIdentityTransitionProof',
    'params': [null, null]
}})
print(response.json())
```

{% endtab %}
{% endtabs %}