Sentinel API Reference

The Sentinel API allows you to programmatically create and manage sentinels.

Requests need to be authenticated with a bearer token, which is negotiated from the Team API Key with the corresponding capability. Refer to the authentication section for info on how to negotiate it.

We recommend you use the defender-sentinel-client npm package for simplifying interactions with the Sentinel API.

const { SentinelClient } = require('defender-sentinel-client');
const creds = { apiKey: ADMIN_API_KEY, apiSecret: ADMIN_API_SECRET };
const client = new SentinelClient(creds);

Notifications Endpoint

A sentinel requires a notification configuration to alert the right channels in case an event is triggered. In order to do so, you can either use an existing notification ID (from another sentinel for example), or create a new one.

The following notification channels are available:

email
slack
discord
telegram
datadog

The createNotificationChannel function requires the NotificationType and NotificationRequest parameters respectively, and returns a NotificationResponse object.

// List existing notification channels
// This returns a `NotificationResponse[]` object.
const notificationChannels = await client.listNotificationChannels()
const { notificationId, type } = notificationChannels[0];

// create a new notification
const notification = await client.createNotificationChannel('email', {
  name: 'MyEmailNotification',
  config: {
    emails: ['john@example.com'],
  },
  paused: false,
});

const notification = await client.createNotificationChannel('slack', {
  name: 'MySlackNotification',
  config: {
    url: 'https://slack.com/url/key',
  },
  paused: false,
});

const notification = await client.createNotificationChannel('telegram', {
  name: 'MyTelegramNotification',
  config: {
    botToken: 'abcd',
    chatId: '123',
  },
  paused: false,
});

const notification = await client.createNotificationChannel('discord', {
  name: 'MyDiscordNotification',
  config: {
    url: 'https://discord.com/url/key',
  },
  paused: false,
});

const notification = await client.createNotificationChannel('datadog', {
  name: 'MyDatadogNotification',
  config: {
    apiKey: 'abcd',
    metricPrefix: 'prefix',
  },
  paused: false,
});

The notifications endpoint is used to retrieve a list of existing notification channels via a GET request.

curl \
  -X GET \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
    "https://defender-api.openzeppelin.com/notifications"

An example response:

[
    {
        "notificationId": "14e99e8f-e2be-4eb1-a543-b2d90b68cdd8",
        "config": {
            "emails": [
                "john@example.com"
            ]
        },
        "updatedAt": "2021-11-04T12:21:22.858Z",
        "tenantId": "0c1585a9-1b86-4f9d-8468-28227802ac1d",
        "paused": false,
        "name": "MyEmailNotification",
        "type": "email"
    },
]

Sentinels Endpoint

List Sentinels

To list existing sentinels, you can call the list function on the client, which returns a CreateSentinelResponse[] object:

await client.list();

The subscribers endpoint is used to retrieve a list of existing sentinels via a GET request.

curl \
  -X GET \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
    "https://defender-api.openzeppelin.com/subscribers"

An example response:

[
    {
        "notifyConfig": {
            "notifications": [
                {
                    "type": "email",
                    "notificationId": "68e494d7-3b5a-4ffe-bd12-d4e483aa4995"
                }
            ],
            "timeoutMs": 0
        },
        "tenantId": "0c1585a9-1b86-4f9d-8468-28227802ac1d",
        "createdAt": "2021-11-15T16:04:13.936Z",
        "addressRules": [
            {
                "conditions": [],
                "abi": "[...]",
                "address": "0xf664FA8aB9AA8021E2c08F45fEeA817D5730A713"
            }
        ],
        "blockWatcherId": "rinkeby-1",
        "subscriberId": "abebeda6-f670-4e3c-a65b-a34c840e9a5e",
        "paused": false,
        "name": "test",
        "network": "rinkeby"
    }
]

Create Sentinels

To create a new sentinel, you need to provide the network, name, pause-state, conditions, alert threshold and notification configuration. This request is exported as type CreateSentinelRequest.

interface CreateSentinelRequest {
  network: string;
  confirmLevel?: number;
  name: string;
  address: string;
  abi?: string;
  paused?: boolean;
  eventConditions?: EventCondition[];
  functionConditions?: FunctionCondition[]
  txCondition?: string;
  autotaskCondition?: string;
  autotaskTrigger?: string;
  alertThreshold?: Threshold;
  alertTimeoutMs?: number;
  notificationChannels: string[];
}

An example is provided below. This sentinel will be named My New Sentinel and will be monitoring the renounceOwnership function on the 0x0f06aB75c7DD497981b75CD82F6566e3a5CAd8f2 contract on the Rinkeby network. The alert threshold is set to 2 times within 1 hour, and the user will be notified via email.

const requestParameters = {
  network: 'rinkeby',
  // optional
  confirmLevel: 1, // if not set, we pick the blockwatcher for the chosen network with the lowest offset
  name: 'My New Sentinel',
  address: '0x0f06aB75c7DD497981b75CD82F6566e3a5CAd8f2',
  abi: '[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{...}]',
  // optional
  paused: false,
  // optional
  eventConditions: [],
  // optional
  functionConditions: [{ functionSignature: 'renounceOwnership()' }],
  // optional
  txCondition: 'gasPrice > 0',
  // optional
  autotaskCondition: '3dcfee82-f5bd-43e3-8480-0676e5c28964',
  // optional
  autotaskTrigger: undefined,
  // optional
  alertThreshold: {
    amount: 2,
    windowSeconds: 3600,
  },
  // optional
  alertTimeoutMs: 0,
  notificationChannels: [notification.notificationId],
};

Once all required parameters are populated, you can create a sentinel by calling the create function on the client. This will return a CreateSentinelResponse object.

await client.create(requestParameters);

If you wish to trigger the sentinel based on additional events, you could add another EventCondition or FunctionCondition object, for example:

functionConditions: [{ functionSignature: 'renounceOwnership()' }],
eventConditions: [
  {
    eventSignature: "OwnershipTransferred(address,address)",
    expression: "\"0xf5453Ac1b5A978024F0469ea36Be25887EA812b5,0x6B9501462d48F7e78Ba11c98508ee16d29a03412\""
  }
]

You could also apply a transaction condition by modifying the txCondition property: Possible variables: value, gasPrice, gasUsed, to, from, nonce, status ('success', 'failed' or 'any'), input, or transactionIndex.

txCondition: 'gasPrice > 0',

Additionally, the sentinel could invoke an autotask to further evaluate. Documentation around this can be found here: https://docs.openzeppelin.com/defender/sentinel#autotask_conditions.

// If other conditions match, the sentinel will invoke this autotask to further evaluate.
autotaskCondition: '3dcfee82-f5bd-43e3-8480-0676e5c28964',
// Define autotask within the notification configuration
autotaskTrigger: '1abfee11-a5bc-51e5-1180-0675a5b24c61',

The subscribers endpoint is used to a create new sentinels via a POST request. If you wish to call the API directly, you will need to construct a CreateBlockSubscriberRequest object.

Defender currently only supports a limited subset of Sentinels (only a single addressRule), and we strongly suggest going through the JS client to avoid incompatibilities.

interface CreateBlockSubscriberRequest {
  name: string;
  paused: boolean;
  alertThreshold?: {
    amount: number;
    windowSeconds: number;
  };
  notifyConfig?: {
    notifications: [{
      notificationId: string;
      type: NotificationType;
    }];
    autotaskId?: string;
    timeoutMs: number;
  };
  addressRules: [{
    conditions: ConditionSet[];
    autotaskCondition?: {
      autotaskId: string;
    };
    address: string;
    abi?: string;
  }];
  blockWatcherId: string;
  network: Network;
  type: 'BLOCK';
}

type NotificationType = 'slack' | 'email' | 'discord' | 'telegram' | 'datadog';

interface ConditionSet {
  eventConditions: EventCondition[];
  txConditions: TxCondition[];
  functionConditions: FunctionCondition[];
}
interface EventCondition {
  eventSignature: string;
  expression?: string | null;
}
interface TxCondition {
  status: 'success' | 'failed' | 'any';
  expression?: string | null;
}
interface FunctionCondition {
  functionSignature: string;
  expression?: string | null;
}

curl \
  -X POST \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{...}' \
    "https://defender-api.openzeppelin.com/subscribers"

Retrieve a Sentinel

You can retrieve a sentinel by ID. This will return a CreateSentinelResponse object.

await client.get('8181d9e0-88ce-4db0-802a-2b56e2e6a7b1');

The subscribers/{id} endpoint is used to retrieve a sentinel via a GET request.

curl \
  -X GET \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
    "https://defender-api.openzeppelin.com/subscribers/{id}"

Update a Sentinel

To update a sentinel, you can call the update function on the client. This will require the sentinel ID and a CreateSentinelRequest object as parameters:

await client.update('8181d9e0-88ce-4db0-802a-2b56e2e6a7b1', requestParameters);

The subscribers/{id} endpoint is used to a update existing sentinels via a PUT request.

If you wish to call the API directly, you will need to construct a CreateBlockSubscriberRequest object.

curl \
  -X PUT \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{...}' \
    "https://defender-api.openzeppelin.com/subscribers/{id}"

Delete a Sentinel

You can delete a sentinel by ID. This will return a DeletedSentinelResponse object.

await client.delete('8181d9e0-88ce-4db0-802a-2b56e2e6a7b1');

The subscribers/{id} endpoint is used to a delete a sentinel via a DELETE request.

curl \
  -X DELETE \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H "X-Api-Key: $KEY" \
  -H "Authorization: Bearer $TOKEN" \
    "https://defender-api.openzeppelin.com/subscribers/{id}"

An example response:

{
    "message": "subscriber deleted"
}

Pause or unpause a Sentinel

You can pause and unpause a sentinel by ID. This will return a CreateSentinelResponse object.

await client.pause('8181d9e0-88ce-4db0-802a-2b56e2e6a7b1');
await client.unpause('8181d9e0-88ce-4db0-802a-2b56e2e6a7b1');

If you wish to call the API directly, you can use the update endpoint and set pause to true or false accordingly.