Mempool Explorer
Mempool Explorer™ lets you go hands-on with real-time Ethereum data. Watch addresses, filter and select events, and determine what data you want to build with.


This documentation describes how to use Blocknative’s Mempool Explorer. Mempool Explorer enables you to create data feeds for the addresses (wallet or contract) that you care about. Add filters and push your feed into a webhook that you can start building with.
Mempool Explorer uses our API, which has rate limits. Please see Rate Limits for more details.

Getting Started

Create Your Feed

  1. 1.
    Go to to begin creating your feed.
  2. 2.
    Create a subscription by filling the new subscription card. Enter an address or select a quick start.
Enter an address or select a quick start
3. Select the network you want to monitor for the subscribed address
Network selector
Select a network
4. Click Create and Mempool Explorer will subscribe to all transactions that involve that address. You will see events appear on the panel on the right as new transactions occur:
Sample event

Creating Subscriptions

Subscriptions enable you to monitor any smart contract or wallet address.
When you land on Mempool Explorer, an empty Create New Subscription card will be waiting for you to fill.
Create a new subscription
Enter a valid Ethereum address or ENS name to start subscribing to events, or alternatively you can select a quick start option from the dropdown to watch common contract addresses.
Select from most watched addresses
Once you have a subscription created, you can optionally rename it, add an ABI to decode input data or delete it via the subscription menu. To display the menu, click the ellipsis in the top right corner.
Open the subscription menu
Rename the subscription


See how to get started with Mempool Explorer in this screencast:
Introductory Walk Through of Mempool Explorer
Add local ABI to interpret and filter transaction data in this screencast:
Custom ABIs with Mempool Explorer
Compose subscriptions for external services with webhooks in this screencast:
Compose with Webhooks in Mempool Explorer


Once a subscription has been created, Mempool Explorer will display an event for every transaction that involves that address. You may want to limit displayed events to transactions that fit a particular criteria and to do this you can create filters to apply to each event.
Click the Global Filter button to start creating a Global Filter. Global Filters filter all of your subscriptions and will contain selectable properties that apply to all subscription events. If you would like to filter on a property that only exists on a particular contract address, then use a local filter scoped to that subscription.
You will see the filter form modal appear:
Global filter form
You can then traverse the event object schema to select the properties that you would like to create a comparison that any new events must pass before being displayed:
Traversing the object event schema 🧗
The type of comparison that is used to create a filter depends on the parameter that is selected. The following is a complete list of the comparisons that can be made:


Used to check that a property value is not undefined (that is to say is defined).


Used to match string values and tests for an exact match.


Used to match string values that are not the value that has been inputted.


Used to select a list of possible string values, where if there is a match on any one of them then the comparison has passed.

greater than

Used to compare numerical values against an inputted value

greater than or equal to

Used to compare numerical values against an inputted value

less than

Used to compare numerical values against an inputted value

less than or equal to

Used to compare numerical values against an inputted value
Once you are happy with your filter comparison, click the "Add" button to add it to the list of filters that are being applied.


Blocknative transaction events are very detailed and contain a lot of data, all of which you might need. If you would like to reduce the amount of data delivered in events to only key information, then you can Select the information you need to do just that!
Click the Global Filter button to start filling a Select Form and you will see it appear within a modal. Global Select affects all of your subscriptions.
Global select form
You can then traverse the notification object schema to select the properties that you would like to be included in the event:
Selecting properties to be displayed in the event payload
Once you have settled on a property that you want to include in the event, click the "add" button which will add it to your Select list include.
By default every property is selected with the event. As soon as you Select any property, the event will start displaying only the properties selected.

Global vs Local

You can Filter and Select globally for all of your subscriptions or locally for each subscription. This allows for ease of use and flexibility in how you modify displayed events.
A Global Filter or Select applies to all of your subscriptions and is located at the top of your subscriptions:
Global controls at the top
A local Filter or Select applies only to the subscription they are added to and are located on the subscription card:
Subscription filters and selectors at the bottom of the card
A Global Filter/Select applies to all transactions/addresses watched. Therefore a Global Filter only supports generic transaction fields. A Local Filter/Select applies to an address can include fields, such as methodName,that are specific to the contract at that address. Local Filters/Selects can use fields defined in the contract ABI (if uploaded in the subscription or one of the default ABIs already supported).

Contract ABI

If the address you are creating a subscription for is a contract address, then you can upload the ABI for that contract and Mempool Explorer will automatically decode the input data for any contract calls for that address.
You can upload a .json file of the ABI by clicking the ABI button on the subscription card:
The ABI button located on the subscription card (Neutral State)
The ABI button has four (4) total states:
  • Neutral, indicating no ABI is detected.
  • Green, indicating a working ABI has been detected or uploaded and contract events are being decoded successfully.
  • Yellow, indicating the ABI uploaded may be incorrect for that contract address. This status is shown after 10 or more events have failed to decode successfully.
  • Red, indicating the uploaded ABI is an invalid object.
Sample ABI State (Red)
If the uploaded ABI for the contract is invalid, Mempool Explorer will change the ABI indicator to Yellow and send a notification indicating the ABI provided has failed to decode the input after 10 events related to that contract address:
Sample Invalid ABI Notification
Blocknative backend infrastructure automatically decodes contract input data for common ERC20 and ERC721 tokens and other popular contracts, so there is no need to upload an ABI for these contract types. For a full list head to the API Docs.

Configurations Sidebar

A Configuration is a set of Mempool Explorer subscriptions for a specific network. You can choose to save a configuration to an API key or load one from an API key. Note that for each network, there can be a different configuration saved to the same API key. To be able to save and load configurations, you will need to log in to your Blocknative account.

Setup Configuration

  1. 1.
    Create a Blocknative account by clicking the Login button on Mempool Explorer and following the instructions. Account creation requires email confirmation to complete.
  2. 2.
    Blocknative will create a Default API key for your account that you can save your configuration to. You can create additional API keys from your account dashboard on or from the Create New API Key on the Save configuration flow.
Once you have an account, you can login to Mempool Explorer by clicking the Login button at the top right. This will activate your Configurations Sidebar to display any Configurations you have or will save in the future. You can also open or close the Configurations Sidebar using the hamburger menu icon to the top left of your screen.
Sample saved configurations on the Sidebar

Creating a Configuration

You can create a new configuration using the + New Configuration button at the bottom of the Sidebar:
New Configuration button
This will give you the option to either create a Blank configuration or Load an existing one from an API Key.

Saving and Loading Configurations

Once you make your preferred changes to the new configuration you have created (such as adding subscriptions or filters), you can use the Save button to save your new configuration.
Active Save button and Reset button
An "Unsaved Changes" warning may pop to remind you that you have made changes to the configuration that you may want to save. The Save button will also become Active once there are changes that can be saved, and a Reset button will appear next to it to bring the Configuration back to its original state if you choose. Note that this will remove any unsaved changes.
Unsaved changes warning which will briefly appear
Clicking Save will display the API Key picker modal where you can pick the API key of your choosing. If you have an existing configuration saved to this key, Mempool Explorer will ask if you want to overwrite the selected key to save the new configuration. You can also create a new API key conveniently from the API Key picker modal, but please refer to your Account Page for greater flexibility in managing your API keys.
Saving to an API Key with the option to Create a new one
Once a configuration is saved to your key, it will be applied to any webhooks that you have saved to that key/blockchain/network combination and will produce the same feed that you see within Mempool Explorer.
You can load a configuration by simply clicking on it from the Sidebar. If you have Unsaved Changes in your current configuration, Mempool Explorer will remind you to save it before loading a new one. For New configurations that aren't saved, you can freely switch back and forth without losing your changes. New configurations that aren't saved will have an unsaved icon next to them:
Sample configurations with Unsaved indicator

Adding a webhook

You can conveniently add a webhook to your API key from your configurations sidebar. You will get a three-dot menu option once you hover over a configuration:
Configuration options
Note that this will add the webhook to the API key associated with that configuration, which will apply to other configurations saved to that API key on different networks. Clicking the Add Webhook option will prompt the webhook creation modal and allow you to enter your webhook details to add it:
Webhook creation modal
Once you add the webhook, a success message will appear on the corner of your screen and a Webhook icon will be added next to the configuration on your Sidebar:
A configuration with an attached webhook
You can navigate to your Account Page for greater flexibility in managing your webhooks.

Export Current Configuration

You can use your Mempool Explorer configuration to apply filters to Blocknative SDK. To do this, you can use the Export Configuration option in the three-dot menu next to your configuration to download the configuration files, and then use them to send a configuration to Blocknative SDK. You can read more on this feature on the SDK docs.
Export configuration modal

Gas Platform

Mempool Explorer provides a Gas Widget at the top right side of your screen that displays the latest Gas Price derived from Gas Platform's 80% confidence interval. You can enable the toggle next to it to view the Gas Platform payload with greater detail everytime it updates. You can learn more about Gas Platform here.
Sample Gas Widget
The Gas Widget defaults to EIP-1559 compatible type2 transaction gas prices. If you're looking for legacy type0 transaction gas prices, simply hover on the widget and you will get a checkbox option to revert it to the legacy format.
Legacy Gas Widget format with on-hover option displayed
You can also use the link that appears under the checkbox option to download our Gas Estimator browser extension.

Explore Sample Feeds

To quickly get a sense of the types of feeds you can build with Mempool Explorer, we’ve created a few samples for you:

Fullscreen mode

Mempool Explorer supports a "Fullscreen mode" that allows your feed area to take over the canvas area. This mode allows for closer monitoring of mempool events after you're done setting up your configuration. The configurations sidebar is available in Fullscreen mode for easy switching between different mempool streams you have saved. You can enter and exit Fullscreen mode using the Fullscreen button on your feed.
Fullscreen button to the right of your feed
Fullscreen Mode in effect

Share Your Mempool Explorer Feed

Blocknative allows you to easily share the feed you have created. Click on the “Share” button to copy a shortened version of the URL that includes all of the filters and display options you have selected.
You can also copy the event data in Mempool Explorer using the "Copy" button and easily share that with your team.
Share and Copy buttons to the right of your feed


For detailed information about the event payload and its properties, please check out our API docs.

Simulated Events

Blocknative notifications include simulation of pending transactions for Ethereum Main Network. These pending-simulation notifications are delivered automatically unless there is a filter that restricts notification by transaction status. Filters can use pending-simulation status to include or exclude simulation of pending transactions
Filter to Include Simulated Pending Transaction Notifications
Filter to Exclude Simulated Pending Transaction Notifications
Notifications of pending-simulation transactions appear with a slightly different background color and a badge to remind the user the transaction details are probabilistic, based on speculative execution of the transaction. See our blog post Understanding Ethereum Transaction Simulation — And Why It Matters for details on speculative execution of transactions.
Badge for Notifications of Simulated Pending Transactions
When a subscription starts to receive pending-simulation notifications, the subscription card will update with the simulation icon to make clear that notification feed includes speculative execution of some transactions.
Subscription Card with Simulated Pending Notifications Delivered
For detailed information about the event payload and its properties, please check out our API docs.
Mempool Explorer uses our API, which has rate limits. Pending Simulation has different rate limits than other notifications. Please see Rate Limits for more details.

Supported Networks

Mempool Explorer supports the following Ethereum and EVM compatible networks:
  • main
  • ropsten
  • rinkeby
  • goerli
  • kovan
  • xdai
  • bsc-main (Binance Smart Chain Main Network)
We're working to add support for the Bitcoin Network. If there are any other networks that you would need, please feel free get in touch.


If you have any questions about Mempool Explorer, join our discord.

Last modified 2mo ago