Action Functions, Events, and Triggers

This guide presents the three core concepts of Web3 Actions: triggers, events, and functions. You’ll learn how they work and how to use them to build your own Web3 Actions. The three core components that make up a Web3 Action are:

Functions: Custom JavaScript or TypeScript code you want to execute when an external event occurs. This is the core of your automation.
Triggers: Pre-defined external events that your Web3 Action is configured to listen for. When the event occurs, the trigger instructs Tenderly to execute your custom code (function).
Events (Trigger Types): Pre-defined external events that you can listen for by setting a trigger. When the event occurs, the trigger will call your custom code (functions).

Execution Types

Web3 Actions in Tenderly can be executed in two modes: Sequential and Parallel.

execution_type only applies to block and transaction triggers. Periodic and webhook triggers always run in parallel, and any execution_type set on them is ignored.

Web3 Action Execution Type step in the Web3 Action UI Builder

Sequential Execution

In sequential execution, actions are executed one by one in the order they were invoked. This is the default mode of execution. In this mode, each action waits for the previous action to complete before it begins execution. Here’s an example of an action configuration for a sequential execution:

example

our-org/our-cool-project:
  runtime: v2
  sources: actions
  specs:
    bestActionEver:
      description: Does the best thing ever
+     execution_type: sequential
      function: very/organized/file:bestActionEver
      trigger:
        ...

Parallel Execution

In parallel execution, actions are executed in parallel, which leads to higher throughput. In this mode, the order of execution is not guaranteed and there may be possible race conditions with action storage. Here’s an example of an action configuration for a parallel execution:

example

our-org/our-cool-project:
  runtime: v2
  sources: actions
  specs:
    bestActionEver:
      description: Does the best thing ever
+     execution_type: parallel
      function: very/organized/file:bestActionEver
      trigger:
        ...

Action functions

Web3 Action functions refer to the custom code written as standard JavaScript or TypeScript functions, but they must adhere to some rules.

Functions must be asynchronous, returning Promise<void>
Functions accept two parameters: context and event
Functions must be a named export from the file
Functions can be placed in any file under the actions root directory

Learn about the Web3 Actions project and file structure. When a Web3 Action function is deployed, the Tenderly runtime will pass the following arguments during invocation:

The context parameter that holds access to Storage and Secrets.
The event parameter that is an object with information answering the question “what just happened?”. This parameter contains data specific to the trigger type the Web3 Action function is listening for. The section Specifying triggers for external events goes into detail about external events.

The execution of Web3 Action functions is limited to 30 seconds. If your function takes longer than 30 seconds to execute, it will be terminated.

Here’s an example of a Web3 Action function written in TypeScript. The event parameter can be any one of the supported trigger types (events).

example.ts

// File: actions/myCoolTsFile.ts

// importing ethers available in Tenderly Runtime

export const awesomeActionFunction: ActionFn = async (context: Context, event: Event) => {
  // cast the event parameter to an appropriate type, based on the Trigger
  // this function subscribed to.
  // Of course, only one of these casts makes sense
  const blockEvent = event as BlockEvent;
  const periodicEvent = event as PeriodicEvent;
  const transactionEvent = event as TransactionEvent;
  const webhookEvent =  event as WebhookEvent;
	...
}

Available libraries for dashboard-based actions

The Tenderly runtime comes pre-bundled with several javascript libraries that you can import when creating Web3 Actions via the Tenderly Dashboard. Available libraries include:

To import any of these libraries, use the require() function as you would with a standard npm-based project (without ES6). Example import for Axios looks like this:

example.jsx

const axios = require('axios');

Using npm libraries for CLI-based Web3 Actions

The project created by Tenderly CLI is in fact an npm module. You can install any npm package from your actions root folder.

External events and trigger types

When an external event happens, it triggers the execution of your custom code (functions). You can choose between four external events to listen for:

Block event: A block is mined on a selected network.
Periodic event: This trigger happens when certain time intervals pass or based on CRON expressions.
Webhook event: An HTTP request is posted to the webhook URL (the Web3 Action exposes a webhook)
Transaction event: A transaction matching given filter criteria is executed on a selected network.

When defining a Web3 Action, you’ll be effectively defining triggers that react to external events of interest for your project. In the context of trigger specification, we’ll be using the term trigger type.

You should write separate functions for each trigger type. Using the same function for different trigger types is not recommended.

Subscribing Web3 Action functions to events

In addition to defining your action function in JavaScript, you also need to provide the trigger configuration, which tells Tenderly what triggers it, the external event your function subscribes to. When creating Web3 Actions via the Tenderly Dashboard, the creation flow in the UI will handle this part for you. Read the Dashboard Quickstart guide. When working with code-based Web3 Actions, functions and their triggers must be defined in the tenderly.yaml file, which is generated by Tenderly CLI. Read the CLI Quickstart guide. Example In the example below, we’re declaring a Web3 Action called bestActionEver and referencing the function awesomeActionFunction that is exported from the actions/myCoolTsFile.ts file. This is the function that Tenderly will call when the Web3 Action gets triggered. The execution is controlled via execution_type, in this case it’s set to parallel.

tenderly.yaml

account_id: ""
actions:
  our-cool-org/our-cool-project:
    runtime: v1
    sources: actions
    specs:
      bestActionEver:
        execution_type: parallel # or sequential
        description: Does the best thing ever
        function: myCoolTsFile:awesomeActionFunction
        trigger:           # trigger declaration start
          type: ...        # type
          ...              # configuration map (external event specific)

Specifying triggers for external events

In this section, we’ll examine the trigger declaration. For more information on writing tenderly.yaml file, reference this guide. The trigger type and corresponding configurations are defined in the tenderly.yaml file. You first must define the trigger object, which has two mandatory properties:

The type property, that specifies the trigger type, which can be: periodic | webhook | block | transaction
An object with a configuration specific to the selected trigger type

Below is a detailed explanation of the trigger-specific configurations for each trigger type.

Periodic event

A periodic event is used when you want your Web3 Action to be triggered at specific time intervals. It carries time: the time of invocation.

example.ts

type PeriodicEvent = {
  time: Date;
};

The trigger declaration has the periodic type. It can be interval- or cron-based:

trigger.yaml

trigger:
  type: periodic
  periodic:
    interval: 5m

The interval property can take any of the following values: 5m | 10m | 15m | 30m | 1h | 3h | 6h | 12h | 1d Use the CRON-based periodic trigger if you need more granular control over when your Web3 Action gets executed:

trigger.yaml

trigger:
  type: periodic
  periodic:
    cron: '5 */1 * * *'

The cron property can be any valid CRON string.

Webhook event

Webhook-based Web3 Actions expose a custom webhook URL, making it possible to trigger them from external systems using a simple HTTP POST request. The corresponding trigger type holds two properties: the time of invocation and any payload (a JSON object). Tenderly doesn’t perform any validation or inspections on your payload.

example.ts

type WebhookEvent = {
  time: Date;
  payload: any;
};

A trigger configuration example:

webhook-trigger.yaml

trigger:
  type: webhook
  webhook:
    authenticated: true

If authenticated is set to true, you must include the Tenderly Access Token with your request to be able to run the Web3 Action as the value of x-access-key. You can find the cURL of the exposed webhook in the Web3 Action overview in the Tenderly Dashboard.

example

curl -X POST \
-H "x-access-key: $ACCESS_TOKEN" \
-H "Content-Type: application/json" \
https://api.tenderly.co/api/v1/actions/7acc7db2-00d6-4872-b2d2-d9430bd8fe7b/webhook \
-d '{"foo": "bar"}'

Block event

The block event is used when you want to listen for the mining of blocks on one or several networks. You can make your Web3 Action “block-periodic” by specifying the number of mined blocks between two consecutive invocations.

example.ts

type BlockEvent = {
  blockHash: string;
  blockNumber: number;
  network: string;
};

When declaring the block trigger, you can specify the following properties:

network: a single value or a list of network IDs you’re interested in
blocks: the number of mined blocks between two consecutive executions of the Web3 Action. For example, execute the Web3 Action on every 100th block mined.

block-trigger.yaml

trigger:
  type: block
  block:
    network:
      - 1
      - 8453
    blocks: 100

Transaction event

The transaction trigger type allows you to listen for specific transactions as they get executed on-chain.

To listen for transactions from a smart contract, the smart contract must be verified and added to your project in the Tenderly Dashboard. The CLI will throw a warning if this is not the case.

You can specify different conditions in the form of filters to zero in on transactions of interest. Your custom code will be invoked with that exact transaction payload passed through the event parameter.

example.ts

type TransactionEvent = {
  blockHash: string;
  blockNumber: number;
  from: string;
  hash: string;
  network: string;
  to?: string;
  logs: Array<{
    address: string;
    data: string;
    topics: string[];
  }>;
  input: string;
  value: string;
  nonce: string;
  gas: string;
  gasUsed: string;
  cumulativeGasUsed: string;
  gasPrice: string;
  gasTipCap: string;
  gasFeeCap: string;
  transactionHash: string;
};

When listening for transaction events, you can also specify the following settings:

Transaction mining status: mined (the transaction has been mined) or confirmed10 (10 blocks are confirmed since the block that contains the transaction)
Filters: A list of conditions involving transaction payload using the filters list. Only transactions that match filters will trigger the execution of your code.

Filtering transactions

The filters list allows you to define triggering criteria using transaction properties to match specific transactions. Each filter in the list is an object where all fields are AND-ed together. Every condition in the filter must be true for it to match. The filters list itself is OR-ed: a transaction matches if it satisfies any single filter in the list.

match = anyOf(
  (network AND status AND from AND eventEmitted),   # Filter 1
  (network AND to)                                  # Filter 2
)

Below is a list of all available filters you can combine to build criteria for transactions that will trigger the execution of your Web3 Action.

Filter	Description
mandatory / *at least one of these must be present
network*	The network ID from which the transaction originated
status	The transaction status: fail or success
from**	The address of the transaction originator
to**	The address of the transaction recipient
eventEmitted**	An event of a specific type, emitted by a particular contract
logEmitted**	Logs emitted by a particular contract, by matching the prefix of the raw log entry
function**	Direct call to the given function. Not applicable to internal calls between the contracts
ethBalance**	An account or contract whose ETH balance meets a numeric condition at transaction time
stateChanged**	A contract whose on-chain state variable changed during the transaction, with optional value/percentage conditions
value	The value that is transferred within the transaction in wei
gasUsed	The amount of gas used by the transaction in wei
gasLimit	The gas limit set for the transaction in wei
fee	The transaction fee in wei
contract	A smart contract involved in the transaction (see contract filter)

A trigger must contain network and at least one of the following filters: from, to, function, eventEmitted, logEmitted, ethBalance, or stateChanged

An example of a transaction on Ethereum mainnet or Base sent to 0x236..fd62.

transaction-trigger.yaml

failedTransactionToMyContract:
  execution_type: parallel
  description: When sent to my contract fails
  function: observingTransactions:failedAttempts
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        # Transaction must be from Ethereum mainnet
        - network: 1
          # Transaction must have failed
          status: fail
          # Transaction must have been sent to this address
          to: 0x2364259ACD20Bd2A8dEfDc628f4099302449fd62
        # Or from Base
        - network: 8453
          # Transaction must have failed
          status: fail
          # Transaction must have been sent to this address
          to: 0x2364259ACD20Bd2A8dEfDc628f4099302449fd62

In this case, we’re interested only in transactions that are mined, matching either of these two filters:

Filter 1: network 1 (Ethereum) AND status fail AND to 0x2364...fd62
Filter 2: network 8453 (Base) AND status fail AND to 0x2364...fd62

Since we didn’t filter by any particular sender, all transactions coming to the mentioned recipient will result in the Web3 Action being triggered.

Filtering transactions by transaction fields

Among the common transaction fields, you can filter by the following properties having specific values.

from - filtering on a specific sender. Can be a single address or a list of addresses (OR-ed). Optional.
to - filtering on a specific receiver. Can be a single address or a list of addresses (OR-ed). Optional.
status - filtering on transaction status: success or fail. Can be a single value or a list (OR-ed). Optional.
network - filtering by network. Can be a single chain ID or a list of chain IDs (OR-ed). Mandatory.
contract.address - filtering only transactions involving the contract with this specific address. Optional.

All address fields must be 0x-prefixed, 40 hex characters (e.g. 0xf63c48626f874bf5604D3Ba9f4A85d5cE58f8019).

list-fields.yaml

filters:
  - network:                  # list of networks (OR-ed)
      - 1
      - 8453
    status:                   # list of statuses (OR-ed)
      - success
      - fail
    from:                     # list of sender addresses (OR-ed)
      - 0x7ebB3Dca1C281b23D5B73175f10cA5A0a309B01F
      - 0xD3a02149A236b2547Cc3C897Fb41C1a962f881AE
    to:                       # list of recipient addresses (OR-ed)
      - 0x003b3625cDcb5958E9709F4Ba8E340Cb0783DeaE
      - 0x26997bd8473E0Dd0b37eB1711B7c1eE2354d78e4

You can also query numerics related to exchanged value and gas, using relational operators. All of the following are in wei:

value
gasUsed
gasLimit
fee

Numeric fields accept either a single comparison object or a list of comparison objects. When a list is provided, comparisons are OR-ed. Within a single comparison object, all operators are AND-ed. You can use any of the common comparison operators: eq, gte, gt, lt, lte. You can also use the not boolean flag to negate a comparison.

Operator	Meaning
`eq`	Equal to
`gt`	Greater than
`gte`	Greater than or equal to
`lt`	Less than
`lte`	Less than or equal to
`not`	Boolean. Set to `true` to negate the comparison (e.g. match when value is not in range)

Below is an example of a filter demonstrating filters using scalar values in the transaction payload.

numeric-filters.yaml

filters:
  - network: 1
    to: 0x003b3625cDcb5958E9709F4Ba8E340Cb0783DeaE
    # Single comparison object (operators AND-ed within)
    value:
      gte: 100
      lte: 1000
    # List of comparison objects (OR-ed between entries)
    gasLimit:
      - lt: 100
      - gt: 1000
    gasUsed:
      eq: 9999
    fee:
      - lte: 100
      - gte: 1000

Using the not flag to negate a comparison:

negated-comparison.yaml

filters:
  - network: 1
    to: 0x003b3625cDcb5958E9709F4Ba8E340Cb0783DeaE
    # Matches when value is NOT between 100 and 1000
    value:
      gte: 100
      lte: 1000
      not: true

Filtering transactions using emitted EVM Events

Configuring Web3 Actions to listen for EVM events emitted by a transaction execution allows you to respond to significant changes logged by these events. You can achieve this by using the eventEmitted operator, which supports the following nested properties:

contract (mandatory): To specify the origin of the event.
- contract.address: The address of the contract that emitted the event.
- contract.invocation: Controls how the contract was called: direct, internal, or any (default). See contract filter for details.
name: The name of the event (requires a verified contract).
id: The topic hash of the event signature (alternative to name). Useful for unverified contracts where the ABI is not available. For example, the Transfer(address,address,uint256) event has the topic hash 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef.
not: Boolean. Set to true to negate the entire event match, including parameters (trigger when the event is not emitted with the specified parameters).
parameters: A list of conditions on decoded event argument values. All conditions are AND-ed: every condition must match. Each entry supports:
- name (required): The name of the event argument.
- string: String comparison. Accepts a plain string for exact match, or an object with exact and not fields. See StringComparison for details.
- int: Integer comparison. Supports the same operators as numeric filters (eq, gt, gte, lt, lte). All operators within a single int block are AND-ed. Use the not flag to negate the combined condition. See IntComparison for details.

There is no OR within a single eventEmitted entry’s parameters. All conditions are AND-ed. For OR logic on the same parameter, use multiple eventEmitted entries (which are OR-ed in the outer list).

To use the eventEmitted filter with name or parameters, the contract must be verified and added to the project in the Tenderly Dashboard. Use id (topic hash) for unverified contracts.

For the complete field reference, see EventFilter. Below is an example of a Web3 Action that will be invoked when either TxSubmission or TxConfirmation event is emitted when the smart contract is executed at the address 0x418d..9d45 on Sepolia.

event-emitted-filter.yaml

txSubmittedOrConfirmed:
  description: When any of TxSubmission and TxConfirmation is emitted
  execution_type: parallel
  function: myCoolJsFile:myCoolFunction
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        - network: 11155111
          eventEmitted:
            contract:
              address: 0x418ebb95eaa40c119408143056cad984c6129d45
            name: TxSubmission
        - network: 11155111
          eventEmitted:
            contract:
              address: 0x418ebb95eaa40c119408143056cad984c6129d45
            name: TxConfirmation

Here is an example filtering by decoded event parameters. All parameter conditions are AND-ed:

event-parameters.yaml

filters:
  - network: 8453
    eventEmitted:
      contract:
        address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
      name: Transfer
      parameters:
        - name: from
          string: "0x8F362C3dd5301Ce1b43ea3A278E3f12c1807C271"
        - name: value
          int:
            gte: 1000000           # >= 1 USDC (6 decimals)

Numeric range with negation on parameters:

negated-parameter.yaml

filters:
  - network: 1
    eventEmitted:
      contract:
        address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
      name: Transfer
      parameters:
        - name: value
          int:
            gte: 100
            lte: 1000
            not: true              # matches when value < 100 OR value > 1000

For OR logic on parameters, use multiple eventEmitted entries:

event-parameter-or.yaml

filters:
  - network: 1
    eventEmitted:
      # Entry 1: value < 100
      - contract:
          address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
        name: Transfer
        parameters:
          - name: value
            int:
              lt: 100
      # Entry 2: value > 1000 (OR-ed with entry 1)
      - contract:
          address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
        name: Transfer
        parameters:
          - name: value
            int:
              gt: 1000

Using not on the event itself to negate the entire match:

negated-event.yaml

filters:
  - network: 1
    eventEmitted:
      contract:
        address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
      name: Transfer
      parameters:
        - name: from
          string: "0x0000000000000000000000000000000000000000"
      not: true   # matches when no Transfer event from the zero address is found

Filtering transactions by emitted logs

Another way to listen for EVM events is to query them by the log topic. The logEmitted filter can be a single object or a list (entries are OR-ed). It supports the following properties:

startsWith (mandatory): A list of topic values to match against the transaction’s log topics. Each entry is compared by exact equality (case-insensitive) to the corresponding topic. In practice these are full 32-byte topic hashes (0x-prefixed, 64 hex chars), but the field accepts any valid hex string.
contract.address (optional): The source of the logs. When specified, only logs from this contract are matched.
matchAny: Boolean. When true, matching any single topic from startsWith is sufficient. When false (default), all topics must match.
not: Boolean. Set to true to negate the entire log match (trigger when the log is not emitted).

Using logEmitted enables you to use the event topic prefix in its raw form to filter for events. This is useful if you’re setting up a Web3 Action on an unverified contract.

For the complete field reference, see LogFilter. Below is an example of a Web3 Action that will be invoked when a transaction contains log entries starting with the given prefixes.

log-emitted-filter.yaml

txEmittedSomeLogs:
  description: When particular logs are emitted
  function: observingTransactions:someLogsEmittedAction
  execution_type: parallel
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        - network: 11155111
          logEmitted:
            # Transaction must have emitted a log entry
            contract:
              address: 0x418ebb95eaa40c119408143056cad984c6129d45
            startsWith:
              # and topics of the log entry must start with either one of these
              - 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef
              - 0x0000000000000000000000000000000000000000000000000000000000000000

Filtering transactions involving a specific contract

To filter for transactions that call a specific contract during their execution, you can use the optional contract filter. The contract filter supports the following properties:

address: The address of the contract.
invocation: Controls how the contract was called. Possible values:
- direct: the contract was called directly by the transaction sender (EOA). Use this when you only care about top-level calls to the contract.
- internal: the contract was called internally by another contract during execution (e.g. via CALL, DELEGATECALL, or STATICCALL opcodes). Use this to detect when your contract is invoked as part of a multi-contract interaction.
- any: matches both direct and internal calls. This is the default.

The invocation field is available wherever a contract object is used, including inside eventEmitted filters. For example, you can use invocation: internal on an eventEmitted contract to only match events emitted during internal calls. See Contract for the schema.

invocation is not supported on logEmitted. Only contract.address is used to restrict log matching; the invocation type is ignored.

In the example below, the first filter matches any successful transaction sent to 0x2364...fd62 on Sepolia. The second filter is more restrictive: only transactions that also involve an internal call to contract 0xad88...80d6 will trigger the Web3 Action.

contract-filter.yaml

contractInvocationAction:
  description: When my contract is called directly or internally
  execution_type: parallel
  function: observingTransactions:contractCalls
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        # Any successful transaction sent to this address
        - network: 11155111
          status: success
          to: 0x2364259ACD20Bd2A8dEfDc628f4099302449fd62
        # Only transactions that internally call this contract
        - network: 11155111
          status: success
          to: 0x2364259ACD20Bd2A8dEfDc628f4099302449fd62
          contract:
            address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6
            invocation: internal

Filtering transactions by function call

To filter for transactions that directly call a specific function, you can use the optional function filter. It requires the address of the contract contract.address and either the name or signature of the function. The function filter supports the following properties:

contract (mandatory): To specify the target contract.
- contract.address: The address of the contract being called.
- contract.invocation: Controls how the function must be called: any (default, both direct and internal), direct (EOA-initiated only), or internal (sub-calls only). See contract filter for details.
name: The name of the function (requires a verified contract).
signature: The 4-byte function selector (e.g. 0xa9059cbb). Useful for unverified contracts where the ABI is not available.
not: Boolean. Set to true to negate the entire function match, including parameters (trigger when the function is not called with the specified parameters).
parameters: A list of conditions on decoded function input argument values. All conditions are AND-ed: every condition must match. Each entry supports:
- name (required): The name of the function argument.
- string: String comparison. Accepts a plain string for exact match, or an object with exact and not fields. See StringComparison for details.
- int: Integer comparison. Supports the same operators as numeric filters (eq, gt, gte, lt, lte). All operators within a single int block are AND-ed. Use the not flag to negate the combined condition. See IntComparison for details.

There is no OR within a single function entry’s parameters. All conditions are AND-ed. For OR logic on the same parameter, use multiple function entries (which are OR-ed in the outer list).

To use the function filter with name or parameters, the contract must be verified and added to the project in the Tenderly Dashboard. Use signature (4-byte selector) for unverified contracts.

You can specify function as a single object or as a list. When a list is provided, entries are OR-ed. The filter matches if any function in the list is called. For the complete field reference, see FunctionFilter. Below is an example of a Web3 Action trigger responding to any call (direct or internal) to the verySpecialFunction of the contract deployed at 0xad88...80d6.

function-filter.yaml

failedTransactionToMyContract:
  description: When sent to my contract fails
  execution_type: parallel
  function: observingTransactions:failedAttempts
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        # Transaction must be from Ethereum mainnet
        - network: 1
          # Transaction must have failed
          status: fail
          function:
            # the function verySpecialFunction must have been called (direct or internal)
            name: verySpecialFunction
            contract:
              address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6

You can also match by function selector and use multiple function entries:

function-selector.yaml

filters:
  - network: 1
    function:
      # Match by 4-byte selector (useful for unverified contracts)
      - signature: "0xa9059cbb"
        contract:
          address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6
      # Match by name (requires verified contract)
      - name: approve
        not: true  # negate: trigger when approve is NOT called
        contract:
          address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6

Here is an example filtering by decoded function input parameters. All parameter conditions are AND-ed:

function-parameters.yaml

filters:
  - network: 1
    function:
      name: transfer
      contract:
        address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
      parameters:
        - name: to
          string: "0x8F362C3dd5301Ce1b43ea3A278E3f12c1807C271"
        - name: amount
          int:
            gte: 1000000           # >= 1 USDC (6 decimals)

String negation, trigger when the recipient is not a specific address:

function-negated-string.yaml

filters:
  - network: 1
    function:
      name: transfer
      contract:
        address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
      parameters:
        - name: to
          string:
            exact: "0xa59a97Ab934aE02A1E0561ea0f4F6C275Fc148B4"
            not: true              # matches when 'to' is NOT this address

Numeric range with negation on parameters:

function-negated-parameter.yaml

filters:
  - network: 1
    function:
      name: transfer
      contract:
        address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
      parameters:
        - name: amount
          int:
            gte: 100
            lte: 1000
            not: true              # matches when amount < 100 OR amount > 1000

For OR logic on parameters, use multiple function entries:

function-parameter-or.yaml

filters:
  - network: 1
    function:
      # Entry 1: amount < 100
      - name: transfer
        contract:
          address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
        parameters:
          - name: amount
            int:
              lt: 100
      # Entry 2: amount > 1000 (OR-ed with entry 1)
      - name: transfer
        contract:
          address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
        parameters:
          - name: amount
            int:
              gt: 1000

To match only internal calls, for example, a transfer triggered by a router or flash-loan provider rather than directly by a user, set invocation: internal. This example triggers only when another contract internally calls transfer on USDC for at least 1,000 USDC:

function-internal-with-params.yaml

filters:
  - network: 1
    function:
      name: transfer
      contract:
        address: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
        invocation: internal       # sub-calls only — excludes direct EOA calls
      parameters:
        - name: amount
          int:
            gte: 1000000000        # >= 1,000 USDC (6 decimals)

Filtering transactions by ETH balance

The ethBalance filter triggers your Web3 Action when an account or contract’s ETH balance meets a numeric condition during a transaction. This is useful for monitoring large whale movements, protocol treasury thresholds, or wallet funding events. The filter supports the following properties:

address (mandatory): The account or contract address to monitor.
balanceCmp (mandatory): A numeric comparison against the balance at transaction time. Uses BigIntComparison operators (eq, gt, gte, lt, lte). Values are in wei and can be provided as decimal strings (e.g. "1000000000000000000") or 0x-prefixed hex (e.g. "0xde0b6b3a7640000").
not (optional): Set to true to negate the entire match.

You can provide a single ethBalance object or a list, entries are OR-ed. For the complete field reference, see EthBalanceFilter. Example: trigger when a wallet’s balance reaches at least 1 ETH:

eth-balance-filter.yaml

balanceWatcher:
  description: Alert when wallet reaches 1 ETH
  function: watchers:onBalanceReached
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        - network: 1
          ethBalance:
            address: "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"   # vitalik.eth
            balanceCmp:
              gte: "1000000000000000000"   # 1 ETH in wei

Example: multiple accounts monitored in one filter (OR-ed):

eth-balance-multi.yaml

filters:
  - network: 1
    ethBalance:
      - address: "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"   # vitalik.eth
        balanceCmp:
          gte: "1000000000000000000"
      - address: "0xBE0eB53F46cd790Cd13851d5EFf43D12404d33E8"   # Binance cold wallet
        balanceCmp:
          lte: "500000000000000000"   # below 0.5 ETH

Example: balance within a range:

eth-balance-range.yaml

filters:
  - network: 1
    ethBalance:
      address: "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"   # vitalik.eth
      balanceCmp:
        gte: "1000000000000000000"   # >= 1 ETH
        lte: "2000000000000000000"   # <= 2 ETH

Example: trigger when a wallet’s balance is not below 1 ETH (i.e. negating the condition):

eth-balance-not.yaml

filters:
  - network: 1
    ethBalance:
      address: "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"   # vitalik.eth
      balanceCmp:
        lt: "1000000000000000000"   # < 1 ETH
      not: true                     # negate: trigger when balance is NOT below 1 ETH

Filtering transactions by contract state changes

The stateChanged filter triggers your Web3 Action when a contract’s state variable changes during a transaction. You can match on any combination of: whether the variable changed at all, a specific new value, a percentage change, or a raw storage slot key. The filter supports the following properties:

address (mandatory unless matchAny: true): The contract address to watch.
matchAny (optional): When true, matches state changes on any contract in the transaction, address can be omitted. Useful for protocol-wide monitoring.
params (optional): A list of state variable conditions. All entries are AND-ed. When omitted, the filter matches any state change on the specified address.
not (optional): Set to true to negate the entire match.

Each entry in params requires:

name (mandatory): The name of the state variable.
At least one condition:
- change: true: matches when the variable’s value changed at all.
- valueCmp (BigIntComparison), matches when the new value meets a numeric condition.
- percentageCmp (BigIntComparison), matches on the signed percentage change computed as (newValue - oldValue) * 100 / oldValue. Positive values mean an increase, negative values mean a decrease. For example, gte: "10" fires on increases of 10%+; lte: "-10" fires on decreases of 10%+. Note: when oldValue is 0, the percentage is always 0, use change: true or valueCmp instead.
- storageSlotKey: matches by raw storage slot key (useful for unverified contracts).

For the complete field reference, see StateChangedFilter.

To use name-based state variable matching, the contract must be verified and added to your project in the Tenderly Dashboard.

Example: trigger when totalSupply changes at all:

state-changed-basic.yaml

stateWatcher:
  description: Alert on any totalSupply change
  function: watchers:onStateChange
  trigger:
    type: transaction
    transaction:
      status:
        - mined
      filters:
        - network: 1
          stateChanged:
            address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
            params:
              - name: totalSupply
                change: true

Example: trigger when totalSupply reaches a threshold:

state-changed-value.yaml

filters:
  - network: 1
    stateChanged:
      address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
      params:
        - name: totalSupply
          valueCmp:
            gte: "1000000000000000000000"   # >= 1000 DAI (18 decimals)

Example: trigger when totalSupply increases by 50% or more:

state-changed-percentage-increase.yaml

filters:
  - network: 1
    stateChanged:
      address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
      params:
        - name: totalSupply
          percentageCmp:
            gte: "50"   # positive = increase; fires when totalSupply grew by >= 50%

Example: trigger when totalSupply decreases by 10% or more:

state-changed-percentage-decrease.yaml

filters:
  - network: 1
    stateChanged:
      address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
      params:
        - name: totalSupply
          percentageCmp:
            lte: "-10"   # negative = decrease; fires when totalSupply dropped by >= 10%

Example: multiple param conditions AND-ed (totalSupply changed AND new value is above a floor):

state-changed-multi-params.yaml

filters:
  - network: 1
    stateChanged:
      address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
      params:
        - name: totalSupply
          change: true
        - name: totalSupply
          valueCmp:
            gte: "1000000000000000000000000"   # new totalSupply still >= 1 million DAI

Example: watch a specific mapping slot (e.g. balances[bob]) using a raw storage slot key: For mappings, there is no named variable per entry, use storageSlotKey with the keccak256-derived slot for the key you care about. The slot for mapping(address => uint256) balances at storage slot N and key addr is keccak256(abi.encode(addr, N)).

state-changed-slot.yaml

filters:
  - network: 1
    stateChanged:
      address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"   # DAI on mainnet
      params:
        # slot = keccak256(abi.encode(bob_address, mapping_slot_index))
        # compute this off-chain with ethers.js: ethers.solidityPackedKeccak256(["address", "uint256"], [bobAddress, slotIndex])
        - storageSlotKey: "0x<precomputed-slot-hash>"
          change: true

The storageSlotKey approach works for unverified contracts and any storage layout, it does not require the contract to be verified or added to your Tenderly project. Example: matchAny to monitor any contract in the transaction:

state-changed-match-any.yaml

filters:
  - network: 1
    function:
      name: liquidate
      contract:
        address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6
    stateChanged:
      matchAny: true
      params:
        - name: collateralBalance
          change: true

stateChanged and ethBalance can be combined with any other filter in the same filter object, all fields are AND-ed. The examples below show common real-world combinations. Example: mint() was called AND totalSupply changed (confirm the call had on-chain effect):

state-changed-with-function.yaml

filters:
  - network: 8453
    function:
      name: mint
      contract:
        address: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
    stateChanged:
      address: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
      params:
        - name: totalSupply
          change: true

Example: Transfer event emitted AND paused state changed (ownership or pause flag toggled during a transfer):

state-changed-with-event.yaml

filters:
  - network: 8453
    eventEmitted:
      contract:
        address: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
      name: Transfer
    stateChanged:
      address: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
      params:
        - name: paused
          change: true

Example: any call to a contract AND the caller’s ETH balance is above a threshold:

eth-balance-with-to.yaml

filters:
  - network: 8453
    to: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
    ethBalance:
      address: "0x4786f86f7d9d1467928b3518f123ea4fb65f1500"
      balanceCmp:
        gte: "500000000000000"   # caller has >= 0.0005 ETH

Example: trigger when togglePause() was called but balances did not change (i.e. the tx affected only the paused flag):

state-changed-not.yaml

filters:
  - network: 8453
    to: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
    stateChanged:
      address: "0x0232b6c44752020C645b65CAA68c139ab456Ec37"
      params:
        - name: balances
          change: true
      not: true   # negate: trigger when balances did NOT change

Complete transaction trigger reference

The following annotated YAML block shows every available field for transaction triggers in one place. Use it as a quick reference when building your trigger configuration. For type definitions, see the Trigger YAML schema reference below.

complete-reference.yaml

trigger:
  type: transaction
  transaction:
    status:
      - mined              # or confirmed10

    # At least one filter must match (OR logic).
    # Within a filter, all fields are AND-ed.
    filters:
      - network: 1                                          # mandatory (single or list)
        status: success                                     # fail | success (single or list)
        from: "0xDB6Fd484cFA46eeB73c71165C6C004B50309BbE1" # single or list of addresses
        to: "0x2364259ACD20Bd2A8dEfDc628f4099302449fd62"   # single or list of addresses

        # --- Contract filter ---
        contract:
          address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6
          invocation: any    # any | direct | internal

        # --- Numeric comparisons (all in wei) ---
        # Each can be a single object or a list (OR-ed between entries).
        # Within a single object, all operators are AND-ed.
        value:
          gte: 1000000000000000000   # >= 1 ETH
          not: false                 # set true to negate
        gasUsed:
          eq: 21000
        gasLimit:                    # list form (OR-ed)
          - lt: 100
          - gt: 1000
        fee:
          - lte: 100
          - gte: 1000

        # --- Event filter (single object or list, OR-ed) ---
        eventEmitted:
          - contract:
              address: 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913
            name: Transfer           # match by event name (verified contract)
            # id: "0xddf252..."      # alternative: match by topic hash
            not: false               # negate entire event match
            parameters:              # filter by decoded event arguments (AND-ed)
              - name: from
                string: "0x8F362C3dd5301Ce1b43ea3A278E3f12c1807C271"
              - name: value
                int:
                  gte: 1000000       # >= 1 USDC (6 decimals)

        # --- Log filter (single object or list, OR-ed) ---
        logEmitted:
          - startsWith:
              - "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"
            contract:
              address: 0x418ebb95eaa40c119408143056cad984c6129d45
            matchAny: false          # true = match any single topic
            not: false               # negate entire log match

        # --- Function filter (single object or list, OR-ed) ---
        function:
          - name: transfer           # match by name (verified contract)
            contract:
              address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6
              invocation: any        # any (default) | direct | internal
            not: false               # negate entire function + parameters match
            parameters:              # filter by decoded function arguments (AND-ed)
              - name: to
                string: "0x8F362C3dd5301Ce1b43ea3A278E3f12c1807C271"  # short form
              - name: from
                string:              # long form (with negation)
                  exact: "0xa59a97Ab934aE02A1E0561ea0f4F6C275Fc148B4"
                  not: true          # negate this string match
              - name: amount
                int:
                  gte: 1000000       # >= 1 USDC (6 decimals)
          # name and signature are mutually exclusive — each entry uses one or the other, not both
          - signature: "0xa9059cbb"  # match by 4-byte selector (0x + 8 hex chars)
            not: true                # negate this function match
            contract:
              address: 0xad881d3d06c7f168715b84b54f9d3e1ff27b80d6

        # --- ETH balance filter (single object or list, OR-ed) ---
        ethBalance:
          address: "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"  # vitalik.eth
          balanceCmp:
            gte: "1000000000000000000"  # >= 1 ETH in wei (decimal or 0x-prefixed hex)
          not: false                    # negate the balance match

        # --- State changed filter (single object or list, OR-ed) ---
        stateChanged:
          address: "0x6B175474E89094C44Da98b954EedeAC495271d0F"  # DAI on mainnet
          matchAny: false               # true = match any contract in the transaction
          not: false                    # negate the entire state change match
          params:                       # all entries AND-ed
            - name: totalSupply         # state variable name (verified contract)
              change: true              # matches when the value changed at all
            - name: totalSupply
              valueCmp:                 # BigIntComparison on the new value
                gte: "1000"
            - name: totalSupply
              percentageCmp:            # signed: (newVal-oldVal)*100/oldVal
                gte: "50"               # >= 50 means increased by >= 50%
                                        # use lte: "-50" to match a decrease of >= 50%

Trigger YAML schema reference

The schema below describes the structure and types of every field accepted by the trigger configuration. Use it alongside the annotated example above when building your tenderly.yaml. Notation: ? = optional, | = one of, [] = list. Fields marked “single or list” accept either a scalar value or a YAML list.

All trigger types

schema.yaml

trigger:
  type: periodic | webhook | block | transaction

  periodic:               # when type = periodic
    interval: string?     # "5m" | "10m" | "15m" | "30m" | "1h" | "3h" | "6h" | "12h" | "1d"
    cron: string?         # standard cron expression (mutually exclusive with interval)

  webhook:                # when type = webhook
    authenticated: bool?  # default: true

  block:                  # when type = block
    network: Network      # single chain ID or list of chain IDs
    blocks: int           # run every N blocks (must be > 0)

  transaction:            # when type = transaction
    status: TransactionStatus[]    # "mined" | "confirmed10"
    filters: TransactionFilter[]   # at least one filter required

TransactionFilter

schema.yaml

# All fields within a filter are AND-ed.
# Multiple filters in the list are OR-ed.

TransactionFilter:
  network: Network                # required. single chain ID or list (OR-ed)
  status: Status                  # optional. single or list: "success" | "fail" (OR-ed)
  from: Address                   # optional. single or list of addresses (OR-ed)
  to: Address                     # optional. single or list of addresses (OR-ed)
  value: IntComparison            # optional. single object or list (OR-ed)
  gasUsed: IntComparison          # optional. single object or list (OR-ed)
  gasLimit: IntComparison         # optional. single object or list (OR-ed)
  fee: IntComparison              # optional. single object or list (OR-ed)
  contract: Contract              # optional. shared default — applied to function/eventEmitted that omit their own contract
  function: FunctionFilter        # optional. single object or list (OR-ed)
  eventEmitted: EventFilter       # optional. single object or list (OR-ed)
  logEmitted: LogFilter           # optional. single object or list (OR-ed)
  ethBalance: EthBalanceFilter    # optional. single object or list (OR-ed)
  stateChanged: StateChangedFilter  # optional. single object or list (OR-ed)
  # constraint: at least one of from, to, function, eventEmitted, logEmitted, ethBalance, or stateChanged is required

At least one of from, to, function, eventEmitted, logEmitted, ethBalance, or stateChanged must be present in each filter.

The top-level contract field acts as a shared default for the filter. It is automatically applied to any function or eventEmitted entry that does not specify its own contract, letting you avoid repeating the same address. It does not apply to logEmitted.

Shared types

schema.yaml

Address: string                   # 0x-prefixed, 40 hex characters (case-insensitive)

Network: int | int[]              # chain ID(s)

Status: string | string[]        # "success" | "fail"

Contract:
  address: Address                # required
  invocation: string?             # "any" (default) | "direct" | "internal"

IntComparison:                    # single object or list of objects (OR-ed)
  eq: int?                        # equal to
  gt: int?                        # greater than
  gte: int?                       # greater than or equal
  lt: int?                        # less than
  lte: int?                       # less than or equal
  not: bool?                      # negate the combined condition

BigIntComparison:                 # used by ethBalance and stateChanged filters
  # values are decimal strings ("1000000000000000000") or 0x-prefixed hex ("0xde0b6b3a7640000")
  # for percentageCmp: signed value, (newVal-oldVal)*100/oldVal — positive=increase, negative=decrease
  eq: string?                     # equal to
  gt: string?                     # greater than
  gte: string?                    # greater than or equal
  lt: string?                     # less than
  lte: string?                    # less than or equal
  not: bool?                      # negate the combined condition
  # at least one of eq, gt, gte, lt, lte must be set

StringComparison:                 # accepts a plain string OR an object
  # Short form:  string: "0xdead..."        → exact match, not = false
  # Long form:   string: { exact: "0xdead...", not: true }
  exact: string?                  # exact match (case-insensitive)
  not: bool?                      # negate the match

FunctionFilter

schema.yaml

FunctionFilter:                   # single object or list (OR-ed)
  contract: Contract              # required
  name: string?                   # function name (requires verified contract)
  signature: string?              # 4-byte selector, 0x-prefixed, 8 hex chars
  not: bool?                      # negate entire function + parameters match
  parameters: ParameterCondition[]?
  # note: name and signature are mutually exclusive (use one or the other)
  # note: parameters requires a verified contract (name must be set, not signature)

ParameterCondition:               # all conditions in the list are AND-ed
  name: string                    # required. function argument name
  string: StringComparison?       # string comparison (plain string or { exact, not })
  int: IntComparison?             # numeric comparison

EventFilter (eventEmitted)

schema.yaml

EventFilter:                      # single object or list (OR-ed)
  contract: Contract              # required
  name: string?                   # event name (requires verified contract)
  id: string?                     # topic hash, 0x-prefixed, 64 hex chars
  not: bool?                      # negate entire event + parameters match
  parameters: ParameterCondition[]?
  # note: name and id are mutually exclusive (use one or the other)
  # note: see ParameterCondition definition under FunctionFilter above

LogFilter (logEmitted)

schema.yaml

LogFilter:                        # single object or list (OR-ed)
  startsWith: string[]            # required. hex strings (typically 0x + 64 hex chars for full topic hashes)
  contract: Contract?             # optional. restrict to logs from this contract address
  # note: invocation is not supported for logEmitted; only contract.address is used
  matchAny: bool?                 # true = match any topic; false (default) = match all
  not: bool?                      # negate entire log match

EthBalanceFilter (ethBalance)

schema.yaml

EthBalanceFilter:                 # single object or list (OR-ed)
  address: Address                # required. account or contract address to monitor
  balanceCmp: BigIntComparison    # required. condition on the ETH balance in wei
  not: bool?                      # negate the balance match

StateChangedFilter (stateChanged)

schema.yaml

StateChangedFilter:               # single object or list (OR-ed)
  address: Address?               # required unless matchAny = true
  matchAny: bool?                 # true = match state changes on any contract in the transaction
  params: StateChangedParamCondition[]?  # optional. when omitted, matches any state change on address
  not: bool?                      # negate the entire state change match

StateChangedParamCondition:       # all entries in the params list are AND-ed
  name: string                    # required. state variable name (verified contract)
  # at least one of the following must be set:
  change: bool?                   # true = matches when the variable changed at all
  valueCmp: BigIntComparison?     # condition on the new value
  percentageCmp: BigIntComparison?  # signed: (newVal-oldVal)*100/oldVal
                                  #   gte: "10"  → increased by >= 10%
                                  #   lte: "-10" → decreased by >= 10%
                                  #   returns 0 when oldVal is 0; use valueCmp or change: true instead
  storageSlotKey: string?         # raw storage slot key (useful for unverified contracts)

Getting Started

Simulator

Console

Monitor

Node RPC

Account & Settings

Action Functions, Events, and Triggers

Execution Types

Sequential Execution

Parallel Execution

Action functions

Available libraries for dashboard-based actions

Using npm libraries for CLI-based Web3 Actions

External events and trigger types

Subscribing Web3 Action functions to events

Specifying triggers for external events

Periodic event

Webhook event

Block event

Transaction event

Filtering transactions

Filtering transactions by transaction fields

Filtering transactions using emitted EVM Events

Filtering transactions by emitted logs

Filtering transactions involving a specific contract

Filtering transactions by function call

Filtering transactions by ETH balance

Filtering transactions by contract state changes

Complete transaction trigger reference

Trigger YAML schema reference

All trigger types

TransactionFilter

Shared types

FunctionFilter

EventFilter (eventEmitted)

LogFilter (logEmitted)

EthBalanceFilter (ethBalance)

StateChangedFilter (stateChanged)

​Execution Types

​Sequential Execution

​Parallel Execution

​Action functions

​Available libraries for dashboard-based actions

​Using npm libraries for CLI-based Web3 Actions

​External events and trigger types

​Subscribing Web3 Action functions to events

​Specifying triggers for external events

​Periodic event

​Webhook event

​Block event

​Transaction event

​Filtering transactions

​Filtering transactions by transaction fields

​Filtering transactions using emitted EVM Events

​Filtering transactions by emitted logs

​Filtering transactions involving a specific contract

​Filtering transactions by function call

​Filtering transactions by ETH balance

​Filtering transactions by contract state changes

​Complete transaction trigger reference

​Trigger YAML schema reference

​All trigger types

​TransactionFilter

​Shared types

​FunctionFilter

​EventFilter (eventEmitted)

​LogFilter (logEmitted)

​EthBalanceFilter (ethBalance)

​StateChangedFilter (stateChanged)

Execution Types

Sequential Execution

Parallel Execution

Action functions

Available libraries for dashboard-based actions

Using npm libraries for CLI-based Web3 Actions

External events and trigger types

Subscribing Web3 Action functions to events

Specifying triggers for external events

Periodic event

Webhook event

Block event

Transaction event

Filtering transactions

Filtering transactions by transaction fields

Filtering transactions using emitted EVM Events

Filtering transactions by emitted logs

Filtering transactions involving a specific contract

Filtering transactions by function call

Filtering transactions by ETH balance

Filtering transactions by contract state changes

Complete transaction trigger reference

Trigger YAML schema reference

All trigger types

TransactionFilter

Shared types

FunctionFilter

EventFilter (eventEmitted)

LogFilter (logEmitted)

EthBalanceFilter (ethBalance)

StateChangedFilter (stateChanged)