Webhook Payload

Overview

Every Streams webhook delivers a JSON payload containing the on-chain events that match your stream configuration. Payload shape depends on the chain:

EVM payloads include native transactions, internal transactions, contract logs, and free decoded ERC-20 / NFT transfers and approvals.
Bitcoin payloads include block metadata and matched transactions with output (vout) and input (vin) details.
Solana payloads include slot/block metadata and matched transactions with accountKeys, instructions, inner instructions, and pre/post token balances.

The exact contents within each chain depend on the options enabled when the stream was created.

Top-Level Payload Structure

EVM
Bitcoin
Solana

{
  "confirmed": false,
  "chainId": "0x1",
  "streamId": "uuid",
  "tag": "string",
  "retries": 0,
  "block": { },
  "logs": [],
  "txs": [],
  "txsInternal": [],
  "erc20Transfers": [],
  "erc20Approvals": [],
  "nftTransfers": [],
  "nftApprovals": { "ERC721": [], "ERC1155": [] }
}

Field	Description
`confirmed`	Whether the block is finalized
`chainId`	Hex-encoded EVM chain ID
`streamId`	Unique stream identifier
`tag`	Optional stream tag
`retries`	Number of delivery attempts
`block`	Block metadata
`logs`	Raw smart contract logs
`txs`	Native transactions
`txsInternal`	Internal (contract) transactions

{
  "confirmed": false,
  "chainId": "btc-mainnet",
  "streamId": "uuid",
  "tag": "string",
  "retries": 0,
  "block": {
    "hash": "00000000000000000003c4...",
    "height": 832150,
    "timestamp": 1709120448,
    "difficulty": "...",
    "merkleRoot": "...",
    "txCount": 3214
  },
  "txs": [
    {
      "txid": "abc...",
      "version": 2,
      "locktime": 0,
      "vin": [
        { "txid": "prev...", "vout": 0, "address": null, "value": null }
      ],
      "vout": [
        {
          "n": 0,
          "value": 3.13258866,
          "scriptPubKey": {
            "address": "bc1q...",
            "type": "witness_v0_keyhash"
          }
        }
      ]
    }
  ]
}

Field	Description
`confirmed`	`false` for the near-tip delivery (block could still be reorged), `true` once it has cleared the 2-block confirmation depth
`chainId`	`btc-mainnet`
`streamId`	Unique stream identifier
`tag`	Optional stream tag
`retries`	Number of delivery attempts
`block`	Block metadata: hash, height, timestamp, difficulty, merkle root, tx count
`txs`	Matched transactions with `txid`, `vin`, `vout`

Output values are represented as BTC decimals (e.g. 3.13258866), not satoshis. Convert with Math.round(btc * 1e8) for integer ledgers.

Mempool deliveries use the same payload shape with sentinel values: block.height: "0" and block.hash: "mempool". Branch on block.hash === "mempool" to separate pre-confirmation events from in-block events. See Mempool Notifications.

For confirmed-block deliveries, input address and value fields return null even with includeInputs: true — Bitcoin Streams reliably detects inbound transfers to watched addresses, not outflows. Mempool deliveries populate both vin and vout addresses, so sends and receives both match. See Bitcoin Streams for the full list of behaviors.

{
  "block": {
    "slot": "410060994",
    "blockHash": "7xJ9Km3V...",
    "blockHeight": "389230112",
    "blockTime": 1743436800,
    "parentSlot": "410060993",
    "previousBlockHash": "9aB2cD4e..."
  },
  "chainId": "solana_mainnet",
  "network": "mainnet",
  "retries": 0,
  "streamId": "3f6684f3-2ba4-44d7-af0e-26ee70cab245",
  "tag": "my-solana-stream",
  "confirmed": false,
  "transactions": [
    {
      "signature": "5KtP...signature_base58",
      "slot": "410060994",
      "blockTime": 1743436800,
      "fee": "5000",
      "err": null,
      "accountKeys": [
        "GoSBxCH19sMnZVEifsXeeMdEfkTv6Zh6MWvQFQF3e5m7",
        "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
        "11111111111111111111111111111111"
      ],
      "instructions": [],
      "innerInstructions": [],
      "preTokenBalances": [],
      "postTokenBalances": []
    }
  ]
}

Field	Description
`confirmed`	Whether the block is finalized
`chainId`	`solana_mainnet`
`network`	`mainnet`
`streamId`	Unique stream identifier
`tag`	Optional stream tag
`retries`	Number of delivery attempts
`block`	Slot, block hash, block height, block time, parent slot
`transactions`	Matched transactions with `signature`, `accountKeys`, instructions, etc.

Solana addresses are base58 and case-sensitive. Submit them in their original case — unlike EVM, lowercased addresses will not match.

The Solana fields you’ll reach for first: signature (transaction id), accountKeys (every account the transaction touches), instructions[].programId (which programs were invoked), preTokenBalances / postTokenBalances (SPL balance snapshots for delta calculation). For background on how Solana differs from EVM, see Solana Streams.

If you’re unfamiliar with any of these fields, see Parsed Data and Advanced Options (EVM-only).

Confirmed vs Unconfirmed Events

Streams sends two webhook payloads per match:

Unconfirmed (confirmed: false) — sent as soon as the matching transaction is included in a block (or slot, on Solana). The block is close to the chain tip and could still be reorged.
Confirmed (confirmed: true) — sent after the chain’s reorg-safety threshold has passed and the same block has been re-fetched.

This design lets you react instantly to on-chain activity, then safely update state once finality is guaranteed.

For chain-specific confirmation rules and finality models, see Supported Chains and Confirmation & Finality.For how reorgs are handled, see Re-org Handling.

Verifying Webhook Authenticity

Every webhook includes an x-signature header. You must verify this signature to ensure the payload originated from Moralis. Verification is identical for EVM, Bitcoin, and Solana payloads. Basic flow:

Read the raw request body
Hash it together with your Streams secret
Compare against x-signature

See Webhook Security for full details.

Detailed Payload Contents

EVM
Bitcoin
Solana

Native Transactions (`txs`)

Included when includeNativeTxs is enabled. Native transactions include sender and recipient, value transferred, gas usage, and receipt fields.

{
  "confirmed": false,
  "chainId": "0x1",
  "abi": [],
  "streamId": "c28d9e2e-ae9d-4fe6-9fc0-5fcde2dcdd17",
  "tag": "native_transactions",
  "retries": 0,
  "block": {
    "number": "15988759",
    "hash": "0x3aa07bd98e328db97ec273ce06b3a15fc645931fbd26337fe20c48b274277f76",
    "timestamp": "1668676247"
  },
  "logs": [],
  "txs": [
    {
      "hash": "0xd68700a0e2abd9c041eb236812e4194bf91c8182a2b03065887ab0f33d5c2958",
      "gas": "149200",
      "gasPrice": "13670412399",
      "nonce": "57995",
      "input": "0xf78dc253...",
      "transactionIndex": "52",
      "fromAddress": "0x839d4641f97153b0ff26ab837860c479e2bd0242",
      "toAddress": "0x1111111254eeb25477b68fb85ed929f73a960582",
      "value": "0",
      "type": "2",
      "v": "1",
      "r": "...",
      "s": "...",
      "receiptCumulativeGasUsed": "3131649",
      "receiptGasUsed": "113816",
      "receiptContractAddress": null,
      "receiptRoot": null,
      "receiptStatus": "1"
    }
  ],
  "txsInternal": [],
  "erc20Transfers": [],
  "erc20Approvals": [],
  "nftApprovals": { "ERC1155": [], "ERC721": [] },
  "nftTransfers": []
}

Contract Logs (`logs`)

Included when includeContractLogs is enabled. Logs contain raw topics and data, the emitting contract address, the transaction hash, and a log index. Logs are automatically decoded into higher-level objects when applicable (see below).

{
  "confirmed": false,
  "chainId": "0x1",
  "abi": [
    {
      "anonymous": false,
      "inputs": [
        { "indexed": false, "name": "reserve0", "type": "uint112" },
        { "indexed": false, "name": "reserve1", "type": "uint112" }
      ],
      "name": "Sync",
      "type": "event"
    }
  ],
  "streamId": "6378fe38-54c7-4816-8d61-fca8e128e260",
  "tag": "test_events",
  "retries": 1,
  "block": {
    "number": "15984246",
    "hash": "0x7f8d8285b572a60f6a14d5f1dcbd40e487ccffd9ec78f8dfbccb49aa191fbb95",
    "timestamp": "1668621827"
  },
  "logs": [
    {
      "logIndex": "320",
      "transactionHash": "0xf1682fa49b83689093b467ac6937785102895fc3ba418624c28d04f9af6e5e2b",
      "address": "0x4cd36d6f32586177e36179a810595a33163a20bf",
      "data": "0x00000000000000000000000000000000000000000000944ad388817e590ab607...",
      "topic0": "0x1c411e9a96e071241c2f21f7726b17ae89e3cab4c78be50e062b03a9fffbbad1",
      "topic1": null,
      "topic2": null,
      "topic3": null
    }
  ],
  "txs": [],
  "txsInternal": [],
  "erc20Transfers": [],
  "erc20Approvals": [],
  "nftApprovals": { "ERC1155": [], "ERC721": [] },
  "nftTransfers": []
}

ERC-20 Transfers

ERC-20 transfers are automatically decoded from logs and included at no additional cost. Each transfer includes from, to, value, token metadata (name, symbol, decimals), and a human-readable valueWithDecimals. Transfers appear in both confirmed and unconfirmed payloads.

{
  "confirmed": false,
  "chainId": "0x5",
  "streamId": "c4cf9b1a-0cb3-4c79-9ca3-04f11856c555",
  "tag": "ChrisWallet",
  "retries": 0,
  "block": {
    "number": "8037952",
    "hash": "0x607ff512f17f890bf9ee6206e2029cd8530819ab72b2b9161f9b90d18ece8e03",
    "timestamp": "1669667244"
  },
  "logs": [ /* ... raw Transfer log ... */ ],
  "txs": [ /* ... underlying tx ... */ ],
  "txsInternal": [],
  "erc20Transfers": [
    {
      "transactionHash": "0x1642a3b9b39e63d7fe571e7c22b80a5b059d2647fe4866d3f7105630f822d833",
      "logIndex": "132",
      "contract": "0x0041ebd11f598305d401cc1052df49219630ab79",
      "from": "0x0a46413965858a6ac4ed5184d7643dc055a4fea3",
      "to": "0xe496601436da37a045d8e88bbd6b2c2e17d8fe33",
      "value": "499999000000000000000000",
      "tokenName": "Example Token",
      "tokenSymbol": "Token",
      "tokenDecimals": "18",
      "possibleSpam": false,
      "valueWithDecimals": "499999"
    }
  ],
  "erc20Approvals": [],
  "nftApprovals": { "ERC1155": [], "ERC721": [] },
  "nftTransfers": []
}

ERC-20 Approvals

ERC-20 approvals are also automatically decoded and include owner and spender, approved amount, and token metadata.

{
  "erc20Approvals": [
    {
      "transactionHash": "0x59cd370a41c699bdb77a020b3a27735bb7442ace68ec8313040b8b9ee2672244",
      "logIndex": "135",
      "contract": "0x96beaa1316f85fd679ec49e5a63dacc293b044be",
      "owner": "0x1748789703159580520cc2ce6d1ba01e7359c44c",
      "spender": "0x1111111254eeb25477b68fb85ed929f73a960582",
      "value": "115792089237316195423570985008687907853269984665640564039457584007913129639935",
      "tokenName": "This Is Not Alpha",
      "tokenSymbol": "TINA",
      "tokenDecimals": "18",
      "valueWithDecimals": "1.15792...e+59"
    }
  ]
}

NFT Transfers

NFT transfers are automatically decoded for both ERC-721 and ERC-1155 tokens. Each NFT transfer includes:

tokenName: the name of the NFT
tokenSymbol: the symbol of the NFT (only for ERC721)
tokenContractType: the type of the NFT (either ERC721 or ERC1155)
to: the receiver address of the NFT transfer
from: the sender address of the NFT transfer
amount: the amount of NFT transferred (1 for ERC-721)
transactionHash: the transaction hash of the NFT transfer
tokenId: the token ID of the NFT transferred
operator: a third-party address approved to manage NFTs owned by from (see EIP-1155)
contract: the contract address of the NFT transferred

{
  "nftTransfers": [
    {
      "operator": null,
      "from": "0x74f64bebb1a9615fc7c2ead9c894b6ffd1803582",
      "to": "0xe496601436da37a045d8e88bbd6b2c2e17d8fe33",
      "tokenId": "0",
      "amount": "1",
      "transactionHash": "0x5ecd6b57593ab2f4f3e39fbb3318a3933e2cf9fdcf5b7ca671fb0fc2ce9dc4b5",
      "logIndex": "72",
      "contract": "0x26b4e79bca1a550ab26a8e533be97c40973b2671",
      "possibleSpam": false,
      "tokenName": "Test",
      "tokenSymbol": "SYMBOL",
      "tokenContractType": "ERC721"
    }
  ]
}

NFT Approvals

Approval events for ERC-721 and ERC-1155 tokens are grouped under nftApprovals and decoded automatically.

Smart Contract Events Only

If you configure a stream to listen only to specific contract events:

Only logs will be populated
ABI decoding is applied using the ABI you provide
No token or transaction arrays are included unless explicitly enabled

{
  "confirmed": false,
  "chainId": "0x1",
  "abi": [
    {
      "anonymous": false,
      "inputs": [
        { "indexed": false, "name": "reserve0", "type": "uint112" },
        { "indexed": false, "name": "reserve1", "type": "uint112" }
      ],
      "name": "Sync",
      "type": "event"
    }
  ],
  "streamId": "6378fe38-54c7-4816-8d61-fca8e128e260",
  "tag": "test_events",
  "retries": 1,
  "block": { /* ... */ },
  "logs": [ /* ... matching Sync logs ... */ ],
  "txs": [],
  "txsInternal": [],
  "erc20Transfers": [],
  "erc20Approvals": [],
  "nftApprovals": { "ERC1155": [], "ERC721": [] },
  "nftTransfers": []
}

Internal Transactions (`txsInternal`)

Internal transactions represent value transfers occurring inside contract execution. Included when includeInternalTxs is enabled. Useful for DeFi protocol tracing, internal fund movement, and advanced analytics.

{
  "txsInternal": [
    {
      "from": "0x1111111254eeb25477b68fb85ed929f73a960582",
      "to": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
      "value": "11000000000000000",
      "gas": "117885",
      "transactionHash": "0x0e5c3114c0ee7d29cca17aa0b8e790c4d7d25b4789bd14150f113956b5ce94de"
    }
  ]
}

Block metadata

Each Bitcoin payload begins with the block the matched transaction was included in:

hash — block hash
height — block height
timestamp — Unix timestamp
difficulty — block difficulty
merkleRoot — merkle root of transactions in the block
txCount — number of transactions in the block

Matched transactions (`txs`)

Each matched transaction includes:

txid — Bitcoin transaction id (the natural deduplication key)
version — transaction version
locktime — earliest time the transaction can be mined
vin — array of inputs (structural fields only — see warning below)
vout — array of outputs

Each vout entry has:

n — output index
value — output value as a BTC decimal (e.g. 3.13258866)
scriptPubKey.address — recipient address (P2PKH 1..., P2SH 3..., or Bech32 bc1q...)
scriptPubKey.type — script type (e.g. witness_v0_keyhash)

Even with includeInputs: true, the address and value fields on vin entries return null. You can reliably detect inbound activity to watched addresses, not outflows.

Confirmation phases

A matched transaction generates two webhook deliveries:

First delivery (near-tip) — confirmed: false, sent when the matching transaction is included in a block. The block is close to the chain tip and could still be reorged.
Second delivery (reorg-safe) — confirmed: true, sent after 2 additional blocks have been mined on top. Moralis re-fetches the block and treats the transaction as final.

Use txid as your dedupe key and upsert on the second delivery to flip your local confirmation flag.

Coinbase detection

isCoinbase is unreliable. Detect coinbase transactions with this heuristic:

const isCoinbase =
  tx.vin.length === 1 &&
  tx.vout.some((out) => out.scriptPubKey?.type === "nulldata"); // OP_RETURN

Value conversion

Convert BTC decimals to satoshis before feeding integer-based ledgers:

const btc = vout.value;
const satoshis = Math.round(btc * 1e8);

For full background, see Bitcoin Streams.

Block metadata

Each Solana payload begins with the block the matched transaction belongs to:

slot — Solana’s time unit (most slots produce a block; some are skipped)
blockHash — base58 block hash
blockHeight — block height
blockTime — Unix timestamp
parentSlot, previousBlockHash — chain links

Matched transactions (`transactions`)

Each matched transaction includes:

signature — base58-encoded transaction id (used to look up the transaction)
slot — slot the transaction was processed in
blockTime — Unix timestamp
fee — fee in lamports
err — null on success, error object otherwise
accountKeys — every account the transaction touches (signers, recipients, programs, reads, writes)
instructions — top-level instructions
innerInstructions — nested instructions emitted via Cross-Program Invocations (CPIs)
preTokenBalances / postTokenBalances — SPL balance snapshots for the affected accounts before and after the transaction

Solana addresses are base58 and case-sensitive. Submit them in their original case — unlike EVM, lowercased addresses will not match.

How filters interact with the payload

addresses matches against accountKeys — a single Solana transaction can match multiple watched addresses.
programIds matches against the program invoked by an instruction.
mintAddresses matches via pre / postTokenBalances.

Computing token deltas

Subtract preTokenBalances from postTokenBalances for the accounts you care about — no instruction replay required.

Inner instructions

Each top-level instruction can trigger inner instructions when one program calls another (CPIs). The webhook includes both, so you can trace nested behavior directly.For full background and the bridge from EVM concepts (smart contracts, ERC-20, transaction hash) to Solana concepts (programs, mint addresses, signature), see Solana Streams.

Retry Metadata

If a webhook delivery fails:

retries increments
The event is retried automatically
Failed deliveries are retained for replay (plan-dependent)

See Retries & Replays for full recovery behavior.

Common Next Steps

Depending on what you’re building:

Need cleaner decoded data? Explore Parsed Data
Need fine-grained filtering? Explore Filters
Need on-chain lookups inside webhooks (EVM only)? Explore Triggers
Handling high throughput? Explore Rate Limits

Introduction

Streams Concepts

Webhooks

Security & Reliability

EVM Streams API

Bitcoin Streams API

Solana Streams API

Utilities API

Webhook Payload

Overview

Top-Level Payload Structure

Confirmed vs Unconfirmed Events

Verifying Webhook Authenticity

Detailed Payload Contents

Native Transactions (`txs`)

Contract Logs (`logs`)

ERC-20 Transfers

ERC-20 Approvals

NFT Transfers

NFT Approvals

Smart Contract Events Only

Internal Transactions (`txsInternal`)

Block metadata

Matched transactions (`txs`)

Confirmation phases

Coinbase detection

Value conversion

Block metadata

Matched transactions (`transactions`)

How filters interact with the payload

Computing token deltas

Inner instructions

Retry Metadata

Common Next Steps

Introduction

Streams Concepts

Webhooks

Security & Reliability

EVM Streams API

Bitcoin Streams API

Solana Streams API

Utilities API

Documentation Index

​Overview

​Top-Level Payload Structure

​Confirmed vs Unconfirmed Events

​Verifying Webhook Authenticity

​Detailed Payload Contents

​Native Transactions (txs)

​Contract Logs (logs)

​ERC-20 Transfers

​ERC-20 Approvals

​NFT Transfers

​NFT Approvals

​Smart Contract Events Only

​Internal Transactions (txsInternal)

​Block metadata

​Matched transactions (txs)

​Confirmation phases

​Coinbase detection

​Value conversion

​Block metadata

​Matched transactions (transactions)

​How filters interact with the payload

​Computing token deltas

​Inner instructions

​Retry Metadata

​Common Next Steps

Overview

Top-Level Payload Structure

Confirmed vs Unconfirmed Events

Verifying Webhook Authenticity

Detailed Payload Contents

Native Transactions (`txs`)

Contract Logs (`logs`)

ERC-20 Transfers

ERC-20 Approvals

NFT Transfers

NFT Approvals

Smart Contract Events Only

Internal Transactions (`txsInternal`)

Block metadata

Matched transactions (`txs`)

Confirmation phases

Coinbase detection

Value conversion

Block metadata

Matched transactions (`transactions`)

How filters interact with the payload

Computing token deltas

Inner instructions

Retry Metadata

Common Next Steps