Overview

The Writer Actions stream contains system-level write operations recorded with an associated EVM transaction hash, including automated spot token transfers and ledger delta operations such as vault creation, staking transfers, and account activation events.

Stream Type: WRITER_ACTIONS
API Availability: gRPC Streaming API + JSON-RPC/WebSocket APIs
Volume: Low - Updates when system performs automated spot token transfers

Data Structure

Writer actions capture system operations for spot token transfers, indexed by user address, nonce, and EVM transaction hash:

{
  "local_time": "2026-04-30T19:10:43.217059852",
  "block_time": "2026-04-30T19:10:43.060250073",
  "block_number": 978911025,
  "events": [
    {
      "user": "0x200000000000000000000000000000000000012b",
      "nonce": 1184153,
      "evm_tx_hash": "0x172a41083c44c9568494fbec81d11292e192938674b861e410e4a7e965235c67",
      "action": {
        "type": "SystemSpotSendAction",
        "destination": "0x46bbfef00cde256f834340c50286dd7b495ca418",
        "token": 299,
        "wei": 56697105031
      }
    }
  ]
}

Field Definitions

Event Structure

Field	Type	Description
user	string	System user address (usually starts with 0x200000...)
nonce	integer	Unique nonce for the system operation
evm_tx_hash	string	Associated EVM transaction hash
action	object	Action details (see Action Structure below)

Action Structure

Multiple action types appear in this stream. The two system transfer types (SystemSpotSendAction and SystemSendAssetAction) share these common fields:

Field	Type	Description
type	string	Action type; see System Transfer Types and Ledger Delta Types below
destination	string	Destination address for the token transfer
token	integer	Token ID (numeric identifier for the specific token)
wei	integer	Transfer amount in wei (smallest unit)

SystemSendAssetAction Additional Fields

SystemSendAssetAction events include three additional nullable fields not present on SystemSpotSendAction:

Field	Type	Description
destinationDexOrSpot	integer|null	Target DEX/spot index for the asset transfer (0 = default spot, null when not applicable)
fromSubAccount	string|null	Source sub-account address (null when not applicable)
sourceDexOrSpot	integer|null	Source DEX/spot index for the asset transfer (0 = default spot, null when not applicable)

Ledger Delta Action Types

The following action types also appear in the writer actions stream. They record state changes written atomically with an EVM transaction hash but carry a different field layout than the system transfer types above; destination, token, and wei do not apply. See the Events dataset for the full field definitions for each delta type.

Action Type	Description	Key Fields
internalTransfer	System-initiated internal asset movement	usdc, user, destination, fee
vaultCreate	Creation of a new managed investment vault	vault, usdc
vaultLeaderCommission	Commission payment to the vault leader	user, usdc
cStakingTransfer	Cross-chain staking deposit or withdrawal (e.g., bridging HYPE for staking)	token, amount, isDeposit
accountActivationGas	Gas fee charged for activating a new account	amount, token
activateDexAbstraction	Activates DEX abstraction and seeds the user's DEX sub-account	dex, token, amount

API Usage

gRPC Streaming

// Subscribe to writer actions
const request = {
  subscribe: {
    stream_type: 'WRITER_ACTIONS',
    filters: {
      user: { values: ['0x2000000000000000000000000000000000000001'] },
      type: { values: ['SystemSpotSendAction', 'vaultCreate', 'cStakingTransfer'] }
    }
  }
};

JSON-RPC

# Get latest writer action blocks
curl -X POST https://your-endpoint.hype-mainnet.quiknode.pro/your-token/hypercore \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "hl_getLatestBlocks",
    "params": {
      "stream": "writer_actions",
      "count": 10
    },
    "id": 1
  }'

WebSocket

// Subscribe to writer actions with filters
ws.send(JSON.stringify({
  method: 'hl_subscribe',
  params: {
    streamType: 'writer_actions',
    filters: {
      user: ['0x2000000000000000000000000000000000000001'],
      type: ['SystemSpotSendAction', 'vaultCreate', 'cStakingTransfer']
    }
  }
}));

Example System Transfer Records

SystemSendAssetAction

{
  "user": "0x6af3bccd77314d35d47317e1d1bc17df248c991f",
  "nonce": 1184125,
  "evm_tx_hash": "0x299c90b15e410587841ab057f84faafa4d076a26db53c34a35231fe7dc4361bf",
  "action": {
    "type": "SystemSendAssetAction",
    "destination": "0x6043daf4fbd6bd60601d277312a0664551302e70",
    "fromSubAccount": null,
    "sourceDexOrSpot": 0,
    "destinationDexOrSpot": 0,
    "token": 0,
    "wei": 1882600
  }
}

SystemSpotSendAction - Token ID 299

{
  "user": "0x200000000000000000000000000000000000012b",
  "nonce": 1184153,
  "evm_tx_hash": "0x172a41083c44c9568494fbec81d11292e192938674b861e410e4a7e965235c67",
  "action": {
    "type": "SystemSpotSendAction",
    "destination": "0x46bbfef00cde256f834340c50286dd7b495ca418",
    "token": 299,
    "wei": 56697105031
  }
}

SystemSpotSendAction - Token ID 268

{
  "user": "0x200000000000000000000000000000000000010c",
  "nonce": 1184131,
  "evm_tx_hash": "0x350349ac511ce5c8b02964999538653a508b1ad770bc10e1921b563f0f67177c",
  "action": {
    "type": "SystemSpotSendAction",
    "destination": "0x796bc4eb6cc934d3432d5d08c74f2d957f60e7bc",
    "token": 268,
    "wei": 427229100
  }
}

SystemSpotSendAction - Token ID 0

{
  "user": "0x2000000000000000000000000000000000000000",
  "nonce": 1184132,
  "evm_tx_hash": "0xba6756dc9cbd35cfe2deb90686271df9981c6442c7f85226ce0738d5494a4649",
  "action": {
    "type": "SystemSpotSendAction",
    "destination": "0x6b9e773128f453f5c2c60935ee2de2cbc5390a24",
    "token": 0,
    "wei": 1738000000
  }
}

Important Notes

• System Operations: These are automated system-level operations, not user-initiated transfers
• Multiple Action Types: In addition to SystemSpotSendAction and SystemSendAssetAction, ledger delta types such as internalTransfer, vaultCreate, vaultLeaderCommission, cStakingTransfer, accountActivationGas, and activateDexAbstraction can appear in this stream
• Token IDs: Tokens are referenced by numeric IDs rather than symbol names (e.g., 0, 221, 269, 299) for the system transfer types
• Wei Format: All amounts are in wei format (smallest denomination) as integers for the system transfer types
• User Addresses: Often system addresses starting with 0x200000000000000000000000000000000000, but SystemSendAssetAction and ledger delta events can also have regular user addresses
• EVM Integration: Each action has an associated EVM transaction hash for cross-system tracking

Token ID Reference

Common token IDs seen in system transfers:

• Token ID 0 - Base token or ETH equivalent
• Token ID 221 - System token (specific identity varies)
• Token ID 269 - System token (specific identity varies)
• Token ID 299 - System token (specific identity varies)

Note: Many token IDs appear in practice; the full mapping is available via the Hyperliquid spotMeta Info API endpoint.

Related Streams

• Events - View balance changes and transfers that may trigger cross-environment moves
• Blocks - See the raw HyperCore transactions that initiate these transfers
• Trades - Monitor trading activity that may lead to asset movements