EVM Portal API Reference - SQD Documentation

This page provides a quick reference for the Portal API. For the complete OpenAPI specification with all fields and options:

Complete EVM API Specification

View the full OpenAPI documentation with all available fields, filters, and detailed schemas →

Base URL

All Portal requests are made to:

https://portal.sqd.dev/datasets/{network}

Replace {network} with your target blockchain (e.g., ethereum-mainnet, polygon-mainnet, arbitrum-one).

Core Endpoints

POST /stream

Stream blockchain data with filters. Includes unfinalized blocks.

POST /finalized-stream

Stream only finalized blocks. Use for production pipelines requiring certainty.

GET /metadata

Get dataset information: block range, finality rules, and network details.

Installation

npm install @subsquid/portal-client

Quick Start Examples

curl --compressed -X POST 'https://portal.sqd.dev/datasets/ethereum-mainnet/stream' \
  -H 'Content-Type: application/json' \
  -d '{
    "type": "evm",
    "fromBlock": 18000000,
    "toBlock": 18001000,
    "fields": {
      "block": { "number": true, "timestamp": true },
      "log": { "address": true, "topics": true, "data": true }
    }
  }'

Available Fields

Block Fields

Select which block header fields to retrieve:

fields: {
  block: {
    number: true,          // Block number
    hash: true,            // Block hash
    parentHash: true,      // Parent block hash
    timestamp: true,       // Unix timestamp
    size: true,            // Block size in bytes
    gasUsed: true,         // Total gas used
    gasLimit: true,        // Gas limit
    baseFeePerGas: true,   // Base fee (EIP-1559)
    stateRoot: true,       // State root hash
    transactionsRoot: true,// Transactions root
    receiptsRoot: true,    // Receipts root
    logsBloom: true,       // Logs bloom filter
    difficulty: true,      // Difficulty
    totalDifficulty: true, // Total difficulty
    miner: true,           // Block producer address
    nonce: true,           // Block nonce
    mixHash: true,         // Mix hash
    extraData: true,       // Extra data
  }
}

Transaction Fields

Select transaction data fields:

fields: {
  transaction: {
    hash: true,            // Transaction hash
    from: true,            // Sender address
    to: true,              // Recipient address (null for deployments)
    value: true,           // ETH value transferred
    input: true,           // Transaction input data
    nonce: true,           // Sender nonce
    gas: true,             // Gas limit
    gasPrice: true,        // Gas price (legacy)
    maxFeePerGas: true,    // Max fee (EIP-1559)
    maxPriorityFeePerGas: true, // Priority fee (EIP-1559)
    gasUsed: true,         // Actual gas used
    cumulativeGasUsed: true, // Cumulative gas in block
    effectiveGasPrice: true, // Effective gas price paid
    status: true,          // Status (1 = success, 0 = failure)
    type: true,            // Transaction type
    chainId: true,         // Chain ID
    v: true,               // Signature V
    r: true,               // Signature R
    s: true,               // Signature S
    yParity: true,         // Y parity (EIP-2930/1559)
    contractAddress: true, // Deployed contract address
    transactionIndex: true,// Index in block
  }
}

Log Fields

Select event log fields:

fields: {
  log: {
    address: true,         // Contract address
    topics: true,          // Event topics (topic0-topic3)
    data: true,            // Event data
    logIndex: true,        // Log index in block
    transactionIndex: true,// Transaction index
    transactionHash: true, // Transaction hash
  }
}

Trace Fields

Select call trace fields:

fields: {
  trace: {
    type: true,            // Trace type (call, delegatecall, etc.)
    from: true,            // Caller address
    to: true,              // Callee address
    value: true,           // Value transferred
    input: true,           // Call input data
    output: true,          // Call output data
    gas: true,             // Gas provided
    gasUsed: true,         // Gas actually used
    error: true,           // Error message (if failed)
    revertReason: true,    // Revert reason (if reverted)
    createResultAddress: true, // Created contract address
    createResultCode: true,    // Created contract code
  }
}

State Diff Fields

Select state change fields:

fields: {
  stateDiff: {
    address: true,         // Contract address
    key: true,             // Storage key
    kind: true,            // Change type (=, +, *, -)
    prev: true,            // Previous value
    next: true,            // New value
  }
}

Filtering Options

Log Filters

Filter logs by contract address and event topics:

logs: [
  {
    address: ["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"], // USDC
    topic0: [
      "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
    ], // Transfer
    topic1: ["0x..."], // Optional: first indexed param
    topic2: ["0x..."], // Optional: second indexed param
    topic3: ["0x..."], // Optional: third indexed param
  },
  // Multiple filter objects = OR logic
  {
    address: ["0x..."],
    topic0: ["0x..."],
  },
];

Filter logic:

Multiple addresses in one object = OR
Multiple topics in one object = AND
Multiple filter objects = OR

Transaction Filters

Filter transactions by sender, recipient, or function signature:

transactions: [
  {
    from: ["0x..."], // Sender addresses
    to: ["0x..."], // Recipient addresses
    sighash: ["0xa9059cbb"], // Function signature (first 4 bytes)
  },
];

Trace Filters

Filter traces by type, caller, or callee:

traces: [
  {
    type: ["call", "delegatecall", "staticcall"],
    callFrom: ["0x..."], // Caller address
    callTo: ["0x..."], // Callee address
    callSighash: ["0x..."], // Function signature
  },
];

State Diff Filters

Filter state changes by contract address:

stateDiffs: [
  {
    address: ["0x..."], // Contract addresses
  },
];

Network Selection

Specify the EVM network when creating the data source:

// Ethereum mainnet
const eth = new DataSource({ network: "ethereum-mainnet" });

// Ethereum testnet
const sepolia = new DataSource({ network: "ethereum-sepolia" });

// Layer 2 networks
const arbitrum = new DataSource({ network: "arbitrum-one" });
const optimism = new DataSource({ network: "optimism-mainnet" });
const base = new DataSource({ network: "base-mainnet" });
const polygon = new DataSource({ network: "polygon-mainnet" });

// Other EVM chains
const bsc = new DataSource({ network: "binance-mainnet" });
const avalanche = new DataSource({ network: "avalanche-mainnet" });

View All Networks

See complete list of 100+ supported EVM networks

Query Patterns

Pattern 1: Range Query

Query a specific block range:

const blocks = await dataSource.getBlocks({
  from: 18000000,
  to: 18100000,
  fields: {
    /* fields */
  },
  logs: [
    /* filters */
  ],
});

Pattern 2: Batch Processing

Process large ranges in batches:

const BATCH_SIZE = 10000;

for (let i = startBlock; i < endBlock; i += BATCH_SIZE) {
  const blocks = await dataSource.getBlocks({
    from: i,
    to: Math.min(i + BATCH_SIZE, endBlock),
    fields: {
      /* fields */
    },
  });

  // Process blocks
  await processBlocks(blocks);
}

Pattern 3: Multi-Contract Query

Query multiple contracts simultaneously:

const blocks = await dataSource.getBlocks({
  from: 18000000,
  to: 18100000,
  fields: {
    log: { address: true, topics: true, data: true },
  },
  logs: [
    {
      address: [
        "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC
        "0xdAC17F958D2ee523a2206206994597C13D831ec7", // USDT
        "0x6B175474E89094C44Da98b954EedeAC495271d0F", // DAI
      ],
      topic0: [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
      ],
    },
  ],
});

Performance Optimization

1. Request Only Needed Fields

// Good: Minimal fields
fields: {
  log: {
    address: true,
    topics: true,
  }
}

// Avoid: Requesting unnecessary fields
fields: {
  log: {
    address: true,
    topics: true,
    data: true,        // Only if needed
    transactionHash: true, // Only if needed
    blockNumber: true,     // Only if needed
  }
}

2. Use Specific Filters

// Good: Filter at Portal level
logs: [
  {
    address: ["0xSpecificContract"],
    topic0: ["0xSpecificEvent"],
  },
];

// Avoid: Fetching everything and filtering in code
logs: []; // Gets all logs

3. Optimal Batch Sizes

// Good: 10k-50k blocks per query for most use cases
const BATCH_SIZE = 10000;

// Adjust based on:
// - More filters = larger batches OK
// - More fields = smaller batches
// - More activity (mainnet) = smaller batches

4. Parallel Queries

// Process multiple ranges in parallel
const ranges = [
  { from: 18000000, to: 18100000 },
  { from: 18100000, to: 18200000 },
  { from: 18200000, to: 18300000 },
];

const results = await Promise.all(
  ranges.map((range) =>
    dataSource.getBlocks({
      from: range.from,
      to: range.to,
      fields: {
        /* fields */
      },
    })
  )
);

Stream continuation

A single /stream response is a batch, not the complete range. The server may close the connection at any point: when a worker’s range ends, when a connection is recycled, or at the current dataset head. Clients that treat one HTTP response as the whole query will silently drop blocks. To stream a range to completion, loop:

async function streamRange(from: number, to: number | undefined, body: any) {
  let currentFrom = from;
  while (to === undefined || currentFrom <= to) {
    const res = await fetch(
      "https://portal.sqd.dev/datasets/ethereum-mainnet/stream",
      {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ ...body, fromBlock: currentFrom, toBlock: to }),
      }
    );

    if (res.status === 204) break; // range is above the dataset head
    if (!res.ok) throw new Error(`HTTP ${res.status}: ${await res.text()}`);

    const lines = (await res.text()).trim().split("\n").filter(Boolean);
    if (lines.length === 0) break;

    let lastBlock = currentFrom - 1;
    for (const line of lines) {
      const block = JSON.parse(line);
      // ... process block ...
      lastBlock = block.header.number;
    }
    currentFrom = lastBlock + 1;
  }
}

Key points:

Read the last block’s header.number, issue the next request with fromBlock = lastNumber + 1.
Keep toBlock, fields, and filters identical across retries.
A 204 No Content response means the range is above the dataset head. For historical queries, you’re done; for open-ended queries, wait and retry.

Handling reorgs near the chain head

When a request starts at or near the chain tip, the block you asked for may no longer be on the canonical chain by the time Portal processes the query. To detect this, pass parentBlockHash with each request (the hash of the block immediately before fromBlock):

const body = {
  type: "evm",
  fromBlock: lastBlock.number + 1,
  parentBlockHash: lastBlock.hash, // hash of lastBlock, i.e. parent of fromBlock
  fields: { block: { number: true, hash: true, parentHash: true } },
  logs: [
    /* filters */
  ],
};

If the chain has reorged away from parentBlockHash, Portal returns HTTP 409 with a list of blocks that are on the current canonical chain:

{
  "previousBlocks": [
    { "number": 24928291, "hash": "0x129bc9..." },
    { "number": 24928290, "hash": "0x8af2be..." }
  ]
}

Client recovery:

Find a block in your local state whose (number, hash) matches one of previousBlocks.
Roll back your pipeline to that block.
Resume the stream with fromBlock = matched.number + 1 and parentBlockHash = matched.hash.

Streams opened against /finalized-stream (instead of /stream) never return 409: only finalized blocks are served, so there’s nothing to reorg. Use that endpoint when you don’t need real-time data.

Error Handling

try {
  const blocks = await dataSource.getBlocks({
    from: 18000000,
    to: 18100000,
    fields: {
      /* fields */
    },
  });
} catch (error) {
  if (error.code === "RATE_LIMIT_EXCEEDED") {
    // HTTP 429: Public Portal rate limit. Honor Retry-After if set.
    console.error("Rate limit exceeded, waiting...");
    await new Promise((resolve) => setTimeout(resolve, 10000));
  } else if (error.code === "CONFLICT") {
    // HTTP 409: chain reorg. See "Handling reorgs near the chain head" above.
    const { previousBlocks } = error.body;
    // Roll back to a common ancestor and resume.
  } else if (error.code === "INVALID_BLOCK_RANGE") {
    // HTTP 400: fromBlock is below the dataset's start_block, or the query is malformed.
    console.error("Invalid block range");
  } else if (error.code === "NETWORK_ERROR") {
    // Transport error, retry with backoff.
    console.error("Network error, retrying...");
  } else {
    // HTTP 500: do not retry. HTTP 503: retry later, honor Retry-After.
    console.error("Unknown error:", error);
  }
}

Common Use Cases

Use Case 1: Event Monitoring

Monitor specific smart contract events:

const blocks = await dataSource.getBlocks({
  from: latestProcessedBlock + 1,
  fields: {
    block: { number: true, timestamp: true },
    log: { address: true, topics: true, data: true },
  },
  logs: [
    {
      address: [CONTRACT_ADDRESS],
      topic0: [EVENT_SIGNATURE],
    },
  ],
});

Use Case 2: Transaction Tracking

Track transactions to/from specific addresses:

const blocks = await dataSource.getBlocks({
  from: startBlock,
  to: endBlock,
  fields: {
    transaction: { hash: true, from: true, to: true, value: true },
  },
  transactions: [
    {
      from: [WATCHED_ADDRESS],
    },
  ],
});

Use Case 3: Analytics Pipeline

Build analytics on blockchain data:

const blocks = await dataSource.getBlocks({
  from: startBlock,
  to: endBlock,
  fields: {
    block: { number: true, timestamp: true, gasUsed: true },
    transaction: { gasUsed: true, value: true },
  },
});

// Aggregate statistics
const stats = blocks.map((block) => ({
  block: block.header.number,
  txCount: block.transactions.length,
  totalGas: block.header.gasUsed,
  totalValue: block.transactions.reduce(
    (sum, tx) => sum + BigInt(tx.value),
    0n
  ),
}));

Request Structure Reference

Every Portal request follows this structure:

{
  type: "evm",              // Chain type
  fromBlock: number,        // Starting block (inclusive)
  toBlock?: number,         // Ending block (inclusive, optional)
  fields: {                 // What data to return
    block?: { ... },
    transaction?: { ... },
    log?: { ... },
    trace?: { ... },
    stateDiff?: { ... }
  },
  logs?: [...],            // Filter by event logs
  transactions?: [...],    // Filter by transactions
  traces?: [...],          // Filter by call traces
  stateDiffs?: [...]       // Filter by state changes
}

Response Format

Portal returns newline-delimited JSON (NDJSON), with one block per line:

{"header": {"number": 18000000, ...}, "logs": [...], "transactions": [...]}
{"header": {"number": 18000001, ...}, "logs": [...], "transactions": [...]}
{"header": {"number": 18000002, ...}, "logs": [...], "transactions": [...]}

This format enables constant-memory streaming of arbitrary ranges.

Common Patterns

Batch Processing

Process large block ranges by splitting into manageable chunks:

const BATCH_SIZE = 10000;
for (let from = startBlock; from < endBlock; from += BATCH_SIZE) {
  const to = Math.min(from + BATCH_SIZE, endBlock);
  const blocks = await fetch(/* ... */);
}

Real-time Streaming

Stream new blocks as they arrive using /finalized-stream:

const response = await fetch(
  'https://portal.sqd.dev/datasets/ethereum-mainnet/finalized-stream',
  { method: 'POST', body: JSON.stringify({
    type: 'evm',
    fromBlock: latestProcessedBlock + 1,
    fields: { /* ... */ }
  })}
);

Error Handling

Handle rate limits and network errors gracefully:

try {
  const response = await fetch(/* ... */);
  if (!response.ok) {
    if (response.status === 429) {
      // Rate limited - wait and retry
      await sleep(10000);
    }
  }
} catch (error) {
  // Network error - implement retry logic
}

Complete API Specification

For the complete OpenAPI specification with all available fields, options, and detailed schemas:

Full EVM API Specification

View complete OpenAPI documentation with all endpoints, fields, and options →

Next Steps

View Examples

Explore practical Portal examples for common use cases

Supported Networks

See complete list of 100+ supported EVM networks

Quickstart Guide

Make your first Portal request in 5 minutes

Overview

Portal API reference

Working with Portal API

Local Setup

Supported Networks

Documentation Index

Complete EVM API Specification

​Base URL

​Core Endpoints

POST /stream

POST /finalized-stream

GET /metadata

​Installation

​Quick Start Examples

​Available Fields

​Block Fields

​Transaction Fields

​Log Fields

​Trace Fields

​State Diff Fields

​Filtering Options

​Log Filters

​Transaction Filters

​Trace Filters

​State Diff Filters

​Network Selection

View All Networks

​Query Patterns

​Pattern 1: Range Query

​Pattern 2: Batch Processing

​Pattern 3: Multi-Contract Query

​Performance Optimization

​1. Request Only Needed Fields

​2. Use Specific Filters

​3. Optimal Batch Sizes

​4. Parallel Queries

​Stream continuation

​Handling reorgs near the chain head

​Error Handling

​Common Use Cases

​Use Case 1: Event Monitoring

​Use Case 2: Transaction Tracking

​Use Case 3: Analytics Pipeline

​Request Structure Reference

​Response Format

​Common Patterns

​Complete API Specification

Full EVM API Specification

​Next Steps

View Examples

Supported Networks

Quickstart Guide

Base URL

Core Endpoints

Installation

Quick Start Examples

Available Fields

Block Fields

Transaction Fields

Log Fields

Trace Fields

State Diff Fields

Filtering Options

Log Filters

Transaction Filters

Trace Filters

State Diff Filters

Network Selection

Query Patterns

Pattern 1: Range Query

Pattern 2: Batch Processing

Pattern 3: Multi-Contract Query

Performance Optimization

1. Request Only Needed Fields

2. Use Specific Filters

3. Optimal Batch Sizes

4. Parallel Queries

Stream continuation

Handling reorgs near the chain head

Error Handling

Common Use Cases

Use Case 1: Event Monitoring

Use Case 2: Transaction Tracking

Use Case 3: Analytics Pipeline

Request Structure Reference

Response Format

Common Patterns

Complete API Specification

Next Steps