Get mempool snapshot

Returns a snapshot of the Polygon mempool: every transaction the node has accepted but not yet included in a block. Results are split into two arrays — pending (transactions executable right now, i.e. the nonce is next in line for the sender) and queued (transactions parked behind a nonce gap and not yet executable). Each entry is a PolyPendingTx with the sender, recipient, nonce, and gas-pricing fields.

The snapshot also reports observed_at (the instant it was captured) and block_height (the chain head at that instant), so you can correlate the pool state against a specific block.

Use this endpoint for one-shot mempool inspection: gas-price estimation, nonce reconciliation for a pending send, or detecting whether a broadcast transaction has reached the pool. For a continuous stream of pending transactions, use the mempool firehose connect-info endpoint instead (see Notes); for aggregate counts and gas percentiles, see Get mempool stats.

This is the only Polygon mempool access available on the free underlying canal — the upstream pool view is a scarce resource, which is why the endpoint is gated at Pro and is rate-limited per tier. Snapshots can be large on a busy chain; use the limit parameter to cap the number of entries returned per array.

Query parameters

Response fields

PolyPendingTx

Example 403 body (tier below Pro):

{
  "error": "tier_insufficient",
  "message": "polygon_mempool requires the pro tier",
  "request_id": "req_8c1d2e3f4a5b",
  "current_tier": "basic",
  "required_tier": "pro",
  "category": "polygon_mempool",
  "method": "polygonMempoolSnapshot",
  "upgrade_url": "https://api.triport.io/billing/upgrade"
}

Example 429 body:

{
  "error": "rate_limited",
  "message": "rate limit exceeded on polygon_mempool",
  "request_id": "req_a1b2c3d4e5f6",
  "current_tier": "pro",
  "category": "polygon_mempool",
  "retry_after_sec": 1,
  "limit_rps": 25,
  "burst_capacity": 50
}

429 responses also carry Retry-After, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, and X-RateLimit-Category headers. See the shared error reference for the full envelope and every error code.

JavaScript (fetch)

const res = await fetch(
  "https://api.triport.io/v1/polygon/mempool/snapshot?limit=100",
  { headers: { Authorization: `Bearer ${process.env.TRIPORT_API_KEY}` } }
);
if (!res.ok) throw new Error(`HTTP ${res.status}`);


const snapshot = await res.json();
console.log(`@block ${snapshot.block_height}: ` +
  `${snapshot.pending.length} pending, ${snapshot.queued.length} queued`);

TypeScript SDK (@triport/sdk)

import { Triport } from "@triport/sdk";


const client = new Triport({ apiKey: process.env.TRIPORT_API_KEY! });


const snapshot = await client.polygon.mempool.snapshot({ limit: 100 });


for (const tx of snapshot.pending) {
  console.log(`${tx.hash} from ${tx.from} (nonce ${tx.nonce})`);
}

Python (triport-sdk)

import os
from triport import Triport


client = Triport(api_key=os.environ["TRIPORT_API_KEY"])


snapshot = client.polygon.mempool.snapshot(limit=100)


print(f"@block {snapshot.block_height}: "
      f"{len(snapshot.pending)} pending, {len(snapshot.queued)} queued")

• limit caps each array independently — a request with limit=50 can return up to 50 pending and up to 50 queued entries.
• A transaction in queued is waiting on an earlier nonce from the same sender; it becomes executable (and moves to pending) once the gap is filled.
• For EIP-1559 transactions, read max_fee_per_gas_wei / max_priority_fee_per_gas_wei; gas_price_wei will be "0" or empty. For legacy transactions, the reverse holds.
• The snapshot is a single point in time — the pool changes every block. For a live stream, request a signed WebSocket URL from the mempool firehose connect-info endpoint (Business tier). For rolling aggregates instead of raw entries, see Get mempool stats.