Uniswap on-chain data (Ethereum)

Uniswap on-chain data is the set of Swap, Mint (liquidity added), and Burn (liquidity removed) events for every Uniswap V2 and V3 pool on Ethereum mainnet, stored permanently in the public Ethereum blockchain as contract event logs. The data is retrieved by querying a JSON-RPC endpoint with eth_getLogs, filtered by pool contract address and event topic0 signature. No account and no API key are required: the chain state is public. Pools are discovered from the Uniswap factory contracts via their PairCreated (V2) or PoolCreated (V3) events. Used in, for example, Lehar & Parlour (2025), where 95.8 million interactions across 105,098 pools from November 2018 to December 2022 form the primary dataset.

• Cost: free. The Ethereum blockchain is public state.
• API key: none required for the working public endpoints listed below; several commonly cited endpoints now require a key or block archive requests.
• Coverage: Uniswap V2 (launched May 2020, block ~10,000,835) and V3 (launched May 2021, block ~12,369,621); all pools on Ethereum mainnet. Uniswap V1 (launched November 2018) is the earliest version and has a different design (see Gotchas); studies of the early period, including Lehar & Parlour, cover V1 and V2. Historical pulls require an archive node.
• V1 factory: 0xc0a47dFe034B400B47bDaD5FecDa2621de6c4d95
• V2 factory: 0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f
• V3 factory: 0x1F98431c8aD98523631AE4a59f267346ea31F984
• Home: https://uniswap.org

Access

Query any JSON-RPC endpoint with eth_getLogs, specifying the pool contract address and the event topic0 hash. The public endpoint https://eth.drpc.org serves archive getLogs with no key (confirmed 2026-06-22). Use small block windows (20-100 blocks for active pools; see Gotchas).

# Fetch V3 Swap events for the USDC/ETH 0.05% pool over 100 blocks (drpc, no key)
# Pool: 0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640
# V3 Swap topic0: 0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67
curl -s https://eth.drpc.org \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method":  "eth_getLogs",
    "params": [{
      "fromBlock": "0xF42400",
      "toBlock":   "0xF42464",
      "address":   "0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640",
      "topics":    ["0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67"]
    }],
    "id": 1
  }'

Pool addresses are not known in advance; discover them from the factory. To enumerate all V3 pools, query the V3 factory for PoolCreated events using the same eth_getLogs method with the factory address and the PoolCreated topic0. V2 pools are discovered via PairCreated on the V2 factory.

Endpoint status (tested 2026-06-22)

Endpoint	eth_blockNumber	eth_getLogs (archive)	Notes
https://eth.drpc.org	OK	OK	No key. 10,000-block hard cap; data-volume timeout on busy pools around 200 blocks; 20-100 block windows safe. Recommended primary.
https://1rpc.io/eth	OK	OK	No key. Returns identical logs. Good failover.
https://ethereum-rpc.publicnode.com	OK	Blocked	Returns “Archive requests require a personal token” on getLogs.
https://eth-mainnet.public.blastapi.io	OK	Severely capped	10-block range cap; impractical for backfill.
https://rpc.ankr.com/eth	Requires key	Requires key	Key required as of 2026-06.
https://cloudflare-eth.com	Dead	Dead	Returns -32046.
https://eth.llamarpc.com	Down	Down	HTTP 521.

Gotchas (the ones that bite pipelines)

• Most well-known public RPCs do not serve archive getLogs. Several endpoints that appear in tutorials return eth_blockNumber fine but reject eth_getLogs on archive blocks with “archive request requires token” or fail silently (cloudflare: -32046; llamarpc: 521; ankr: requires key). Test the actual getLogs call against a known old block, not just connectivity. Hard-code drpc plus 1rpc as the working pair and implement failover.
• Block-range limits are twofold. There is a hard block-count cap (drpc: 10,000 blocks; blastapi: 10 blocks) and a separate data-volume timeout (on drpc, a high-activity pool like USDC/ETH 0.05% times out around 200 blocks; 20-100 blocks is safe). Page in small windows and implement exponential back-off on timeouts. A chunker that iterates across windows is required for any historical backfill.
• Uniswap V1 is not V2 or V3, and this page’s topic0 hashes and decoding are V2/V3 only. The Lehar & Parlour sample begins at V1 launch (November 2018); V1 predates the factory-of-pairs design. Each ERC-20 token has its own Vyper exchange contract, discovered from the V1 factory (0xc0a47dFe034B400B47bDaD5FecDa2621de6c4d95) via its NewExchange event. V1 trades emit TokenPurchase and EthPurchase (not Swap) and liquidity events AddLiquidity and RemoveLiquidity (not Mint / Burn). Read the event ABI from a V1 exchange contract before decoding; do not reuse the V2/V3 signatures below for V1 logs.
• V2 and V3 ABI schemas differ substantially; do not share a decoder. V2 Swap has four unsigned amounts (amount0In, amount1In, amount0Out, amount1Out); price is inferred from the reserve state via the Sync event. V3 Swap has signed amount0 and amount1 (negative = flowing out of the pool) plus sqrtPriceX96, liquidity, and tick; price is (sqrtPriceX96 / 2**96)**2 adjusted for the decimal difference between the two tokens. V3 Mint and Burn carry tickLower and tickUpper for the concentrated-liquidity range, which V2 does not have. Indexed event parameters (sender, owner, recipient) come from topics[1] and topics[2], not from the data field.
• Historical backfill requires archive access. V2 launched at block ~10,000,835 (May 2020) and V3 at block ~12,369,621 (May 2021). Fetching those early blocks requires an archive node. drpc serves archive getLogs without a key (confirmed at block 12,380,000). A full backfill across all pools is large; discover pools from the factory first, then run per-pool windowed scans.
• Reorgs near the chain tip. Do not treat the most recent blocks as final. Lag at least 64 blocks from the tip, or wait for the finalized tag. Tag each event with blockNumber, transactionHash, and logIndex as a composite key, and re-fetch the trailing window after each run to self-heal rows from reorged blocks.
• Token amounts are raw integers. Divide by 10**decimals per token before using values: USDC uses 6 decimals, WETH uses 18. Fetch decimals from the token contract’s decimals() view function or from a maintained token list. Always confirm a pool address came from the correct factory (V2 vs V3) before trusting its events.

Reference

Factory contracts

Protocol	Factory address	Pool discovery event
Uniswap V1	0xc0a47dFe034B400B47bDaD5FecDa2621de6c4d95	NewExchange(address,address) (per-token Vyper exchange; V1 ABI differs, see Gotchas)
Uniswap V2	0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f	PairCreated(address,address,address,uint256)
Uniswap V3	0x1F98431c8aD98523631AE4a59f267346ea31F984	PoolCreated(address,address,uint24,int24,address)

Event topic0 signatures (keccak256 of the event signature string)

Protocol	Event	topic0
V2	Swap(address,uint256,uint256,uint256,uint256,address)	0xd78ad95fa46c994b6551d0da85fc275fe613ce37657fb8d5e3d130840159d822
V2	Mint(address,uint256,uint256)	0x4c209b5fc8ad50758f13e2e1088ba56a560dff690a1c6fef26394f4c03821c4f
V2	Burn(address,uint256,uint256,address)	0xdccd412f0b1252819cb1fd330b93224ca42612892bb3f4f789976e6d81936496
V3	Swap(address,address,int256,int256,uint160,uint128,int24)	0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67
V3	Mint(address,address,int24,int24,uint128,uint256,uint256)	0x7a53080ba414158be7ec69b987b5fb7d07dee101fe85488f0853ae16239d0bde
V3	Burn(address,int24,int24,uint128,uint256,uint256)	0x0c396cd989a39f4459b5fa1aed6a9a8dcdbc45908acfd67e028cd568da98982c

V2 vs V3 decoding summary

Aspect	V2	V3
Swap amount fields	Unsigned: amount0In, amount1In, amount0Out, amount1Out	Signed: amount0, amount1 (negative = out of pool)
Price in Swap	Not present; infer from Sync(reserve0,reserve1)	sqrtPriceX96; price = (sqrtPriceX96/2^96)^2 x decimal adjustment
Liquidity range	Full range only	Concentrated: tickLower, tickUpper in Mint/Burn
Indexed params in topics	sender (Swap, Mint/Burn)	sender + recipient (Swap); owner + ticks (Mint/Burn)
Key required	No	No

Citation

Cite the Ethereum blockchain as the primary source, specifying the Uniswap V2 or V3 core contracts (with factory address), the pool address(es) queried (with token pair and fee tier for V3), the block range covered, the RPC endpoint used, and the retrieval date. If data were obtained via a derived or aggregated product (such as The Graph subgraph or Dune Analytics), cite that layer separately and note the underlying source. Example for a V3 pull:

Uniswap V3 core contracts (factory 0x1F98431c8aD98523631AE4a59f267346ea31F984), Ethereum mainnet. Swap events fetched via eth_getLogs from https://eth.drpc.org, blocks [from]-[to], retrieved [date]. Pool: USDC/WETH 0.05% (0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640).