| name | swap |
| description | Swap tokens on the chains the Obol Stack supports — USDC, WETH/ETH, and OBOL on Base and Ethereum mainnet via Uniswap V3. Use when earnings need converting (USDC → ETH for gas, consolidating USDC/OBOL revenue, rebalancing the agent treasury) or the user says 'swap', 'convert', 'sell my USDC', 'get ETH for gas'. Quote first, bound slippage, confirm with the user before sending. |
| metadata | {"openclaw":{"emoji":"🔁","requires":{"bins":["cast","python3"]}}} |
Swap
Convert tokens the agent actually earns and spends. The x402 rails pay you
in USDC on Base or OBOL on Ethereum mainnet; on-chain writes need
ETH for gas (on mainnet — Base writes cost fractions of a cent). This
skill covers the treasury moves between them using Uniswap V3, with quotes
from QuoterV2 and execution through the agent's remote-signer
(ethereum-local-wallet skill).
Iron rules — no exceptions:
- Quote before every swap. Never send a swap without a fresh QuoterV2
quote and an
amountOutMinimum derived from it.
- Confirm with the user before sending any swap, stating: amount in,
expected amount out, minimum out, fee tier, chain. Never swap autonomously.
- Never swap more than the immediate need (e.g. gas top-ups: swap for
~2–4 weeks of expected gas, not the whole balance).
- Addresses below were verified on-chain (
eth_getCode) on 2026-07-06.
Re-verify with rpc.sh code <addr> if anything reverts unexpectedly.
Verified addresses
| Contract | Base (8453) | Ethereum mainnet (1) |
|---|
| Uniswap V3 SwapRouter02 | 0x2626664c2603336E57B271c5C0b26F421741e481 | 0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45 |
| Uniswap V3 QuoterV2 | 0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a | 0x61fFE014bA17989E743c5F6cB21bF9697530B21e |
| USDC (6 decimals) | 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 | 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 |
| WETH (18 decimals) | 0x4200000000000000000000000000000000000006 | 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 |
| OBOL (18 decimals) | — (Base-Sepolia only, no mainnet-Base deploy) | 0x0B010000b7624eb9B3DfBC279673C76E9D29D5F7 |
Aerodrome (router 0xcF77a3Ba9A5CA399B7c97c74d54e5b1Beb874E43, Base) often
has deeper liquidity for long-tail Base pairs — but its ve(3,3) router ABI
differs; prefer Uniswap V3 for the pairs above and reach for Aerodrome only
when V3 quotes are bad. See building-blocks for Aerodrome details.
Recipe: USDC → ETH for gas (Base example)
Environment (same defaults as ethereum-local-wallet):
SKILLS="${OBOL_SKILLS_DIR:-/data/.openclaw/skills}"
RPC="$SKILLS/ethereum-networks/scripts/rpc.sh"
WALLET="$SKILLS/ethereum-local-wallet/scripts/signer.py"
NET=base
ROUTER=0x2626664c2603336E57B271c5C0b26F421741e481
QUOTER=0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a
USDC=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
WETH=0x4200000000000000000000000000000000000006
ME=$(python3 "$WALLET" accounts | grep -o '0x[0-9a-fA-F]*' | head -1)
Step 1 — Quote (read-only, free)
QuoterV2 is called via eth_call even though it's not marked view:
AMOUNT_IN=10000000
sh "$RPC" --network $NET call $QUOTER \
"quoteExactInputSingle((address,address,uint256,uint24,uint160))(uint256,uint160,uint32,uint256)" \
"($USDC,$WETH,$AMOUNT_IN,500,0)"
Try fee tiers 500, 3000, 10000 and keep the best output. A revert
means no pool at that tier — if all tiers revert there is no direct pool;
route through WETH in two hops or stop and tell the user.
Sanity-check the quote against an independent price source if available. A
quote > 2% away from the expected market rate means thin liquidity — warn
the user and reduce size or abort.
Step 2 — Approve the router (once per token per chain)
DATA=$(cast calldata "approve(address,uint256)" $ROUTER $AMOUNT_IN)
python3 "$WALLET" send-tx --from $ME --to $USDC --data $DATA --network $NET
Approve only the amount being swapped (not unlimited).
Step 3 — Swap with a slippage floor
amountOutMinimum = quoted output × 0.995 (0.5% slippage; use 0.3% for
USDC/WETH majors, up to 1% for thin pairs — never 0):
MIN_OUT=<quoted_out * 995 / 1000>
DATA=$(cast calldata \
"exactInputSingle((address,address,uint24,address,uint256,uint256,uint160))" \
"($USDC,$WETH,500,$ME,$AMOUNT_IN,$MIN_OUT,0)")
python3 "$WALLET" send-tx --from $ME --to $ROUTER --data $DATA --network $NET
Step 4 — Unwrap WETH → ETH (if the goal is gas)
DATA=$(cast calldata "withdraw(uint256)" <weth_amount>)
python3 "$WALLET" send-tx --from $ME --to $WETH --data $DATA --network $NET
Step 5 — Verify
sh "$RPC" --network $NET balance $ME
sh "$RPC" --network $NET call $USDC "balanceOf(address)(uint256)" $ME
Variations
- OBOL ↔ ETH/USDC (mainnet): same recipe with
NET=mainnet, mainnet
router/quoter/token addresses. Quote all three fee tiers first — OBOL
liquidity is concentrated in few pools; do not assume a direct
OBOL/USDC pool exists. If direct quotes revert, two-hop via WETH:
quote OBOL→WETH and WETH→USDC separately, execute as two swaps, and
re-confirm with the user before the second hop.
- Mainnet gas cost check: before any mainnet swap run
python3 "$WALLET" gas-info --network mainnet. If the swap gas cost
exceeds ~1% of the swap value, tell the user and suggest batching later.
- Exact output (e.g. "get me exactly 0.01 ETH"): use
quoteExactOutputSingle / exactOutputSingle with the same struct shapes
(amountOut + amountInMaximum instead); approve amountInMaximum.
When NOT to use this skill
- Paying for an x402 service — that's
buy-x402 (no swap needed; it signs
USDC/OBOL authorizations directly).
- Bridging between chains — this skill never bridges. USDC on Base and USDC
on mainnet are different balances; say so if the user conflates them.
- Anything the user hasn't confirmed. Every swap is user-confirmed, every time.
