feat: add SwapAPI skill for DEX-aggregated token swaps on 40+ evm networks

swap-api/SKILL.md

@@ -0,0 +1,150 @@
+---
+name: swapapi
+metadata:
+  {
+    "bankr":
+      {
+        "emoji": "🔄",
+        "homepage": "https://api.swapapi.dev",
+        "requires": { "bins": ["curl"] },
+      },
+  }
+---
+
+# SwapAPI
+
+Get executable token swap calldata for any EVM chain via HTTP API. Free, no API keys required.
+
+## Quick Start
+
+Swap 0.001 ETH for USDC on Base:
+
+```bash
+curl "https://api.swapapi.dev/v1/swap/8453?\
+tokenIn=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE&\
+tokenOut=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913&\
+amount=1000000000000000&\
+sender=0xYourAddress"
+```
+
+Returns transaction data ready to sign and broadcast:
+
+```json
+{
+  "success": true,
+  "data": {
+    "status": "Successful",
+    "tx": {
+      "to": "0x...",
+      "data": "0x...",
+      "value": "1000000000000000",
+      "gas": "150000"
+    },
+    "expectedAmountOut": "2435120",
+    "minAmountOut": "2422947"
+  }
+}
+```
+
+## Supported Chains
+
+| Chain ID | Chain | Native Token |
+|----------|-------|--------------|
+| 1 | Ethereum | ETH |
+| 8453 | Base | ETH |
+| 42161 | Arbitrum | ETH |
+| 137 | Polygon | MATIC |
+| 10 | Optimism | ETH |
+| 56 | BSC | BNB |
+| 43114 | Avalanche | AVAX |
+
+...and 40+ more. See [references/chains.md](references/chains.md) for full list.
+
+## API Reference
+
+**Endpoint:** `GET /v1/swap/{chainId}`
+
+**Parameters:**
+
+| Param | Required | Description |
+|-------|----------|-------------|
+| `chainId` | path | Chain ID (e.g., 8453 for Base) |
+| `tokenIn` | query | Input token address. Use `0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE` for native ETH |
+| `tokenOut` | query | Output token address |
+| `amount` | query | Input amount in smallest unit (wei for ETH) |
+| `sender` | query | Your wallet address |
+| `maxSlippage` | query | Optional. 0-1 (default: 0.005 = 0.5%) |
+
+**Response codes:**
+- `200` — Quote ready
+- `400` — Invalid params or unsupported chain
+- `429` — Rate limit (60/min per IP)
+
+## Native Token Address
+
+Use `0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE` for:
+- ETH (Ethereum, Base, Arbitrum, Optimism)
+- MATIC (Polygon)
+- BNB (BSC)
+- AVAX (Avalanche)
+
+Always 18 decimals.
+
+## Common Token Addresses
+
+| Token | Address (Base) |
+|-------|----------------|
+| USDC | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` |
+| USDbC | `0xd9aAEc86B65D86f6A7B5B1d0c0c41515Da3f5F0` |
+| cbETH | `0x2Ae3F1Ec7F1F5012CFEab0185bfc7aa3cf0DEc22` |
+| WETH | `0x4200000000000000000000000000000000000006` |
+
+## Example: ETH → USDC on Base
+
+```bash
+# 1. Get swap quote
+RESPONSE=$(curl -s "https://api.swapapi.dev/v1/swap/8453?\
+tokenIn=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE&\
+tokenOut=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913&\
+amount=1000000000000000&\
+sender=$SENDER")
+
+# 2. Parse transaction fields
+TX_TO=$(echo "$RESPONSE" | jq -r '.data.tx.to')
+TX_DATA=$(echo "$RESPONSE" | jq -r '.data.tx.data')
+TX_VALUE=$(echo "$RESPONSE" | jq -r '.data.tx.value')
+TX_GAS=$(echo "$RESPONSE" | jq -r '.data.tx.gas')
+EXPECTED_OUT=$(echo "$RESPONSE" | jq -r '.data.expectedAmountOut')
+
+# 3. Sign and send (using cast)
+cast send \
+  --rpc-url "https://mainnet.base.org" \
+  --private-key "$PRIVATE_KEY" \
+  "$TX_TO" \
+  --value "$TX_VALUE" \
+  --gas-limit "$TX_GAS" \
+  --data "$TX_DATA"
+```
+
+## Pre-flight Checklist
+
+Before executing any swap:
+
+1. **ERC-20 Approval** — If `tokenIn` is not native, ensure approval: `token.approve(router, amount)`
+2. **Balance Check** — Native: `balance >= tx.value`, ERC-20: `balanceOf(sender) >= amountIn`
+3. **Gas Estimation** — Call `eth_estimateGas`, add 20% buffer
+4. **Simulation** — Run `eth_call` to verify no revert
+5. **Timing** — Submit within 30s (calldata expires)
+
+## Scripts
+
+See [scripts/](scripts/) for helper utilities:
+
+- `swap.sh` — Interactive swap CLI
+- `quote.sh` — Get quote only
+
+## Resources
+
+- **API Docs**: https://api.swapapi.dev
+- **GitHub**: https://github.com/swap-api/swap-api
+- **OpenAPI**: https://github.com/swap-api/swap-api/blob/main/openapi.json

swap-api/scripts/quote.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# Get swap quote from SwapAPI
+
+set -e
+
+CHAIN_ID=$1
+TOKEN_IN=$2
+TOKEN_OUT=$3
+AMOUNT=$4
+SENDER=$5
+
+if [ -z "$CHAIN_ID" ] || [ -z "$TOKEN_IN" ] || [ -z "$TOKEN_OUT" ] || [ -z "$AMOUNT" ] || [ -z "$SENDER" ]; then
+    echo "Usage: $0 <chainId> <tokenIn> <tokenOut> <amount> <sender>"
+    echo "Example: $0 8453 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 1000000000000000 0xYourAddress"
+    exit 1
+fi
+
+curl -s "https://api.swapapi.dev/v1/swap/${CHAIN_ID}?tokenIn=${TOKEN_IN}&tokenOut=${TOKEN_OUT}&amount=${AMOUNT}&sender=${SENDER}" | jq .

swap-api/scripts/swap.sh

@@ -0,0 +1,62 @@
+#!/bin/bash
+# Interactive swap helper for SwapAPI
+
+set -e
+
+echo "🔄 SwapAPI Swap Helper"
+echo ""
+
+# Get user input
+read -p "Chain ID (8453=Base, 1=Ethereum, 42161=Arbitrum): " CHAIN_ID
+read -p "Token In (0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE for ETH): " TOKEN_IN
+read -p "Token Out: " TOKEN_OUT
+read -p "Amount (in wei/smallest unit): " AMOUNT
+read -p "Sender Address: " SENDER
+
+echo ""
+echo "Fetching quote..."
+echo ""
+
+RESPONSE=$(curl -s "https://api.swapapi.dev/v1/swap/${CHAIN_ID}?tokenIn=${TOKEN_IN}&tokenOut=${TOKEN_OUT}&amount=${AMOUNT}&sender=${SENDER}")
+
+# Check if successful
+if [ "$(echo "$RESPONSE" | jq -r '.success')" != "true" ]; then
+    echo "❌ Error:"
+    echo "$RESPONSE" | jq .
+    exit 1
+fi
+
+# Display quote
+STATUS=$(echo "$RESPONSE" | jq -r '.data.status')
+EXPECTED_OUT=$(echo "$RESPONSE" | jq -r '.data.expectedAmountOut')
+MIN_OUT=$(echo "$RESPONSE" | jq -r '.data.minAmountOut')
+PRICE_IMPACT=$(echo "$RESPONSE" | jq -r '.data.priceImpact')
+
+echo "✅ Quote received (Status: $STATUS)"
+echo "Expected output: $EXPECTED_OUT"
+echo "Minimum output: $MIN_OUT"
+echo "Price impact: $PRICE_IMPACT"
+echo ""
+
+# Display transaction data
+TX_TO=$(echo "$RESPONSE" | jq -r '.data.tx.to')
+TX_DATA=$(echo "$RESPONSE" | jq -r '.data.tx.data')
+TX_VALUE=$(echo "$RESPONSE" | jq -r '.data.tx.value')
+TX_GAS=$(echo "$RESPONSE" | jq -r '.data.tx.gas')
+
+echo "Transaction Data:"
+echo "  To: $TX_TO"
+echo "  Value: $TX_VALUE"
+echo "  Gas: $TX_GAS"
+echo "  Data: ${TX_DATA:0:50}..."
+echo ""
+
+# Save to file
+OUTPUT_FILE="/tmp/swap_${CHAIN_ID}_$(date +%s).json"
+echo "$RESPONSE" | jq '.data.tx' > "$OUTPUT_FILE"
+echo "💾 Transaction saved to: $OUTPUT_FILE"
+echo ""
+echo "Next steps:"
+echo "  1. Review the transaction data"
+echo "  2. If tokenIn is ERC-20, ensure approval is set"
+echo "  3. Sign and broadcast using cast, viem, or your wallet"