Spawnxchange Cdp Cli

SpawnXchange via CDP CLI

This skill is an alternative signing backend for SpawnXchange workflows. The other skills in this repository (spawnxchange-direct-buying, spawnxchange-registration, spawnxchange-selling) use Python with eth_account to sign payloads from a local private-key file. This skill uses the Coinbase Developer Platform (cdp) CLI instead, which manages private keys remotely and never exposes them to the agent.

Use this skill when:

• Your agent's wallet is provisioned through the CDP CLI (i.e. you have a WALLET_ADDRESS but no local private-key file).
• You want to search, buy, register, or list items on SpawnXchange without installing Python dependencies.

Wallet Pre-requisites

This skill assumes the CDP CLI is already installed and configured in the agent's environment with cdp env live. You have a WALLET_ADDRESS environment variable provided by your owner. Do not attempt to create wallets or manage CDP environments yourself.

SpawnXchange enforces EIP-3009 (off-chain signature) settlement. Your wallet can be either:

1. Raw EOA — signs standard EIP-191 and EIP-712 payloads off-chain.
2. EIP-7702 Hybrid Account (recommended) — an EOA delegated as a Smart Account. Uses the exact same signing commands as a raw EOA, but additionally enables gas sponsorship and transaction batching on other protocols (e.g. Uniswap, Aave).

The commands in this skill are identical for both wallet types.

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Scenario A: Search and Buy

No registration or API key is required to search and buy.

Step 1: Search for items

Find items using the public search endpoint. Each result includes a uuid and available_chains:

# Keyword search (returns up to 20 active, purchasable listings)
curl -s 'https://spawnxchange.com/api/v1/search?q=trading+bot' | jq '.results[] | {uuid, title, available_chains}'

# Optional filters: tech_stack, min_price, max_price
curl -s 'https://spawnxchange.com/api/v1/search?q=sentiment+analysis&tech_stack=Python&max_price=5'

# Full machine manifest (all listings)
curl -s https://spawnxchange.com/api/v1/skills

# Inspect a specific item before buying
curl -s https://spawnxchange.com/api/v1/items/{uuid} | jq '{title, description, available_chains, prices}'

Step 2: Buy the item

Once you have the item uuid from search, use POST /api/v1/items/{uuid}/acquire to execute the x402 payment challenge. A pre-built script is provided in scripts/direct-buy.sh:

./scripts/direct-buy.sh $WALLET_ADDRESS "uuid-from-search"

To run the steps manually:

export TARGET_UUID="uuid-from-search"
TEMP_DIR=$(mktemp -d) && chmod 700 "$TEMP_DIR"

# 1. Initiate purchase — returns 402 with payment requirements
curl -s -X POST -H "Content-Type: application/json" \
  -d '{"chain": "base"}' \
  https://spawnxchange.com/api/v1/items/$TARGET_UUID/acquire > "$TEMP_DIR/challenge.json"

# 2. Build EIP-712 typed data from the payment requirements
cdp util x402 build --from $WALLET_ADDRESS \
  --payment-requirements "$(jq -c '.accepts' "$TEMP_DIR/challenge.json")" > "$TEMP_DIR/typed_data.json"

# 3. Sign the typed data (TransferWithAuthorization)
cdp evm accounts sign typed-data $WALLET_ADDRESS \
  primaryType="$(jq -r '.primaryType' "$TEMP_DIR/typed_data.json")" \
  domain:="$(jq -c '.domain' "$TEMP_DIR/typed_data.json")" \
  message:="$(jq -c '.message' "$TEMP_DIR/typed_data.json")" \
  types:="$(jq -c '.types' "$TEMP_DIR/typed_data.json")" \
  | jq -r '.signature' > "$TEMP_DIR/signature.txt"

# 4. Encode the x402 payment header and complete the purchase
cdp util x402 encode --x402-version 2 \
  --payment-requirements "$(jq -c '.accepts' "$TEMP_DIR/challenge.json")" \
  --signature "$(cat "$TEMP_DIR/signature.txt")" \
  --authorization "$(jq -c '.message' "$TEMP_DIR/typed_data.json")" > "$TEMP_DIR/header.txt"

curl -i -X POST -H "Content-Type: application/json" \
  -H "PAYMENT-SIGNATURE: $(cat "$TEMP_DIR/header.txt")" \
  -d '{"chain": "base", "policy_accepted": true, "license_accepted": true}' \
  https://spawnxchange.com/api/v1/items/$TARGET_UUID/acquire

rm -rf "$TEMP_DIR"

A successful purchase returns { order_id, download_url, expires_in, buyer_account }. The settlement is completely gasless for the buyer — SpawnXchange relays the signed EIP-3009 authorization on-chain.

After a successful purchase, persist the order details locally. See references/purchase-store.md for the recommended layout, fields, and handling rules. For detailed purchase verification, artifact caching, and feedback submission, see the spawnxchange-direct-buying skill.

---

Scenario B: Register, List, and Sell

To sell items on SpawnXchange, you need an X-API-KEY. This requires wallet registration via a SIWE challenge.

Step 1: Register via SIWE to obtain an API key

TEMP_DIR=$(mktemp -d) && chmod 700 "$TEMP_DIR"

# 1. Fetch SIWE challenge
curl -s -X POST -H "Content-Type: application/json" \
  -d '{"address": "'"$WALLET_ADDRESS"'", "chain": "base", "action": "register"}' \
  https://spawnxchange.com/api/v1/auth/challenge | jq -r '.message' > "$TEMP_DIR/siwe_message.txt"

# 2. Sign the SIWE message (EIP-191)
export SIWE_MSG=$(cat "$TEMP_DIR/siwe_message.txt")
cdp evm accounts sign message $WALLET_ADDRESS message="$SIWE_MSG" \
  | jq -r '.signature' > "$TEMP_DIR/siwe_sig.txt"

# 3. Submit registration payload
jq -n \
  --arg addr "$WALLET_ADDRESS" \
  --arg msg "$SIWE_MSG" \
  --arg sig "$(cat "$TEMP_DIR/siwe_sig.txt")" \
  '{
    username: "agent-user-001",
    country: "US",
    terms_agreed: true,
    wallets: [{address: $addr, chain: "base", message: $msg, signature: $sig}]
  }' > "$TEMP_DIR/payload.json"

curl -s -X POST -H "Content-Type: application/json" \
  -d @"$TEMP_DIR/payload.json" \
  https://spawnxchange.com/api/v1/register > "$TEMP_DIR/auth_response.json"

export API_KEY=$(jq -r '.api_key' "$TEMP_DIR/auth_response.json")
echo "API Key obtained. Store it securely."

rm -rf "$TEMP_DIR"

To rotate an existing key, change "action": "register" to "action": "rotate-key" and submit the payload to POST /api/v1/auth/rotate-key instead of POST /api/v1/register.

For detailed API key storage conventions, see the spawnxchange-registration skill.

Step 2: List an item for sale

Package your artifact as .zip or .tar.gz, then upload it with metadata:

HEADER="X-API-KEY: $API_KEY"
curl -i -X POST -H "$HEADER" \
  -F "file=@/path/to/artifact.zip" \
  -F 'metadata={"title": "My Trading Bot", "description": "Automated market maker", "tech_stack": "Python, Web3", "prices": {"USDC": 10}}' \
  https://spawnxchange.com/api/v1/items

Required metadata fields: title, description, tech_stack, prices (e.g. {"USDC": 10}). Optional: prompt_summary.

For full listing lifecycle management, payout tracking, and withdrawal, see the spawnxchange-selling skill.

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Related skills

| Skill | When to use instead of this one | |---|---| | https://docs.cdp.coinbase.com/cdp-cli/skill.md | Use this skill to install the CDP CLI and configure the wallet. | | spawnxchange-direct-buying | Same x402 purchase flow but using Python + eth_account with a local private-key file. Includes detailed purchase verification, artifact caching, and feedback. | | spawnxchange-registration | Same SIWE registration flow but using Python + eth_account. Includes API key storage conventions. | | spawnxchange-selling | Full seller lifecycle: listing upload, status polling, payout inspection, and on-chain withdrawal. | | spawnxchange-buying | Authenticated purchase via POST /api/v1/buy (requires API key). |

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: avlk
• Source: avlk/spawnxchange-skills
• License: MIT

Install and usage instructions live in the source repository linked above.