ChatGPT — Custom GPT Actions
Create a Custom GPT that can query live Cardano blockchain data using NACHO API Actions.
Create a Custom GPT with Actions powered by the NACHO API OpenAPI spec. Your GPT will answer questions about stake pools, transactions, addresses, network stats, and governance using live on-chain data.
Setup steps
1. Open the Custom GPT editor
Go to chat.openai.com → your profile → My GPTs → Create a GPT → Configure tab.
2. Import Actions from OpenAPI spec
Click Add actions → Import from URL and enter:
https://app.nacho.builders/openapi.yamlOpenAI will import all 15 API endpoints as actions automatically.
3. Configure authentication
In the Actions authentication dialog:
- Auth type: API Key
- Header name:
apikey - API key: Your NACHO API key (
napi_xxx)
Free account includes a free API key.
Sign up at https://app.nacho.builders — your API key is created automatically. The free tier covers all standard and explorer actions within rate limits.
4. Paste the system prompt
In the Instructions field, paste:
You are a Cardano blockchain assistant powered by the NACHO API.
You can look up live data including:
- Stake pool information (fees, stake, block production, saturation)
- Stake account delegation status and rewards
- Transaction confirmation status and full transaction details
- Block details and recent block history
- Address balances, UTxOs, and token holdings
- Network statistics (epoch, circulating supply, active stake)
- ADA/USD price and Cardano protocol parameters
- Governance DReps (decentralized representatives)
Response rules:
- ADA amounts from the API are in lovelace (1 ADA = 1,000,000 lovelace). Always convert to ADA when displaying to users.
- Pool margin is a 0-1 decimal. Display as a percentage (0.01 = "1%").
- Default to mainnet. Only use preprod if the user mentions testnet or preprod.
- For addresses starting with "stake1" or "stake_test1", use getStakeAccount. For regular addresses (addr1...), use getAddress.
- Never fabricate pool tickers, transaction hashes, or addresses. Always fetch live data.
- All lovelace amounts are strings in API responses — this is intentional for precision.5. Set privacy policy URL
OpenAI requires a privacy policy URL for Actions:
https://app.nacho.builders/privacyAvailable actions (15)
| Action | What it does |
|---|---|
getPrice | ADA/USD exchange rate |
getProtocolParameters | Current network parameters |
getPoolStatus | NACHO pool live stats |
getPoolInfo | Any pool's metadata and fees |
getStakeAccount | Delegation status and rewards |
getTxStatus | Transaction confirmation status |
getNetworkStats | Epoch, supply, active stake |
getBlocks | Recent blocks list |
getBlock | Block by number or hash |
getTransaction | Full transaction details |
getAddress | Address balance and token counts |
getAddressUtxos | Address UTxO list |
getPoolDetail | Full pool details with relays |
getDReps | Governance DRep list |
graphqlQuery | Custom GraphQL queries over the full DB-Sync schema (all tiers) |
Example questions for your GPT
- "What is NACHO pool's current margin and how many blocks has it minted?"
- "Is transaction 3a9f... confirmed? How many confirmations?"
- "What epoch are we in and how much of it has passed?"
- "Show me the top DReps by voting power on mainnet"
- "What's the ADA price right now?"
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