Authentication
How AI agents authenticate against Tatum: pass your API key in the x-api-key header on every request. No OAuth flow. Where to store keys for MCP, apps, and CI.
API key
Send your key in the x-api-key header on every request. No OAuth flow.
GET /v4/data/wallet/portfolio?address=0x...&chain=ethereum-mainnet
Host: api.tatum.io
x-api-key: tatum_xxxEnvironment
Use TATUM_API_KEY in your shell, .env, MCP config, or CI secrets. Do not commit it or expose it in client side code.
Where to set it
Surface | Location |
|---|---|
| Blockchain MCP | env in MCP client JSON |
| Backend app | .env or secret manager |
| CI | GitHub Actions, GitLab, Vercel, Cloudflare env |
Verify
curl -s -H "x-api-key: $TATUM_API_KEY" \
"https://api.tatum.io/v4/data/exchange-rate?currency=ETH&basePair=USD"A JSON body means the key works. 401 means the header is missing or wrong.