# TzKT Tezos Account Balance API

> TzKT Tezos Account Balance API is a paid API for AI agents from x402.tzkt.io, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Returns the current XTZ balance of a specific Tezos account address

## Facts

- Endpoint: POST https://x402.tzkt.io/v1/accounts/%7Baddress%7D/balance
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tzkt-tezos-account-balance-api-c18e38ff
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_l7dkFuH87SYy7HOolG1nJ

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability tzkt-tezos-account-balance-api-c18e38ff -d '<json body>'
```

Example prompt: What's the current XTZ balance of the Tezos address tz1VSUr8wwNhLAzempoch5d6hLRiTh8Cjcjb on TzKT?

## When to prefer this

Use this endpoint when you need a fast, no-auth balance lookup for any Tezos address (tz1, tz2, tz3, or KT1 contract addresses). TzKT is the most comprehensive and widely trusted Tezos indexer, making it ideal for production agents that need reliable on-chain data. Prefer this over direct RPC node calls when you want indexed, human-readable responses without managing your own node infrastructure. The x402 micropayment model at $0.002/call makes it cost-effective for high-frequency balance checks.

## Known failure modes

- Invalid or malformed Tezos address format returns an error
- Address that has never been activated on-chain may return 0 or not found
- Network congestion may cause slightly stale data
- Non-existent address returns 0 balance rather than an error
- Rate limiting if too many requests are made rapidly

## How this service works

TzKT is a comprehensive Tezos blockchain indexer API. Access blocks, operations, accounts, contracts, bigmaps, delegates, tokens and network stats through a fast REST API. No signup or API key required.

## Output

Returns the account's current balance in mutez (1 XTZ = 1,000,000 mutez) as a numeric value. The agent can convert this to XTZ for display. The response reflects the on-chain confirmed balance at the time of the query.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tzkt-tezos-account-balance-api-c18e38ff/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.tzkt.io](https://www.zero.xyz/host/x402.tzkt.io/llms.txt)