# OATP tx_simulator

> OATP tx_simulator is a paid API for AI agents from api.oatp.cc, paid per call via x402, $0.2/call, status down (last checked 2026-09-15).

Simulates a base64-encoded Solana transaction without broadcasting it, returning success/failure, logs, compute units consumed, and affected accounts.

## Facts

- Endpoint: POST https://api.oatp.cc/tools/tx_simulator
- Price: $0.2/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-oatp-cc-b75edca3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KZwONReduhlqzjWDRYjXS

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 api-oatp-cc-b75edca3 -d '<json body>'
```

Example prompt: Can you simulate this Solana transaction for me without broadcasting it — I want to see if it'll succeed, what logs it produces, and how many compute units it'll use: [base64-encoded transaction string here]?

## When to prefer this

Use this endpoint when you need to dry-run a Solana transaction before broadcasting — especially useful for verifying correctness, estimating compute units, debugging program errors, or confirming that a swap or DeFi operation won't revert. Prefer over live submission whenever safety or cost estimation is a concern.

## Known failure modes

- Invalid or malformed base64 transaction payload returns a deserialization error
- Transaction simulation fails due to insufficient compute budget
- Account not found errors if referenced accounts don't exist on-chain
- Simulation error if the transaction would fail on-chain (e.g. slippage, balance issues)
- HTTP 402 if payment is not included or USDC balance is insufficient

## How this service works

OATP · tx_simulator — Simulate a base64-encoded Solana transaction without broadcasting it. Returns success/err, logs, compute units consumed, and any accounts the simulator surfaces.

## Output

Returns a simulation result including success or error status, program logs from the simulated execution, total compute units consumed, and any accounts the simulator surfaces during the dry run — all without submitting the transaction to the Solana network.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mint": {
   "type": "string",
   "description": "Solana token mint address (base58, 32-44 chars)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-oatp-cc-b75edca3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.oatp.cc](https://www.zero.xyz/host/api.oatp.cc/llms.txt)