> For the complete documentation index, see [llms.txt](https://docs.zeroauthority.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zeroauthority.xyz/nova-bot/nova-tools/transaction-simulation-pre-flight-dry-run.md).

# Transaction Simulation (Pre-flight / Dry-run)

Transaction Simulation lets you **dry-run a proposed transaction before you ever sign it**. You describe an action — a transfer, a swap, a contract or program call — and Nova runs it against **live on-chain state** and tells you what *would* happen, **without broadcasting anything and without moving any funds**.

You get back: whether the transaction would **succeed or revert** (and the reason), the **asset changes** (who gains or loses what), the real **fee / gas / compute cost**, and — for tokens — a **honeypot / sellability** verdict.

{% hint style="success" %}
**Read-only and keyless.** Simulation never signs, never broadcasts, and never moves funds. The "from" address does **not** have to be yours — you can simulate from any address. No admin or DM required.
{% endhint %}

{% hint style="warning" %}
A simulation reflects **current chain state at the moment you run it**. It is not a guarantee the real transaction will behave identically later (state, prices, and liquidity move), and it is **not financial advice**.
{% endhint %}

***

## Supported Chains

| Chain                                                                 | What it covers                                                                                                                                                                                                 |
| --------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Stacks**                                                            | STX transfers (fee + balance check), Clarity contract calls (real evaluation of read-only functions; ABI validation + fee + static asset-movement scan for state-changing functions), SIP-010 sellability scan |
| **EVM** (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, Avalanche) | Native + ERC-20 transfers, arbitrary contract calls (success/revert + gas), ERC-20 honeypot/sellability                                                                                                        |
| **Solana**                                                            | Native SOL + SPL transfers, arbitrary program instructions, fully-serialized transactions (e.g. a Jupiter swap), SPL sellability                                                                               |

***

## What You Can Simulate

| Action                      | What you provide                                           | What you get                                                        |
| --------------------------- | ---------------------------------------------------------- | ------------------------------------------------------------------- |
| **Transfer**                | `from`, `to`, `amount` (+ token/mint for a token transfer) | success/revert, asset changes, fee/gas/compute                      |
| **Contract / program call** | the contract (or program) + function/calldata + args       | success or revert (+ reason), cost, asset movements where derivable |
| **Sellability / honeypot**  | `token` (+ a `holder` that owns it)                        | a verdict: **sellable**, **likely honeypot**, or **inconclusive**   |

***

## Honeypot / Sellability Check

The headline check. A *honeypot* token lets you **buy** but blocks you from **selling**. Transaction Simulation tests the sell side directly:

* **EVM** — `eth_call`-executes a transfer of the holder's full balance against live state. If the transfer **reverts** or **returns false** (blacklist, pause, trading-disabled), the token is flagged as a likely honeypot.
* **Solana** — simulates moving the SPL token out of the holder. A **frozen / non-transferable** token fails here.
* **Stacks** — statically scans the SIP-010 `transfer` source for **pause flags, blacklist maps, and owner-only guards** that could block sells. For a full Clarity audit, pair it with the **Token Risk Check**.

The sell test needs a **holder that actually owns the token** (for example, an address that just bought it). If the holder's balance is `0`, the result is **inconclusive** rather than a false "honeypot." On the current RPC tier, fee-on-transfer **tax %** is not measured on EVM.

***

## Example Prompts

> "Simulate sending 0.5 ETH from 0xabc… to 0xdef… on Base — will it go through and what's the gas?"

> "Dry-run calling `claim` on SP….my-contract — would it revert?"

> "Is 0x… on Ethereum a honeypot? Can this wallet actually sell it?"

> "Preview swapping this Jupiter transaction before I sign it." *(pass the serialized transaction)*

> "What would this STX transfer cost and does my wallet cover it?"

***

## Using It From an Agent (x402 / MCP)

The per-chain tools are exposed on the public Tools Platform as `stacks-tx-simulate`, `evm-tx-simulate`, and `solana-tx-simulate` (REST + MCP). Agents can call them to **verify sellability before relying on a token** or to **pre-flight a transaction before broadcasting it themselves**.