Are you an LLM? Read llms.txt for a summary of the docs, or llms-full.txt for the full context.
Skip to content

simulate

Dry-run an unsigned transaction against the latest committed state and return its outcome.

Signature

async fn simulate(&self, tx: UnsignedTx) -> Result<TxOutcome, anyhow::Error>;

From impl QueryClient for HttpClient. UnsignedTx and TxOutcome are re-exported by the SDK.

Example

use {
    anyhow::Result,
    dango_sdk::{HttpClient, SingleSigner},
    grug::{NonEmpty, QueryClient, Signer},
};
 
async fn estimate_gas(
    http: &HttpClient,
    signer: &SingleSigner<impl dango_sdk::Secret>,
    messages: NonEmpty<Vec<grug::Message>>,
) -> Result<u64> {
    let unsigned = signer.unsigned_transaction(messages, "dango-1")?;
    let outcome  = http.simulate(unsigned).await?;
    Ok(outcome.gas_used as u64)
}

Parameters

tx — UnsignedTx. The transaction body (sender, messages, metadata) without a signature.

Returns

TxOutcome — the simulated outcome, including gas_used, gas_limit, the success/failure result, and emitted events.

Notes

  • Simulation runs without consuming nonce or gas on chain. Authentication is skipped.
  • Apply your own gas buffer — the report is actual usage, not a recommended limit.
  • Builds UnsignedTx via Signer::unsigned_transaction to keep the sender and metadata consistent with what sign_transaction will produce.

See also