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Network Mirror Mode keeps a Virtual Environment continuously aligned with its parent network. New mainnet blocks are absorbed into the Virtual Environment as they’re produced, and a UI-visible mempool collects any transactions you submit. Your transactions are prepended to the next synced block in the order they arrive.
Network Mirror Mode is available on the paid plan. To enable it for your account, contact our sales team.
Network sync status panel showing Mainnet head vs Virtual Environment head block numbers, block lag chart, and time-control buttons

Network Sync page for a Mirror-Mode Virtual Environment: block-lag chart, sync status counters, and the Rewind / Sync block / Start auto-sync controls.

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When to use it

Use Network Mirror Mode when you need to evaluate behavior against live network conditions rather than a frozen fork:
  • Test how your contracts behave against today’s oracle prices, pool reserves, or governance state.
  • Stage a transaction and control when it executes relative to the next synced block.
  • Pause the live network at a specific block to inspect state, then continue replaying.
  • Compare your Virtual Environment’s storage and balances against mainnet baselines over time.
If you need a frozen point-in-time fork, use a standard Virtual Environment. If you need real-time state without mempool semantics or block-for-block ticking, use State Sync.

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How sync works

A mainnet tick produces a Virtual Environment tick within roughly 12 seconds. Each tick brings in the next block’s transactions and applies them on top of your Virtual Environment’s current state. Transactions you submit sit in the Virtual Environment’s mempool until the next sync tick, at which point they’re prepended to the synced block in FIFO order. Your transactions execute first; the synced mainnet transactions execute after them, against the resulting state. A “live” indicator shows whether the Virtual Environment is keeping up:
Network sync status showing Mainnet head 25,239,023 and Virtual Environment head 25,237,977 with 1,046 blocks behind mainnet in orange

Sync status header: Mainnet head, Virtual Environment head, and how many blocks behind mainnet the Virtual Environment currently is.

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Time controls

The time-control strip lets you move the Virtual Environment’s clock relative to mainnet. Each control maps directly to an RPC call you can also invoke from your own code: The speed picker (1×, 2×, 4×, realtime) maps to the tick delay between sync calls (12s, 6s, 3s, and no delay respectively).
Network sync page showing Rewind, Sync block, and Start auto-sync 1x buttons in the top-right of the status card

Time-control strip: Rewind, Sync block, and Start auto-sync with speed multiplier (1×, 2×, 4×, realtime).

To check sync progress programmatically, use tenderly_getSyncStatus.

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State drift lens

The State Drift lens shows where your Virtual Environment has diverged from mainnet. Useful for finding the contract or wallet your test actually moved. Three sub-views share one surface: The lens is scoped to the contracts and wallets you’re watching plus any contracts the current session has touched.
State drift view inside Network Sync, showing the State and Balance tabs and the Track variable / Track balance buttons

State Drift tab: State and Balance sub-views with Track variable and Track balance controls.

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Block-context fidelity

Network Mirror Mode commits to one-to-one parity with the parent network on the dimensions that most often affect contract behavior:
  • Block-context alignment: block.timestamp, baseFee, coinbase, and prevrandao reflect mainnet values.
  • Gas-market parity: current mainnet gas pricing applies to transactions you submit.
  • Sub-tick latency: a mainnet tick produces a Virtual Environment tick within roughly 12 seconds.

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Cheatcode behavior

Because Network Mirror Mode is continuously importing real blocks, some Admin RPC cheatcodes behave differently than on a standard Virtual Environment. See the Admin RPC reference for the full cheatcode list.

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Mode comparison

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Known limitations

  • Single-network only. Network Mirror Mode applies per Virtual Environment; combining it with multichain Virtual Environments isn’t currently supported.

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See also