# Mesa Fork Schedule > Concrete fork-schedule values for the Mesa upgrade — Mesa genesis timestamp, stop-transaction-slot (slot_tx_end), stop-network-slot (slot_chain_end), and pre-fork / Mesa release versions per network. Canonical URL: https://docs.minaprotocol.com/network-upgrades/mesa/fork-schedule This page collects the concrete fork-schedule values for the Mesa upgrade per network. If you are integrating with Mina (exchange, custodian, indexer, Rosetta consumer, monitoring), this is the single source of truth for **when** to act and **which release** to run. The relevant moments are: - **`stop-transaction-slot`** (a.k.a. `slot_tx_end` in the daemon config) — the slot at which nodes stop accepting new user transactions. Block production continues with empty blocks until the network-slot. See the [glossary entry](/network-upgrades/mesa/glossary#stop-transaction-slot). - **`stop-network-slot`** (a.k.a. `slot_chain_end`) — the slot at which block production halts entirely. The network is offline between this slot and the Mesa genesis timestamp. See the [glossary entry](/network-upgrades/mesa/glossary#stop-network-slot). - **Mesa genesis timestamp** — the wall-clock time at which the first block on the Mesa chain is produced. Exactly 3 hours after the _stop-network-slot_. See the [glossary entry](/network-upgrades/mesa/glossary#mesa-genesis-timestamp). ## Mainnet :::info Upgrade day is 2026-09-03 The mainnet stop-slot schedule is published and is compiled into the releases below. Announced in the [3.5.0 Mainnet Stop Slot Release](https://github.com/MinaProtocol/mina/releases/tag/3.5.0-mainnet-stop-slot) and the [4.0.0 Mainnet Automode Upgrade Release](https://github.com/MinaProtocol/mina/releases/tag/4.0.0-mainnet). ::: | Field | Value | | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | | Pre-fork (stop-slot) release | [`3.5.0-mainnet-stop-slot`](https://github.com/MinaProtocol/mina/releases/tag/3.5.0-mainnet-stop-slot) — `mina-mainnet=3.5.0-mainnet-stop-slot-5e100ee` | | Automode release | [`4.0.0-mainnet`](https://github.com/MinaProtocol/mina/releases/tag/4.0.0-mainnet) — `mina-mainnet-automode=4.0.0-mainnet-893c877` | | Mesa release (manual mode only) | [`4.0.0-mainnet-mesa`](https://github.com/MinaProtocol/mina/releases/tag/4.0.0-mainnet-mesa) — `mina-mainnet=4.0.0-6850301` | | `stop-transaction-slot` (`slot_tx_end`) | Slot **393800** — 2026-09-03 10:00 UTC | | `stop-network-slot` (`slot_chain_end`) | Slot **393900** — 2026-09-03 15:00 UTC | | Mesa genesis timestamp (UTC) | 2026-09-03 18:00 (`hard_fork_genesis_slot_delta` = 60 slots = 3 hours) | | State Finalization window | Exactly 100 slots = exactly 5 hours between `slot_tx_end` and `slot_chain_end` | Both mainnet packages come from the `stable` channel on `packages.o1test.net`. Run **one** of the two releases: - **Automode** — install `mina-mainnet-automode=4.0.0-mainnet-893c877` before the stop-transaction-slot. The dispatcher swaps to the Mesa binary by itself. No second upgrade. - **Manual** — install `mina-mainnet=3.5.0-mainnet-stop-slot-5e100ee` before the stop-transaction-slot, keep it running until the stop-network-slot, then install the Mesa release when it is published. See [Upgrade Modes](/network-upgrades/mesa/upgrade-modes). The archive package for both paths is `mina-archive=3.5.0-mainnet-stop-slot-5e100ee`. ## Devnet :::note Devnet forked on 2026-08-19 Devnet is on Mesa. The values below are historical; they will not change. ::: | Field | Value | | --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- | | Pre-fork (stop-slot) release | [`3.5.0-devnet-stop-slot`](https://github.com/MinaProtocol/mina/releases/tag/3.5.0-devnet-stop-slot) — `mina-devnet=3.5.0-devnet-stop-slot-849edfa` | | Automode release | [`4.0.0-devnet`](https://github.com/MinaProtocol/mina/releases/tag/4.0.0-devnet) — `mina-devnet-automode=4.0.0-devnet-2dc9218` | | Mesa release (manual mode only) | [`4.0.0-devnet-mesa`](https://github.com/MinaProtocol/mina/releases/tag/4.0.0-devnet-mesa) — `mina-devnet=4.0.0-6965b50` | | `stop-transaction-slot` (`slot_tx_end`) | Slot **413540** — 2026-08-19 10:00 UTC | | `stop-network-slot` (`slot_chain_end`) | Slot **413640** — 2026-08-19 15:00 UTC | | Mesa genesis timestamp (UTC) | 2026-08-19 18:00 | | State Finalization window | Exactly 100 slots = exactly 5 hours between `slot_tx_end` and `slot_chain_end` | Devnet packages come from the `alpha` channel on `packages.o1test.net`. A node that joins devnet now must use `mina-devnet=4.0.0-6965b50`; the two pre-fork releases can no longer connect. ## Preflight (archived) The Mesa preflight network is archived — it is no longer running and its builds are no longer supported. The numbers below are historical; they will not change. | Field | Value | | --------------------------------------- | ------------------------------ | | Pre-fork release | `4.0.0-preflight1-b649c79` | | Stop-slot release | `4.0.0-preflight-stop-2967b39` | | Mesa release | `4.0.0-preflight-3f038cb` | | Mesa hard-fork time (UTC) | 2026-04-27 13:00 | | Transaction protocol version after fork | 5.0.0 | | o1js version targeting protocol v5.0.0 | `o1js@3.0.0-mesa.698ca` | The **MUT** network (`mesa-mut`), which ran the same sequence on `4.0.0-rc1` builds, is also archived. For the full context on both archived networks, see [Archived Networks](/network-upgrades/mesa/archived-networks). ## How to use these values - **Exchanges**: schedule your deposit/withdrawal freeze to begin **before** `stop-transaction-slot` and re-enable **after** the Mesa genesis timestamp confirms block production. See the [Exchanges tab on Post-Upgrade](/network-upgrades/mesa/upgrade-steps/post-upgrade) for the full checklist. - **Block producers**: install the stop-slot release any time before `stop-transaction-slot`. If you are using [automode](/network-upgrades/mesa/upgrade-modes), no further action is needed — the dispatcher will swap to the Mesa binary automatically after the Mesa release is published. - **Archive operators**: schedule the archive schema upgrade for any time on or after `stop-network-slot`. The script is backward compatible and can also be run earlier. See [Archive Upgrade](/network-upgrades/mesa/archive-upgrade). - **Rosetta operators**: follow the manual-mode timeline — Rosetta does not support automode. See [Upgrade Modes](/network-upgrades/mesa/upgrade-modes).