> Feedback: If these docs are stale, missing, or confusing, post sanitized feedback to `https://docs.tempo.xyz/api/feedback` with `source: "mcp"`, a short `message`, and any relevant `toolName`, `relatedResource`, or `client`.
# T5 Network Upgrade

T5 is Tempo's latest network upgrade. It lowered costs for session-based payments, improved DEX flip-order tracking, simplified fee-token routing, added on-chain token logos, and added witness binding for key authorization flows.

:::info\[T5 status]
T5 is live on testnet and mainnet.
:::

## Timeline

| Network | Date | Timestamp |
|---------|------|-----------|
| Testnet | June 3, 2026 4pm CEST | 1780495200 |
| Mainnet | June 9, 2026 4pm CEST | 1781013600 |

Mainnet node operators needed to upgrade to the T5-compatible release (v1.8.0) before the mainnet activation timestamp.

## Overview

T5 focuses on four integration areas, plus a storage correctness fix:

* **Cheaper payment sessions.** The `TIP20ChannelReserve` precompile gives MPP and other session-based payment apps a protocol-native reserve path.
* **Clearer DEX state.** Flip orders can use the same tick on both sides and keep the same `orderId` after each flip.
* **Simpler fee-token liquidity.** FeeAMM routing can use two hops, so issuers usually do not need a direct pool against every validator payout token.
* **Better token and key metadata.** TIP-20 tokens can expose an on-chain `logoURI`, listed precompiles can pull TIP-20 tokens without a separate approval, and key authorizations can include an app-defined witness digest.
* **Storage correctness fix.** Shrinking writes to dynamic precompile storage clear their stale tail slots at the hardfork boundary ([TIP-1057](https://tips.sh/1057)).

Most T5 changes are additive: existing TIP-20 tokens, MPP contracts, and non-flip DEX flows continue to work.

## Features

### Enshrined TIP-20 reserve channel

The reserve precompile lives at [`0x4D50500000000000000000000000000000000000`](https://explore.tempo.xyz/address/0x4D50500000000000000000000000000000000000) (ASCII `MPP`). It replaces the application-level MPP reserve contract for new integrations, while the existing contract continues to work.

Measured gas savings versus the legacy reserve contract:

| Operation | Legacy contract | Enshrined reserve precompile | Gas reduction |
|---|---:|---:|---:|
| Open channel, existing reserve balance | 1,055,229 | 294,425 | 72% |
| Open channel, first reserve balance | 1,302,429 | 791,625 | 39% |
| Close existing channel | 85,118 | 62,913 | 26% |
| Top up existing channel | 53,724 | 46,805 | 13% |
| Top up and cancel close request | 58,785 | 48,680 | 17% |

These numbers cover only the channel operation itself. Under the legacy path, first-time users also had to send a separate `approve` transaction before opening a channel. With the precompile on the Implicit Approvals List, that approval round trip and allowance storage write are removed.

Read the technical specification at [TIP-1034](https://tips.sh/1034).

### Payment lane classification

T5 moved payment-lane eligibility from local builder policy into consensus. The allow-list covers TIP-20 calls and the new `TIP20ChannelReserve` precompile, so reserve-channel transactions are classified consistently across the network.

Read the technical specification at [TIP-1045](https://tips.sh/1045).

### DEX flip-order improvements

The upgrade changed flip orders in two ways:

* `flipTick == tick` is valid.
* A filled flip order keeps the same `orderId` and emits `OrderFlipped` instead of creating a new order with `OrderPlaced`.

This makes a market-making strategy easier to track over time. Indexers should treat `OrderFlipped` as the latest active state for that `orderId`.

Read the technical specifications at [TIP-1030](https://tips.sh/1030) and [TIP-1056](https://tips.sh/1056).

### Multihop FeeAMM routing

FeeAMM can now route through two pools when there is no usable direct pool between the user's fee token and the validator's payout token.

For token issuers, this usually means pairing against one liquid quote token, such as `pathUSD`, instead of provisioning direct pools against every validator payout token.

Read the technical specification at [TIP-1033](https://tips.sh/1033).

### Optional on-chain logoURI

TIP-20 tokens can expose an optional `logoURI` field. Wallets and explorers can read the official token icon directly from the token contract instead of relying only on the tokenlist registry.

The field is capped at 256 bytes, and non-empty values must use an allowed URI scheme: `https`, `http`, `ipfs`, or `data`.

Read the technical specification at [TIP-1026](https://tips.sh/1026).

### Implicit approvals

Listed protocol precompiles can pull TIP-20 tokens without a prior `approve`. This removes an extra wallet prompt and avoids the allowance storage write for native flows such as DEX orders, DEX swaps, FeeAMM fee collection, and reserve-channel operations.

The internal transfer path is not part of the public TIP-20 ABI and cannot be called by EOAs or external contracts. It still enforces balance checks, TIP-403 transfer policies, AccountKeychain spending limits, and emits the standard TIP-20 `Transfer` event.

Read the technical specification at [TIP-1035](https://tips.sh/1035).

### Witness digest in key authorizations

`key_authorization` now supports an optional `witness: bytes32` field. Apps can bind one key-authorization signature to an application challenge, which removes the need for a separate challenge signature in login or delegated-access flows.

Read the technical specification at [TIP-1053](https://tips.sh/1053).

### Storage correctness fix

T5 gates one precompile storage fix at the hardfork boundary. Overwriting a `Vec`, `String`, or `Bytes` value with a shorter one used to leave the trailing slots populated, so reads past the new length returned stale data. T5 clears those slots on shrinking writes.

This changes storage state and gas at the activation boundary, but no public ABI changes and no integrator action is required.

Read the technical specification at [TIP-1057](https://tips.sh/1057).

## Compatible SDK releases

The following releases support the full T5 feature set. New integrations should prefer the `TIP20ChannelReserve` precompile over the legacy MPP reserve contract.

| Ecosystem  | T5-compatible releases |
| ---------- | ---------------------- |
| TypeScript | [`mppx@0.7.0`](https://github.com/wevm/mppx/releases/tag/mppx%400.7.0), [`viem@2.52.2`](https://github.com/wevm/viem/releases/tag/viem%402.52.2) |
| Rust       | [`tempo-alloy@1.8.0`](https://github.com/tempoxyz/tempo/releases/tag/tempo-alloy%401.8.0), [`tempo-primitives@1.8.0`](https://github.com/tempoxyz/tempo/releases/tag/tempo-primitives%401.8.0), [`tempo-contracts@1.8.0`](https://github.com/tempoxyz/tempo/releases/tag/tempo-contracts%401.8.0) |
| Foundry    | [nightly](https://getfoundry.sh) (T5 hardfork-aware decoding) |

## What operators and integrators should know

T5 is mostly additive. Integrators, indexers, wallets, explorers, and partner infrastructure should review the notes below.

### For MPP and payment-session integrators

* Keep supporting the legacy reserve contract during the transition.
* Prefer the `TIP20ChannelReserve` precompile for new SDK releases.
* Update monitoring to recognize both reserve surfaces.
* Show channel-open, top-up, and close flows from the precompile path.

### For DEX indexers and frontends

* Index `OrderFlipped`.
* Treat `OrderFlipped` as the active state for the same `orderId`.
* Do not assume a filled flip order receives a new `orderId`.
* Remove checks that reject `flipTick == tick`.
* See the [flip-order indexing notes](/docs/protocol/exchange/providing-liquidity#flip-order-indexing).

### For FeeAMM integrators

* Account for two-pool routes when quoting or explaining fee conversion.
* Show route availability from direct pools and multihop paths.
* Make clear that one conversion may reserve and consume liquidity from two pools.

### For token issuers, wallets, and explorers

* Read `logoURI()` directly from TIP-20 contracts when available.
* Continue using the tokenlist for richer metadata and fallback icons.
* Watch `LogoURIUpdated(address indexed updater, string newLogoURI)`.
* Use square, single-frame PNG or WebP images for token icons.

### For key-management and auth flows

* Add the optional `witness` field to key-authorization encoding and decoding.
* Include the witness in signing and verification flows.
* Treat the witness as opaque application data.