diff --git a/hotshot-state-prover/README.md b/hotshot-state-prover/README.md
index 3bbb7d0616..7e90e834ac 100644
--- a/hotshot-state-prover/README.md
+++ b/hotshot-state-prover/README.md
@@ -9,11 +9,12 @@
 The HotShot light client is an on-chain contract that tracks the latest state of the HotShot consensus protocol. The
 light client maintains the following fields:
 
-| Field             | Details                                  |
-| ----------------- | ---------------------------------------- |
-| `view_number`     | The latest view number of the consensus  |
-| `block_height`    | The latest block height of the consensus |
-| `block_comm_root` | Root commitment of the block Merkle tree |
+| Field             | Version added | Details                                                |
+| ----------------- | ------------- | ------------------------------------------------------ |
+| `view_number`     | V1            | Latest view number of the consensus.                   |
+| `block_height`    | V1            | Latest block height of the consensus.                  |
+| `block_comm_root` | V1            | Root commitment of the block Merkle tree.              |
+| `auth_root`       | V3            | Keccak-256 hash of auxiliary information to be signed. |
 
 The block Merkle tree accumulates all historical blocks up to `block_height`. Its root commitment serves as an
 authenticated checkpoint for applications relying on HotShot consensus.
@@ -29,6 +30,12 @@ table consists of:
 3. A hash of all stake weights
 4. The threshold for the total weight required to update the contract state
 
+### Auth Root
+
+Starting from light client V3, the contract also tracks a new field `auth_root`, which is the Keccak-256 hash of some
+auxiliary information to be authenticated by the validator, so that the other applications on chain can easily verify.
+Currently, it includes the root commitment of the reward Merkle tree.
+
 ### HotShot State Prover
 
 The HotShot state prover is responsible for generating _state update proofs_ that the light client contract can verify.
@@ -69,3 +76,8 @@ maintaining consensus integrity across epochs.
 
 The prover can also run in a legacy mode for older contract versions. The application automatically detects the contract
 version and runs the appropriate service. The legacy service implementation can be found in `src/legacy/service.rs`.
+
+## Important Notes
+
+Recently we fixed a critical bug in the circuit, details can be found [here](https://github.com/espressosystems/espresso-network/pull/126).
+The circuit change is breaking, resulting in the incompatibility between the old and the new prover/contract.
diff --git a/hotshot-state-prover/RUNBOOK.md b/hotshot-state-prover/RUNBOOK.md
index bb4a5d6b42..80bcab0daf 100644
--- a/hotshot-state-prover/RUNBOOK.md
+++ b/hotshot-state-prover/RUNBOOK.md
@@ -109,7 +109,7 @@ version and runs the appropriate service. The legacy service implementation can
   `stake_table_capacity` are configured correctly across the sequencers, relay server, and the prover.
 - **Contract Error:** Check logs for `ProverError::ContractError`. Ensure the provider urls are valid and the contract
   address is correct. If there's an error code, search it in the
-  [bindings](../contracts/rust/adapter/src/bindings/lightclientv2.rs) for further debugging information.
+  [bindings](../contracts/rust/adapter/src/bindings/lightclientv3.rs) for further debugging information.
 - **Gas Price Too High:** Check logs for `ProverError::GasPriceTooHigh`. Adjust the `max_gas_price` in the configuration
   or wait for the gas price to drop.
 - **Proof Generation Failure, Epoch Already Started:** These usually indicate a configuration issue.