> ## Documentation Index
> Fetch the complete documentation index at: https://docs.krews.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Installation

> Install and run an Espresso sequencer node on the Decaf testnet using Docker. Includes hardware requirements, environment variables, and optional staking registration/delegation on Ethereum Sepolia.

<Note>
  Decaf is a **testnet**. Operator access may be **limited**; see Espresso’s announcement and contact form for inclusion. Staking on Decaf uses **Ethereum Sepolia** and the **Decaf stake table**.
</Note>

## Requirements

| Node type       |     CPU |  RAM |     Storage | Notes                                |
| --------------- | ------: | ---: | ----------: | ------------------------------------ |
| Non‑DA node     |  1 core | 2 GB |  negligible | Suitable for observation and testing |
| DA / Sequencer  | 4 cores | 8 GB | 1.2 TB SSD+ | Requires PostgreSQL for SQL storage  |
| PostgreSQL (DA) | 2 cores | 4 GB |   \~100 GB+ | Size grows with chain history        |

<Steps>
  <Step title="Prepare the host">
    Ensure **Docker** is installed and your firewall allows the advertised **libp2p UDP port** you will configure.\
    Create directories for persistent data and keys:

    ```bash theme={null}
    mkdir -p /opt/espresso/{store,keys}
    chmod 700 /opt/espresso/keys
    ```
  </Step>

  <Step title="Provide keys">
    You can pass keys either via a single **key file** or via two environment variables.

    * Key file path inside the container: `/mount/sequencer/keys/0.env`
    * Or set:
      * `ESPRESSO_SEQUENCER_PRIVATE_STAKING_KEY="BLS_SIGNING_KEY~..."`
      * `ESPRESSO_SEQUENCER_PRIVATE_STATE_KEY="SCHNORR_SIGNING_KEY~..."`
  </Step>

  <Step title="Set Decaf environment">
    Export environment variables (edit values as needed). The Docker image tag below is the current Decaf release.

    ```bash theme={null}
    export IMAGE_TAG="20251106-patch1" # Decaf image tag
    export L1_HTTP="https://sepolia.infura.io/v3/<API_KEY>"          # Ethereum Sepolia HTTP
    export L1_WS="wss://sepolia.infura.io/v3/<API_KEY>"              # Ethereum Sepolia WS (recommended)
    export API_PORT="8080"                                           # Sequencer API/metrics
    export LIBP2P_BIND="0.0.0.0:18000/udp"                           # Bind address (UDP)
    export LIBP2P_ADVERTISE="<PUBLIC_IP_OR_DNS>:18000/udp"           # Publicly reachable address

    # Decaf bootstrap/config + core services
    export ESPRESSO_SEQUENCER_CONFIG_PEERS="https://cache.decaf.testnet.espresso.network"
    export ESPRESSO_SEQUENCER_ORCHESTRATOR_URL="https://orchestrator-UZAFTUIMZOT.decaf.testnet.espresso.network/"
    export ESPRESSO_SEQUENCER_CDN_ENDPOINT="cdn.decaf.testnet.espresso.network:1737"
    export ESPRESSO_STATE_RELAY_SERVER_URL="https://state-relay.decaf.testnet.espresso.network"
    export ESPRESSO_SEQUENCER_GENESIS_FILE="/genesis/decaf.toml"

    # Paths inside the container
    export ESPRESSO_SEQUENCER_STORAGE_PATH="/mount/sequencer/store/"
    export ESPRESSO_SEQUENCER_KEY_FILE="/mount/sequencer/keys/0.env"

    # Optional: identify your node in Espresso’s node dashboard
    export ESPRESSO_SEQUENCER_IDENTITY_NODE_NAME="espresso-sequencer-01"
    export ESPRESSO_SEQUENCER_IDENTITY_COMPANY_NAME="YourOrg"
    export ESPRESSO_SEQUENCER_IDENTITY_COMPANY_WEBSITE="https://your.org"
    export ESPRESSO_SEQUENCER_IDENTITY_OPERATING_SYSTEM="$(uname -sr)"
    export ESPRESSO_SEQUENCER_IDENTITY_NETWORK_TYPE="Hosted"         # Residential | Hosted | AWS | GCP | Azure
    export ESPRESSO_SEQUENCER_IDENTITY_COUNTRY_CODE="TR"             # ISO-3166 Alpha-2
    ```
  </Step>

  <Step title="Run a Regular (non‑DA) node">
    ```bash theme={null}
    docker run -d --name espresso-sequencer --restart unless-stopped       -p "${API_PORT}:${API_PORT}"       -v /opt/espresso/store:/mount/sequencer/store       -v /opt/espresso/keys:/mount/sequencer/keys:ro       -e ESPRESSO_SEQUENCER_L1_PROVIDER="${L1_HTTP}"       -e ESPRESSO_SEQUENCER_L1_WS_PROVIDER="${L1_WS}"       -e ESPRESSO_SEQUENCER_CONFIG_PEERS       -e ESPRESSO_SEQUENCER_ORCHESTRATOR_URL       -e ESPRESSO_SEQUENCER_CDN_ENDPOINT       -e ESPRESSO_STATE_RELAY_SERVER_URL       -e ESPRESSO_SEQUENCER_GENESIS_FILE       -e ESPRESSO_SEQUENCER_STORAGE_PATH       -e ESPRESSO_SEQUENCER_KEY_FILE       -e ESPRESSO_SEQUENCER_LIBP2P_BIND_ADDRESS="${LIBP2P_BIND}"       -e ESPRESSO_SEQUENCER_LIBP2P_ADVERTISE_ADDRESS="${LIBP2P_ADVERTISE}"       -e ESPRESSO_SEQUENCER_API_PORT="${API_PORT}"       -e ESPRESSO_SEQUENCER_IDENTITY_NODE_NAME       -e ESPRESSO_SEQUENCER_IDENTITY_COMPANY_NAME       -e ESPRESSO_SEQUENCER_IDENTITY_COMPANY_WEBSITE       -e ESPRESSO_SEQUENCER_IDENTITY_OPERATING_SYSTEM       -e ESPRESSO_SEQUENCER_IDENTITY_NETWORK_TYPE       -e ESPRESSO_SEQUENCER_IDENTITY_COUNTRY_CODE       ghcr.io/espressosystems/espresso-sequencer/sequencer:${IMAGE_TAG}         sequencer -- http -- catchup -- status
    ```
  </Step>

  <Step title="Run a DA (sequencer) node with PostgreSQL">
    Requires a reachable PostgreSQL instance and extra storage.

    ```bash theme={null}
    docker run -d --name espresso-sequencer-da --restart unless-stopped       -p "${API_PORT}:${API_PORT}"       -v /opt/espresso/keys:/mount/sequencer/keys:ro       -e ESPRESSO_SEQUENCER_L1_PROVIDER="${L1_HTTP}"       -e ESPRESSO_SEQUENCER_L1_WS_PROVIDER="${L1_WS}"       -e ESPRESSO_SEQUENCER_CONFIG_PEERS       -e ESPRESSO_SEQUENCER_ORCHESTRATOR_URL       -e ESPRESSO_SEQUENCER_CDN_ENDPOINT       -e ESPRESSO_STATE_RELAY_SERVER_URL       -e ESPRESSO_SEQUENCER_GENESIS_FILE       -e ESPRESSO_SEQUENCER_KEY_FILE       -e ESPRESSO_SEQUENCER_API_PORT="${API_PORT}"       # add your Postgres connection env (e.g., DATABASE_URL) as required by your setup       ghcr.io/espressosystems/espresso-sequencer/sequencer:${IMAGE_TAG}         sequencer -- storage-sql -- http -- catchup -- status -- query
    ```
  </Step>

  <Step title="(Optional) Register & delegate on Sepolia">
    Register the node once to enter the staking set; then delegate to activate.

    ```bash theme={null}
    # Register
    docker run -e L1_PROVIDER="${L1_HTTP}"       -e STAKE_TABLE_ADDRESS="0x40304fbe94d5e7d1492dd90c53a2d63e8506a037"       -e MNEMONIC -e ACCOUNT_INDEX       -e CONSENSUS_PRIVATE_KEY -e STATE_PRIVATE_KEY       ghcr.io/espressosystems/espresso-sequencer/staking-cli:main         staking-cli register-validator --commission 0.10

    # Delegate (bootstrap your own validator or from another account)
    docker run -e L1_PROVIDER="${L1_HTTP}"       -e STAKE_TABLE_ADDRESS="0x40304fbe94d5e7d1492dd90c53a2d63e8506a037"       -e MNEMONIC -e ACCOUNT_INDEX       ghcr.io/espressosystems/espresso-sequencer/staking-cli:main         delegate --validator-address $ADDRESS --amount $DELEGATION_AMOUNT
    ```
  </Step>

  <Step title="Health checks & networking tips">
    * Verify logs: `docker logs -f espresso-sequencer`
    * Ensure the **UDP** libp2p port is open from the Internet to your host.
    * The first start needs `ESPRESSO_SEQUENCER_CONFIG_PEERS`. Subsequent restarts should reuse cached config.
    * Apply **TCP optimizations** per Espresso docs (sysctl or Docker flags).
  </Step>
</Steps>

<Note>
  *Supported networks:* **Espresso Decaf testnet**.
</Note>