> ## Documentation Index
> Fetch the complete documentation index at: https://hs-df36fa00.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Watt ServiceNet Node Environment Variable Reference

> Complete reference for all environment variables that configure a Watt ServiceNet node, including storage, security, gateway policy, and P2P networking.

Watt ServiceNet is configured entirely through environment variables. Set them before starting the node to control persistence, security, gateway policy, and P2P networking. No configuration file is required — every option can be expressed as an environment variable passed to the process or injected via Docker, systemd, or your deployment platform.

## Core

| Variable               | Default          | Description                                                                             |
| ---------------------- | ---------------- | --------------------------------------------------------------------------------------- |
| `SERVICENET_HTTP_ADDR` | `127.0.0.1:8042` | Address the HTTP server binds to. Set to `0.0.0.0:8042` to accept external connections. |

## Storage

| Variable                     | Default  | Description                                                                                                                              |
| ---------------------------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| `SERVICENET_DATABASE_URL`    | *(none)* | PostgreSQL connection URL. When set, the node uses PostgreSQL for all registry, receipt, health, trust, auth-context, and audit storage. |
| `SERVICENET_DATABASE_SCHEMA` | `public` | PostgreSQL schema name. Use this to isolate multiple ServiceNet instances on the same database server.                                   |
| `SERVICENET_REGISTRY_FILE`   | *(none)* | Path to a JSON file for file-backed persistence. Created automatically if it does not exist. Ignored when `DATABASE_URL` is set.         |

When neither `SERVICENET_DATABASE_URL` nor `SERVICENET_REGISTRY_FILE` is set, the node uses in-memory storage and all state is lost on restart. See [Storage Backends](/configuration/persistence) for a full comparison.

## Security

| Variable                                           | Default                              | Description                                                                                                                                                        |
| -------------------------------------------------- | ------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `SERVICENET_SECRET_BROKER_KEY`                     | *(required in DB mode)*              | Base64-encoded 32-byte key used to encrypt auth-context secrets at rest. Required whenever `SERVICENET_DATABASE_URL` is set.                                       |
| `SERVICENET_REQUIRE_PROVIDER_OWNERSHIP_CHALLENGES` | `true` in DB mode, `false` otherwise | Set to `1` to require a signed ownership challenge before a provider can register or rotate its key. Automatically enabled in PostgreSQL mode.                     |
| `SERVICENET_PROVIDER_CHALLENGE_TTL_SECS`           | `300`                                | How long (in seconds) an ownership challenge token remains valid before it expires.                                                                                |
| `SERVICENET_REQUIRE_ADMIN_APPROVE`                 | *(disabled)*                         | Set to `1` to disable auto-approval of agent submissions. Submissions that pass all checks will remain in a pending state until an admin explicitly approves them. |

### Generating a Secret Broker Key

Generate a cryptographically random key before your first PostgreSQL-backed deployment:

```bash theme={null}
# Generate a random 32-byte key and base64-encode it
openssl rand -base64 32
# Example output: BwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwc=
```

Pass the output as `SERVICENET_SECRET_BROKER_KEY`:

```bash theme={null}
SERVICENET_DATABASE_URL=postgres://servicenet:password@localhost:5432/watt-servicenet \
SERVICENET_SECRET_BROKER_KEY=$(openssl rand -base64 32) \
cargo run -p watt-servicenet-node
```

<Warning>
  Never use the placeholder key (`BwcHBwcH...`) shown in example configs in a production deployment. Generate a unique key for every deployment and store it in a secrets manager. Rotating this key after auth-context secrets have been written will make those secrets unreadable.
</Warning>

## Gateway Policy

| Variable                            | Default  | Description                                                                                                                                                                 |
| ----------------------------------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `SERVICENET_GATEWAY_MAX_COST_UNITS` | *(none)* | Default cost cap for all agent invocations routed through the gateway. Agent invocations whose declared cost exceeds this value are rejected at the policy preflight stage. |

## P2P Networking

The variables below control the Iroh-backed P2P sync layer. P2P is disabled by default.

| Variable                              | Default                 | Description                                                                                                             |
| ------------------------------------- | ----------------------- | ----------------------------------------------------------------------------------------------------------------------- |
| `SERVICENET_P2P_ENABLED`              | *(disabled)*            | Set to `1`, `true`, or `yes` to enable P2P gossip and backfill.                                                         |
| `SERVICENET_P2P_NETWORK_ID`           | *(required if enabled)* | Network identifier string. Only nodes sharing the same `NETWORK_ID` exchange records with each other.                   |
| `SERVICENET_P2P_LISTEN_ADDRS`         | *(auto)*                | Comma-separated listen addresses for the Iroh QUIC transport, e.g. `0.0.0.0:4101`.                                      |
| `SERVICENET_P2P_BOOTSTRAP_PEERS`      | *(none)*                | Comma-separated bootstrap peer addresses in `<endpoint_id>@<addr>` format.                                              |
| `SERVICENET_P2P_STATE_DIR`            | `.servicenet-p2p-state` | Directory used to persist the node seed file (`node_seed.hex`) so the node's `EndpointId` stays stable across restarts. |
| `SERVICENET_FEDERATION_MODE`          | `open`                  | Set to `trusted` to restrict inbound registry gossip/backfill to explicitly listed peers.                               |
| `SERVICENET_FEDERATION_TRUSTED_PEERS` | *(none)*                | Comma-separated Iroh `EndpointId` values of trusted peers. Only used when `FEDERATION_MODE=trusted`.                    |

For step-by-step P2P configuration, see [P2P Setup](/guides/p2p-setup). For federation trust policy, see [Federation](/guides/federation).