nautechsystems/nautilus_trader · critical · anyhow::Error

Signer private key environment variable '{}' is not set

Error message

Signer private key environment variable '{}' is not set

What it means

During connect (client.rs:2775) the signer key is read from the environment variable named by config.signer_private_key_env. This error means that variable is not set in the process environment. The key is deliberately never stored in configuration, so a missing env var stops connect before any signature is attempted.

Source

Thrown at crates/adapters/blockchain/src/execution/client.rs:2777

        } else {
            log::warn!(
                "No Postgres cache database configured; transactions will be refused (no durable store)"
            );
        }

        // Verify the RPC chain ID against configuration before any signature
        let expected_chain_id = u64::from(self.chain.chain_id);
        let actual_chain_id = self.http_rpc_client.chain_id().await?;
        if actual_chain_id != expected_chain_id {
            anyhow::bail!(
                "Chain ID mismatch at connect: expected {expected_chain_id}, node reported {actual_chain_id}"
            );
        }

        // Load the signer key from the configured environment variable; the key is never
        // logged, serialized, or stored in configuration
        let private_key = std::env::var(&self.config.signer_private_key_env).map_err(|_| {
            anyhow::anyhow!(
                "Signer private key environment variable '{}' is not set",
                self.config.signer_private_key_env
            )
        })?;
        let signer = PrivateKeySigner::from_str(private_key.trim()).map_err(|_| {
            anyhow::anyhow!(
                "Signer private key in '{}' is not a valid hex private key",
                self.config.signer_private_key_env
            )
        })?;

        if signer.address() != self.wallet_address {
            anyhow::bail!(
                "Signer address {} derived from '{}' does not match configured wallet address {}",
                signer.address(),
                self.config.signer_private_key_env,
                self.wallet_address
            );

View on GitHub (pinned to 2114cf6f76)

Solutions

1. Check the exact name in the error message and verify with printenv / env | grep <NAME> in the same context the process runs.
2. Export or inject the variable into the service environment (secret manager, systemd Environment=, compose env_file).
3. Never place the key value in config files; keep the config pointing at the variable name.
4. Add a startup preflight that fails fast with a clear message if the variable is absent.

Example fix

# before
export PRIVATE_KEY=... # but config expects SIGNER_KEY

# after
# signer_private_key_env = "SIGNER_KEY"
export SIGNER_KEY=0x...  # 32-byte hex private key

// startup preflight:
let key = std::env::var(&config.signer_private_key_env)
    .unwrap_or_else(|_| panic!("env var '{}' must be set before start", config.signer_private_key_env));

fn signer_env_is_set(name: &str) -> bool { std::env::var(name).is_ok() }

Fail startup immediately with the variable name; no retry is useful until the environment is fixed.

When it happens

Trigger: Running under systemd/docker/k8s where the variable was not injected into the unit/compose/pod spec; the variable name in signer_private_key_env does not match what was exported (case-sensitive); the var set in an interactive shell but not in the service environment.

Common situations: Deploying to a new environment without replicating secrets; renaming the env var in config without updating the secret store; CI runs lacking the secret.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

Related errors

• Signer private key in '{}' is not a valid hex private key
• {standard_key_var} not found in config or environment
• {standard_secret_var} not found in config or environment
• Failed to create HTTP client: {e}
• Timeout waiting for account {account_id} to be registered af

AI-assisted analysis of nautechsystems/nautilus_trader@2114cf6f76 (2026-08-21). Data as JSON: /api/errors/d4ee9ea9d1f004f1. Report an issue: GitHub.