zeroclaw-labs/zeroclaw · error

IPv6 hosts are not supported in web_fetch

Error message

IPv6 hosts are not supported in web_fetch

What it means

Error "IPv6 hosts are not supported in web_fetch" thrown in zeroclaw-labs/zeroclaw.

Source

Thrown at crates/zeroclaw-tools/src/web_fetch.rs:820

            ::zeroclaw_log::Event::new(module_path!(), ::zeroclaw_log::Action::Reject)
                .with_outcome(::zeroclaw_log::EventOutcome::Failure)
                .with_attrs(::serde_json::json!({"url": url})),
            "web_fetch: non-http(s) URL rejected"
        );
        anyhow::bail!("Only http:// and https:// URLs are allowed");
    }

    if !parsed.username().is_empty() || parsed.password().is_some() {
        anyhow::bail!("URL userinfo is not allowed");
    }

    let host = parsed
        .host_str()
        .ok_or_else(|| anyhow::Error::msg("URL must include a host"))?;
    // `Url::host_str()` serializes IPv6 literals with brackets, so parsing the
    // returned string directly would never recognize them.
    if host.starts_with('[') {
        anyhow::bail!("IPv6 hosts are not supported in web_fetch");
    }

    let host = host.trim_end_matches('.').to_ascii_lowercase();

    if host.is_empty() {
        anyhow::bail!("URL must include a valid host");
    }

    Ok(host)
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum PrivateAllow {
    /// Not covered by the private allowlist.
    None,
    /// Covered only by a `*` wildcard entry.
    Wildcard,
    /// Covered by a specific host/IP or suffix entry.

View on GitHub (pinned to 88bb9c8533)

Solutions

1. Use an IPv4 address or a DNS hostname that resolves to IPv4 instead of a literal IPv6 address.
2. Add a DNS name for the IPv6 host and fetch via that hostname.

When it happens

Trigger: Thrown at crates/zeroclaw-tools/src/web_fetch.rs:820 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zeroclaw-labs/zeroclaw@88bb9c8533 (2026-08-23). Data as JSON: /api/errors/8483d0d9b7454868. Report an issue: GitHub.