Hmbown/CodeWhale · error · anyhow

A managed, project or plugin connector already uses this…

Error message

A managed, project or plugin connector already uses this name

What it means

Before inserting the imported server, apply checks that the name is not already taken by a managed, project, or plugin connector — checked against both the merged view (`context.merged()`) and the file being mutated (`config.servers`). Name collisions would create ambiguous connector references, so approval is refused.

Solutions

  1. Rename the existing server or the imported one in its source config so the names differ.
  2. Remove the existing duplicate connector if the imported one should replace it.
  3. Decline this candidate and import the source under a different name after editing the source config.

Example fix

// before (source config)
{"mcpServers": {"fetch": {...}}}
// after
{"mcpServers": {"fetch-from-claude": {...}}}
Defensive patterns

Strategy: validation

Validate before calling

let name = &candidate.name;
let taken = context.merged()?.servers.contains_key(name)
    || config.servers.contains_key(name);
if taken { eprintln!("name {name} already used; rename before importing"); }

Try / catch

match apply_reviewed_import(...) {
    Err(e) if e.to_string().contains("already uses this name") => {
        // rename in the source config or remove the existing connector, then retry
    }
    other => other?,
}

Prevention

When it happens

Trigger: Approving an import whose candidate server name collides with an existing managed/project/plugin MCP server of the same name in the codewhale config.

Common situations: Two external clients export a server with the same generic name (e.g. "filesystem", "fetch"); the user already added that connector manually; a previous import already claimed the name.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/9d66e6f3673896a9. Report an issue: GitHub.

Appendix: source

Thrown at crates/tui/src/mcp/external_import.rs:688

    );
    let (candidate, revision) = super::mutate_config(context.mcp_path, Some(revision), |config| {
        let (candidates, _) = context.discover();
        let candidate = candidates
            .into_iter()
            .find(|candidate| candidate_id(candidate) == id)
            .ok_or_else(|| {
                anyhow::anyhow!("Reviewed source is unavailable; refresh the import preview")
            })?;
        anyhow::ensure!(
            candidate.content_hash == hash,
            "Source changed; refresh the import preview"
        );
        if decision == ImportDecision::Approve {
            anyhow::ensure!(
                !source_blocked(context, &candidate),
                "Source is disabled or its workspace is untrusted"
            );
            anyhow::ensure!(
                !context.merged()?.servers.contains_key(&candidate.name)
                    && !config.servers.contains_key(&candidate.name),
                "A managed, project or plugin connector already uses this name"
            );
            let mut server = candidate.server.clone();
            server.enabled = false;
            server.disabled = true;
            config.servers.insert(candidate.name.clone(), server);
        }
        Ok(candidate)
    })?;
    let decisions = HashMap::from([(candidate.name.clone(), decision)]);
    let now = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .map_or(0, |time| time.as_secs());
    let consent_recorded = persist_decisions(
        &context.codewhale_home.join("mcp-import-consent.json"),
        std::slice::from_ref(&candidate),

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