What causes "Codestral API error: {} - {}" in zed-industries/zed?

Read the status/body in the message: 401 → fix the API key, 429 → slow down or raise quota, 404 → fix the model name

zed-industries/zed · error · anyhow::Error

Codestral API error: {} - {}

Error message

Codestral API error: {} - {}

What it means

A completion request to the Codestral API returned a non-success HTTP status; the status code and full response body are embedded in the error. The body normally contains the API's own explanation (invalid key, unknown model, rate limit).

Source

Thrown at crates/codestral/src/codestral.rs:165

        log::debug!("Codestral: Sending FIM request");

        let http_request = http_client::Request::builder()
            .method(http_client::Method::POST)
            .uri(format!("{}/v1/fim/completions", api_url))
            .header("Content-Type", "application/json")
            .header("Authorization", format!("Bearer {}", api_key))
            .body(http_client::AsyncBody::from(request_body))?;

        let mut response = http_client.send(http_request).await?;
        let status = response.status();

        log::debug!("Codestral: Response status: {}", status);

        if !status.is_success() {
            let mut body = String::new();
            response.body_mut().read_to_string(&mut body).await?;
            return Err(anyhow::anyhow!(
                "Codestral API error: {} - {}",
                status,
                body
            ));
        }

        let mut body = String::new();
        response.body_mut().read_to_string(&mut body).await?;

        let codestral_response: CodestralResponse = serde_json::from_str(&body)?;

        let elapsed = start_time.elapsed();

        if let Some(choice) = codestral_response.choices.first() {
            let completion = &choice.message.content;

            log::debug!(
                "Codestral: Completion received ({} tokens, {:.2}s)",

View on GitHub (pinned to bc538def45)

Solutions

Read the status/body in the message: 401 → fix the API key, 429 → slow down or raise quota, 404 → fix the model name
Verify the key with a minimal curl request to the Codestral API
Add backoff/retry only for 429 and 5xx, never for 4xx auth errors

Example fix

// before: surfacing raw error
let response = http_client.send(http_request).await?;

// after: classify status before failing
let status = response.status();
if status == StatusCode::UNAUTHORIZED {
    anyhow::bail!("Codestral API key rejected; update your credentials");
}
if !status.is_success() {
    anyhow::bail!("Codestral API error: {} - {}", status, body);
}

Defensive patterns

Strategy: try-catch

Validate before calling

// validate request inputs before sending
if api_key.is_empty() {
    anyhow::bail!("Codestral API key is empty");
}
if !KNOWN_MODELS.contains(&model.as_str()) {
    anyhow::bail!("unknown Codestral model: {model}");
}

Try / catch

let status = response.status();
if status == StatusCode::UNAUTHORIZED {
    anyhow::bail!("Codestral rejected the API key; update credentials");
}
if status == StatusCode::TOO_MANY_REQUESTS {
    // retryable: honor Retry-After if present
    let wait = response
        .headers()
        .get("Retry-After")
        .and_then(|v| v.to_str().ok())
        .and_then(|v| v.parse::<u64>().ok())
        .unwrap_or(5);
    executor.timer(Duration::from_secs(wait)).await;
    return self.complete(request_body).await;
}
if !status.is_success() {
    anyhow::bail!("Codestral API error: {} - {}", status, body);
}

Prevention

Never retry 401/403 — fix the key instead
Rate-limit inline completion requests locally to avoid 429s
Log status plus body once per failure; the body names the real cause

When it happens

Trigger: POST to the Codestral completion endpoint returns 401 (bad API key), 429 (rate limit/quota), 400/404 (invalid model name or malformed request body), or 5xx.

Common situations: Expired or mistyped API key in Zed's Codestral settings; using a model name the key's plan does not allow; bursts of inline-completion requests exceeding quotas.

Related errors

AI-assisted analysis of zed-industries/zed@bc538def45 (2026-08-16). Data as JSON: /api/errors/759c061f936342bb. Report an issue: GitHub.