windmill-labs/windmill · error

Invalid S3 mode format: {}

Error message

Invalid S3 mode format: {}

What it means

windmill-parser-sql parses S3 mode options passed to SQL scripts (e.g. `s3://...?prefix=x&storage=y&format=csv` style key-value pairs). parse_s3_mode accepts only format values json, parquet, or csv; any other format value makes the parser fail fast with this message so the invalid S3 config never reaches job execution.

Source

Thrown at backend/parsers/windmill-parser-sql/src/lib.rs:188

    let mut prefix = None;
    let mut storage = None;
    let mut format = S3ModeFormat::Json;

    for kv in args_str.split(' ').map(|kv| kv.trim()) {
        if kv.is_empty() {
            continue;
        }
        let mut it = kv.split('=');
        let (Some(key), Some(value)) = (it.next(), it.next()) else {
            return Err(anyhow!("Invalid S3 mode argument: {}", kv));
        };
        match (key.trim(), value.trim()) {
            ("prefix", _) => prefix = Some(value.to_string()),
            ("storage", _) => storage = Some(value.to_string()),
            ("format", "json") => format = S3ModeFormat::Json,
            ("format", "parquet") => format = S3ModeFormat::Parquet,
            ("format", "csv") => format = S3ModeFormat::Csv,
            ("format", format) => return Err(anyhow!("Invalid S3 mode format: {}", format)),
            (_, _) => return Err(anyhow!("Invalid S3 mode argument: {}", kv)),
        }
    }

    Ok(Some(S3ModeArgs { prefix, storage, format }))
}

pub fn parse_sql_blocks(code: &str, track_dollar_quotes: bool) -> Vec<&str> {
    let mut blocks = vec![];
    let mut last_idx = 0;

    run_on_sql_statement_matches(
        code,
        track_dollar_quotes,
        |char, _| char == ';',
        |idx, _| {
            blocks.push(&code[last_idx..=idx]);
            last_idx = idx + 1;

View on GitHub (pinned to e474e8803c)

Solutions

1. Change the format value to one of json, parquet, or csv
2. Check for case mismatches — the match is lowercase-exact
3. If you need another format, it is unsupported by the parser; use one of the three supported ones

Example fix

// before
s3mode=prefix=/data,storage=s3,format=avro
// after
s3mode=prefix=/data,storage=s3,format=parquet

const SUPPORTED = new Set(['json', 'parquet', 'csv']);
function validateS3ModeFormat(format) {
  if (!SUPPORTED.has(format)) throw new Error(`Invalid S3 mode format: ${format}. Use json, parquet, or csv.`);
}
validateS3ModeFormat('parquet'); // call before deploy/parse

function isS3ModeFormat(v) { return v === 'json' || v === 'parquet' || v === 'csv'; }

try {
  parseSqlWithS3Mode(script);
} catch (e) {
  if (String(e).includes('Invalid S3 mode format')) {
    // surface a config-validation message to the user
  } else throw e;
}

When it happens

Trigger: Calling any SQL parse entrypoint (do_bigquery, do_mssql, do_mysql, do_oracledb, do_postgresql, do_snowflake) with an S3 mode argument whose `format` key has a value outside {json, parquet, csv}, e.g. `format=avro` or `format=JSON` (case-sensitive).

Common situations: Typos in format names, uppercase/lowercase mismatch, copying configs from other tools that support more formats (avro, orc), or hand-editing a script's S3 settings in the UI YAML.

Related errors

• Invalid AI agent provider configuration: ${errors.join('\n')
• API key or resource path is required
• Missing a model to test
• Cannot test API key for Custom AI, only resource path is sup
• deleteS3File: s3 key is required

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/b6f7fb973d5f22d7. Report an issue: GitHub.