HumeSQL

HumeSQL turns natural language into safe SQL, runs it against your MySQL/MariaDB database, and returns JSON rows. It introspects your schema, prompts Gemini to craft SQL, applies guardrails, executes the query, and responds with the SQL, reasoning, and results.

• Fast start: drop in DB creds + Gemini key, ask questions in English.
• Safe by default: blocks destructive SQL, adds LIMITs, only uses tables in your schema.
• Flexible: Python API + CLI, schema caching, debug output from the LLM.

Documentation: https://nirajang20.github.io/HumeSQL/

Installation

PyPI:

pip install humesql

From source:

pip install -e .

Quickstart (Python)

from humesql import HumeSQL

db = {
    "host": "localhost",
    "user": "root",
    "password": "",
    "database": "classicmodels",
    "port": 3306,
}

h = HumeSQL(db, model="gemini-2.5-flash")
res = h.query("Show me the last 5 users who signed up from Nepal", debug=True)

if res["ok"]:
    print("SQL:", res["sql"])
    print("Reasoning:", res["reasoning"])
    print("Rows:", res["rows"])
else:
    print("Error:", res["error"])
    if res.get("raw_ai_response"):
        print("Raw:", res["raw_ai_response"])

Response structure (keys may be null on errors):

• ok: bool
• sql: generated SQL
• reasoning: short explanation
• limit_applied: bool or null
• rows: list of result dicts (if SELECT)
• time_ms: total time in milliseconds
• raw_ai_response: only when debug=True

Configuration

Environment variable priority for the Gemini key:

1. Explicit api_key argument
2. HUMESQL_AI_KEY (preferred)
3. HUMANSQL_AI_KEY (legacy)
4. GEMINI_API_KEY

Example:

export HUMESQL_AI_KEY="your-gemini-key"

CLI

Run one-off queries from the terminal:

humesql "last 5 customers from Nepal" \
  -H localhost -u root -p "" -d classicmodels --port 3306 \
  --api-key "$HUMESQL_AI_KEY" --model gemini-2.5-flash --debug

Key flags:

• query (positional): natural language input
• -H/--host, -u/--user, -p/--password, -d/--database, --port
• --api-key: override env vars
• --model: Gemini model (default gemini-2.5-flash)
• --no-cache-schema: disable schema caching
• --debug: include raw AI response in output

Exit code 0 on success, 1 on error.

API highlights

HumeSQL(
    db_config: dict,
    model: str = "gemini-2.5-flash",
    api_key: str | None = None,
    cache_schema: bool = True,
)

• .query(user_text: str, debug: bool = False) -> dict
• .refresh_schema_cache()

Safety guardrails

• Blocks SQL containing DROP, TRUNCATE, ALTER, ;, or information_schema
• Adds LIMIT 100 if the model omits it on SELECT
• Rejects non-JSON or malformed model responses

Schema caching

• Enabled by default; disable with cache_schema=False
• Call refresh_schema_cache() after DB schema changes

Prompting tips

• Be explicit about filters: “last 5 orders from customers in Nepal”
• Name entities when possible: table/column hints help
• State aggregations/ranges: “average order value per month in 2023”

Troubleshooting

• API key not valid: check HUMESQL_AI_KEY or pass --api-key; ensure the key has access to your chosen Gemini model.
• Model not found (404): pick a supported model, e.g., --model gemini-2.5-flash.
• DB connection errors: verify host/port/user/password and MySQL reachability.
• Malformed JSON from model: rerun with debug=True to inspect raw_ai_response.
• Schema changes not reflected: call refresh_schema_cache() or disable caching.

Development

• Install deps: pip install -e .
• Example: set env vars + DB creds, then python example.py
• Type check / lint locally as needed

License

MIT — see LICENSE.