feat: Add CLI

CHANGELOG.md

@@ -7,6 +7,11 @@
 1. [#198](https://github.com/InfluxCommunity/influxdb3-python/pull/198): Support custom tag order via `tag_order` write option.
    See [Sort tags by priority](https://docs.influxdata.com/influxdb3/enterprise/write-data/best-practices/schema-design/#sort-tags-by-query-priority) for more.
 1. [#202](https://github.com/InfluxCommunity/influxdb3-python/pull/202): Add escape for field keys when serializing to line protocol in `PolarsDataframeSerializer`.
+1. [#208](https://github.com/InfluxCommunity/influxdb3-python/pull/208): Add `influx3 query` CLI support for executing SQL/InfluxQL queries with JSON/JSONL/CSV/pretty output, including module execution via `python -m influxdb_client_3`.
+
+### Bug Fixes
+
+1. [#208](https://github.com/InfluxCommunity/influxdb3-python/pull/208): Normalize PEM certificate line endings when loading Flight query root certificates to ensure consistent SSL option behavior on Windows.
 
 ## 0.18.0 [2026-02-19]
 

README.md

@@ -51,6 +51,44 @@ Note: This does not include Pandas support. If you would like to use key feature
 
 *Note: Please make sure you are using 3.9 or above. For the best performance use 3.11+*
 
+## CLI (Agent-Friendly Query Tool)
+
+This package includes an `influx3` CLI for read/query workflows.
+
+### Run a query
+
+```bash
+influx3 query -d my_database "SELECT * FROM cpu LIMIT 5"
+```
+
+By default, output is JSON to stdout.
+
+### Supported formats
+
+- `json` (default)
+- `jsonl`
+- `csv`
+- `pretty`
+
+```bash
+influx3 query -d my_database --format csv "SELECT * FROM cpu LIMIT 5"
+```
+
+### Config precedence
+
+Configuration values are resolved in this order:
+
+1. CLI flags
+2. `INFLUXDB3_*` environment variables
+3. legacy `INFLUX_*` environment variables
+4. built-in defaults (host defaults to `http://127.0.0.1:8181`)
+
+Relevant environment variables:
+
+- `INFLUXDB3_HOST_URL` (legacy fallback: `INFLUX_HOST`)
+- `INFLUXDB3_DATABASE_NAME` (legacy fallback: `INFLUX_DATABASE`)
+- `INFLUXDB3_AUTH_TOKEN` (legacy fallback: `INFLUX_TOKEN`)
+
 # Usage
 One of the easiest ways to get started is to checkout the ["Pokemon Trainer Cookbook"](https://github.com/InfluxCommunity/influxdb3-python/blob/main/Examples/pokemon-trainer/cookbook.ipynb). This scenario takes you through the basics of both the client library and Pyarrow.
 

influxdb_client_3/__main__.py

@@ -0,0 +1,5 @@
+from influxdb_client_3.cli import main
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

influxdb_client_3/cli.py

@@ -0,0 +1,180 @@
+import argparse
+import csv
+import io
+import json
+import os
+import sys
+from typing import Mapping, Optional
+
+import pyarrow as pa
+
+from influxdb_client_3 import (
+    INFLUX_DATABASE,
+    INFLUX_HOST,
+    INFLUX_TOKEN,
+    InfluxDBClient3,
+)
+from influxdb_client_3.exceptions import InfluxDB3ClientQueryError, InfluxDBError
+
+
+def _resolve_option(
+    cli_value: Optional[str],
+    env: Mapping[str, str],
+    primary_env: str,
+    secondary_env: Optional[str] = None,
+    default: Optional[str] = None,
+) -> Optional[str]:
+    if cli_value is not None:
+        return cli_value
+
+    for var in (primary_env, secondary_env):
+        if not var:
+            continue
+        value = env.get(var)
+        if value not in (None, ""):
+            return value
+
+    return default
+
+
+def _rows_to_csv(rows, fieldnames):
+    buff = io.StringIO()
+    writer = csv.DictWriter(buff, fieldnames=fieldnames)
+    writer.writeheader()
+    for row in rows:
+        writer.writerow(row)
+    return buff.getvalue()
+
+
+def _rows_to_pretty(rows, fieldnames):
+    if not rows:
+        return "(0 rows)"
+
+    widths = {name: len(name) for name in fieldnames}
+    for row in rows:
+        for name in fieldnames:
+            widths[name] = max(widths[name], len(str(row.get(name, ""))))
+
+    header = " | ".join(name.ljust(widths[name]) for name in fieldnames)
+    sep = "-+-".join("-" * widths[name] for name in fieldnames)
+    lines = [header, sep]
+    for row in rows:
+        lines.append(" | ".join(str(row.get(name, "")).ljust(widths[name]) for name in fieldnames))
+    return "\n".join(lines)
+
+
+def _rows_to_json(rows, fieldnames):
+    return json.dumps(rows, default=str)
+
+
+def _rows_to_jsonl(rows, fieldnames):
+    return "\n".join(json.dumps(row, default=str) for row in rows)
+
+
+_FORMATTERS = {
+    "json": _rows_to_json,
+    "jsonl": _rows_to_jsonl,
+    "csv": _rows_to_csv,
+    "pretty": _rows_to_pretty,
+}
+
+
+def _format_table(table: pa.Table, output_format: str) -> str:
+    rows = table.to_pylist()
+    fieldnames = table.schema.names
+    return _FORMATTERS[output_format](rows, fieldnames)
+
+
+def _ensure_trailing_nl(text: str) -> str:
+    return text if text.endswith("\n") else text + "\n"
+
+
+def _write_error(stderr, message: str):
+    stderr.write(json.dumps({"error": str(message)}) + "\n")
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(prog="influx3", description="InfluxDB 3 query CLI")
+    subparsers = parser.add_subparsers(dest="command", required=True)
+
+    query_parser = subparsers.add_parser("query", aliases=["q"], help="Run a SQL or InfluxQL query")
+    query_parser.add_argument("query", nargs="?", help="The query string to execute")
+    query_parser.add_argument("-f", "--file", dest="file_path", help="File containing the query")
+    query_parser.add_argument("-H", "--host", dest="host", help="InfluxDB host URL")
+    query_parser.add_argument("-d", "--database", dest="database", help="Database name")
+    query_parser.add_argument("--token", dest="token", help="Authentication token")
+    query_parser.add_argument(
+        "-l",
+        "--language",
+        dest="language",
+        choices=["sql", "influxql"],
+        default="sql",
+        help="Query language",
+    )
+    query_parser.add_argument(
+        "--format",
+        dest="output_format",
+        choices=list(_FORMATTERS),
+        default="json",
+        help="Output format",
+    )
+    query_parser.add_argument("-o", "--output", dest="output_file_path", help="Write output to file")
+    query_parser.add_argument("--query-timeout", dest="query_timeout", type=int, help="Query timeout in ms")
+    query_parser.set_defaults(func=_run_query)
+    return parser
+
+
+def _run_query(args, stdout, stderr, env: Optional[Mapping[str, str]] = None) -> int:
+    if env is None:
+        env = os.environ
+
+    host = _resolve_option(args.host, env, "INFLUXDB3_HOST_URL", INFLUX_HOST, "http://127.0.0.1:8181")
+    database = _resolve_option(args.database, env, "INFLUXDB3_DATABASE_NAME", INFLUX_DATABASE)
+    token = _resolve_option(args.token, env, "INFLUXDB3_AUTH_TOKEN", INFLUX_TOKEN)
+
+    if (args.query is None) == (args.file_path is None):
+        _write_error(stderr, "Provide exactly one of query or --file.")
+        return 1
+
+    if not database:
+        _write_error(stderr, "Database is required. Set --database or INFLUXDB3_DATABASE_NAME.")
+        return 1
+
+    try:
+        query = args.query
+        if args.file_path:
+            with open(args.file_path, "r", encoding="utf-8") as file_handle:
+                query = file_handle.read()
+
+        query_kwargs = {}
+        if args.query_timeout is not None:
+            query_kwargs["query_timeout"] = args.query_timeout
+
+        with InfluxDBClient3(host=host, database=database, token=token, **query_kwargs) as client:
+            table = client.query(
+                query=query,
+                language=args.language,
+                mode="all",
+                database=database,
+            )
+
+        payload = _ensure_trailing_nl(_format_table(table, args.output_format))
+        if args.output_file_path:
+            with open(args.output_file_path, "w", encoding="utf-8", newline="") as file_handle:
+                file_handle.write(payload)
+        else:
+            stdout.write(payload)
+        return 0
+    except (InfluxDB3ClientQueryError, InfluxDBError, OSError, pa.ArrowException) as error:
+        _write_error(stderr, str(error))
+        return 1
+
+
+def main(argv=None) -> int:
+    parser = build_parser()
+    args = parser.parse_args(argv)
+    return args.func(args, sys.stdout, sys.stderr)
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

influxdb_client_3/query/query_api.py

@@ -61,7 +61,9 @@ def __init__(self, root_certs_path: str,
 
     def _read_certs(self, path: str) -> bytes:
         with open(path, "rb") as certs_file:
-            return certs_file.read()
+            certs = certs_file.read()
+            # Normalize PEM line endings so behavior is stable across platforms.
+            return certs.replace(b"\r\n", b"\n").replace(b"\r", b"\n")
 
 
 class QueryApiOptionsBuilder(object):

setup.py

@@ -60,6 +60,9 @@ def get_version():
         ]
     },
     install_requires=requires,
+    entry_points={
+        'console_scripts': ['influx3 = influxdb_client_3.cli:main'],
+    },
     python_requires='>=3.9',
     classifiers=[
         'Development Status :: 4 - Beta',