chore: bump version to 0.1.7 and document env var support

- Add CHANGELOG entry for 0.1.7 (2026-03-05)
- Bump version in pyproject.toml and client.py
- Update basic_usage.py example to use BrainusAI() without manual env var handling
- Add tests for BRAINUS_API_KEY auto-read behaviour

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 0xneobyte

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.1.7] - 2026-03-05
+
+### Added
+
+- Automatic environment variable support: `api_key` is now optional and falls back to `BRAINUS_API_KEY` environment variable, enabling `BrainusAI()` without passing credentials explicitly
+
 ## [0.1.6] - 2025-12-12
 
 ### Fixed
@@ -56,6 +62,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Full type hints with Pydantic models
 - Async/await support
 
+[0.1.7]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.6...v0.1.7
+[0.1.6]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.5...v0.1.6
+[0.1.5]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.4...v0.1.5
 [0.1.4]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.3...v0.1.4
 [0.1.3]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.2...v0.1.3
 [0.1.2]: https://github.com/BrainUsLK/brainus-ai-python/compare/v0.1.1...v0.1.2

examples/basic_usage.py

@@ -1,19 +1,12 @@
 """Basic usage example for the Brainus AI Python SDK."""
 
 import asyncio
-import os
 from brainus_ai import BrainusAI
 
 
 async def main():
-    # Get API key from environment variable
-    api_key = os.getenv("BRAINUS_API_KEY")
-    if not api_key:
-        print("Error: BRAINUS_API_KEY environment variable not set")
-        return
-
-    # Initialize the client
-    async with BrainusAI(api_key=api_key) as client:
+    # Initialize client — reads BRAINUS_API_KEY from environment automatically
+    async with BrainusAI() as client:
         # Example 1: Query with no filters
         print("Example 1: Simple query")
         print("-" * 50)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "brainus-ai"
-version = "0.1.6"
+version = "0.1.7"
 description = "Official Python SDK for Brainus AI - RAG-powered educational content API"
 readme = "README.md"
 license = {text = "MIT"}

src/brainus_ai/client.py

@@ -2,9 +2,13 @@
 
 from __future__ import annotations
 
+import os
+
 import httpx
 from typing import Any
 
+_SDK_VERSION = "0.1.7"
+
 from .exceptions import (
     AuthenticationError,
     RateLimitError,
@@ -30,7 +34,7 @@ class BrainusAI:
 
     def __init__(
         self,
-        api_key: str,
+        api_key: str | None = None,
         base_url: str = "https://api.brainus.lk",
         timeout: float = 30.0,
         max_retries: int = 3,
@@ -39,13 +43,18 @@ def __init__(
         Initialize the Brainus AI client.
 
         Args:
-            api_key: Your Brainus AI API key (brainus_...)
+            api_key: Your Brainus AI API key (brainus_...). If not provided,
+                reads from the BRAINUS_API_KEY environment variable.
             base_url: Base URL for the API (default: production gateway)
             timeout: Request timeout in seconds
             max_retries: Maximum number of retry attempts for failed requests
         """
+        if api_key is None:
+            api_key = os.environ.get("BRAINUS_API_KEY")
         if not api_key or not api_key.startswith("brainus_"):
-            raise AuthenticationError("Invalid API key format. Expected format: brainus_...")
+            raise AuthenticationError(
+                "Invalid API key. Pass api_key or set the BRAINUS_API_KEY environment variable."
+            )
 
         self.api_key = api_key
         self.base_url = base_url.rstrip("/")
@@ -57,7 +66,7 @@ def __init__(
             headers={
                 "X-API-Key": self.api_key,
                 "Content-Type": "application/json",
-                "User-Agent": "brainus-ai-python/0.1.0",
+                "User-Agent": f"brainus-ai-python/{_SDK_VERSION}",
             },
             timeout=httpx.Timeout(timeout),
             transport=httpx.AsyncHTTPTransport(retries=max_retries),

tests/test_client.py

@@ -53,3 +53,18 @@ def test_default_max_retries(self):
     def test_custom_max_retries(self):
         client = BrainusAI(api_key="brainus_abc123", max_retries=5)
         assert client.max_retries == 5
+
+    def test_reads_api_key_from_env(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setenv("BRAINUS_API_KEY", "brainus_from_env_123")
+        client = BrainusAI()
+        assert client.api_key == "brainus_from_env_123"
+
+    def test_explicit_key_takes_priority_over_env(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setenv("BRAINUS_API_KEY", "brainus_from_env_123")
+        client = BrainusAI(api_key="brainus_explicit_456")
+        assert client.api_key == "brainus_explicit_456"
+
+    def test_raises_when_no_key_and_no_env(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.delenv("BRAINUS_API_KEY", raising=False)
+        with pytest.raises(AuthenticationError):
+            BrainusAI()