diff --git a/src/git_draft/bots/openai.py b/src/git_draft/bots/openai.py
index b0c9919..7e994a5 100644
--- a/src/git_draft/bots/openai.py
+++ b/src/git_draft/bots/openai.py
@@ -1,6 +1,6 @@
 """OpenAI API-backed bots
 
-They can be used with services other than OpenAPI as long as them implement a
+They can be used with services other than OpenAI as long as them implement a
 sufficient subset of the API. For example the `completions_bot` only requires
 tools support.
 
@@ -15,13 +15,12 @@
 from collections.abc import Mapping, Sequence
 import json
 import logging
-import os
 from pathlib import PurePosixPath
 from typing import Any, Self, TypedDict, override
 
 import openai
 
-from ..common import JSONObject, reindent
+from ..common import JSONObject, config_string, reindent
 from .common import Action, Bot, Goal, Toolbox
 
 
@@ -37,10 +36,7 @@ def completions_bot(
     model: str = _DEFAULT_MODEL,
 ) -> Bot:
     """Compatibility-mode bot, uses completions with function calling"""
-    if api_key and api_key.startswith("$"):
-        api_key = os.environ[api_key[1:]]
-    client = openai.OpenAI(api_key=api_key, base_url=base_url)
-    return _CompletionsBot(client, model)
+    return _CompletionsBot(_new_client(api_key, base_url), model)
 
 
 def threads_bot(
@@ -49,8 +45,14 @@ def threads_bot(
     model: str = _DEFAULT_MODEL,
 ) -> Bot:
     """Beta bot, uses assistant threads with function calling"""
-    client = openai.OpenAI(api_key=api_key, base_url=base_url)
-    return _ThreadsBot.create(client, model)
+    return _ThreadsBot.create(_new_client(api_key, base_url), model)
+
+
+def _new_client(api_key: str | None, base_url: str | None) -> openai.OpenAI:
+    return openai.OpenAI(
+        api_key=config_string(api_key) if api_key else None,
+        base_url=base_url,
+    )
 
 
 class _ToolsFactory:
diff --git a/src/git_draft/common.py b/src/git_draft/common.py
index c8f9ed0..d21b533 100644
--- a/src/git_draft/common.py
+++ b/src/git_draft/common.py
@@ -6,6 +6,7 @@
 import dataclasses
 import itertools
 import logging
+import os
 from pathlib import Path
 import random
 import sqlite3
@@ -73,6 +74,11 @@ class BotConfig:
     pythonpath: str | None = None
 
 
+def config_string(arg: str) -> str:
+    """Dereferences environment value if the input starts with `$`"""
+    return os.environ[arg[1:]] if arg and arg.startswith("$") else arg
+
+
 _random = random.Random()
 _alphabet = string.ascii_lowercase + string.digits
 
diff --git a/tests/git_draft/common_test.py b/tests/git_draft/common_test.py
index 7cd44f6..cc158a9 100644
--- a/tests/git_draft/common_test.py
+++ b/tests/git_draft/common_test.py
@@ -62,6 +62,16 @@ def test_load_default(self) -> None:
         assert config.log_level == logging.INFO
 
 
+class TestConfigString:
+    def test_literal(self) -> None:
+        assert sut.config_string("") == ""
+        assert sut.config_string("abc") == "abc"
+
+    def test_evar(self, monkeypatch) -> None:
+        monkeypatch.setenv("FOO", "111")
+        assert sut.config_string("$FOO") == "111"
+
+
 @pytest.mark.parametrize(
     "text,width,want",
     [