diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3041973..fab4046 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 2.10.12
+
+### Fixed: reject retired API tokens before use
+
+- The CLI rejects the retired API credential before HTTP or reachability
+  requests are created.
+
 ## 2.10.11
 
 ### Changed: bump pinned @coana-tech/cli to 15.12.7
diff --git a/pyproject.toml b/pyproject.toml
index 36d7e47..0b5c1ba 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "socketsecurity"
-version = "2.10.11"
+version = "2.10.12"
 requires-python = ">= 3.11"
 license = {"file" = "LICENSE"}
 dependencies = [
diff --git a/socketsecurity/__init__.py b/socketsecurity/__init__.py
index a057239..025b61a 100644
--- a/socketsecurity/__init__.py
+++ b/socketsecurity/__init__.py
@@ -1,3 +1,3 @@
 __author__ = 'socket.dev'
-__version__ = '2.10.11'
+__version__ = '2.10.12'
 USER_AGENT = f'SocketPythonCLI/{__version__}'
diff --git a/socketsecurity/config.py b/socketsecurity/config.py
index 1f107cf..cb87432 100644
--- a/socketsecurity/config.py
+++ b/socketsecurity/config.py
@@ -9,6 +9,27 @@
 from socketdev import INTEGRATION_TYPES, IntegrationType
 
 from socketsecurity import __version__
+from socketsecurity.retired_api_token import reject_retired_api_token
+
+API_TOKEN_ENVIRONMENT_VARIABLES = (
+    "SOCKET_SECURITY_API_KEY",
+    "SOCKET_SECURITY_API_TOKEN",
+    "SOCKET_API_KEY",
+    "SOCKET_API_TOKEN",
+)
+
+
+def select_api_token(
+    environment: dict[str, str], argument_token: Optional[str]
+) -> Optional[str]:
+    return next(
+        (
+            environment[name]
+            for name in API_TOKEN_ENVIRONMENT_VARIABLES
+            if environment.get(name)
+        ),
+        argument_token,
+    )
 
 
 def get_plugin_config_from_env(prefix: str) -> dict:
@@ -272,13 +293,8 @@ def from_args(cls, args_list: Optional[List[str]] = None) -> 'CliConfig':
             )
 
         # Get API token from env or args (check multiple env var names)
-        api_token = (
-            os.getenv("SOCKET_SECURITY_API_KEY") or
-            os.getenv("SOCKET_SECURITY_API_TOKEN") or
-            os.getenv("SOCKET_API_KEY") or
-            os.getenv("SOCKET_API_TOKEN") or
-            args.api_token
-        )
+        api_token = select_api_token(os.environ, args.api_token)
+        reject_retired_api_token(api_token)
 
         # --sarif-file implies --enable-sarif
         if args.sarif_file:
diff --git a/socketsecurity/core/cli_client.py b/socketsecurity/core/cli_client.py
index 405a744..6af19d0 100644
--- a/socketsecurity/core/cli_client.py
+++ b/socketsecurity/core/cli_client.py
@@ -6,6 +6,7 @@
 import requests
 
 from socketsecurity import USER_AGENT
+from socketsecurity.retired_api_token import reject_retired_api_token
 
 from .exceptions import APIFailure
 from .socket_config import SocketConfig
@@ -14,6 +15,7 @@
 
 class CliClient:
     def __init__(self, config: SocketConfig):
+        reject_retired_api_token(config.api_key)
         self.config = config
         self._encoded_key = self._encode_key(config.api_key)
 
diff --git a/socketsecurity/core/socket_config.py b/socketsecurity/core/socket_config.py
index 1089a53..57340a3 100644
--- a/socketsecurity/core/socket_config.py
+++ b/socketsecurity/core/socket_config.py
@@ -6,6 +6,7 @@
 from socketdev.core.issues import AllIssues
 
 from socketsecurity import __version__
+from socketsecurity.retired_api_token import reject_retired_api_token
 
 default_exclude_dirs = {
     "node_modules", "bower_components", "jspm_packages",   # JS/TS
@@ -39,6 +40,8 @@ def __post_init__(self):
         if not self.api_key:
             raise ValueError("API key is required")
 
+        reject_retired_api_token(self.api_key)
+
         if self.timeout <= 0:
             raise ValueError("Timeout must be a positive integer")
 
diff --git a/socketsecurity/core/tools/reachability.py b/socketsecurity/core/tools/reachability.py
index 1dc90b6..9241210 100644
--- a/socketsecurity/core/tools/reachability.py
+++ b/socketsecurity/core/tools/reachability.py
@@ -13,6 +13,7 @@
 from socketdev import socketdev
 
 from socketsecurity import __version__
+from socketsecurity.retired_api_token import reject_retired_api_token
 
 log = logging.getLogger(__name__)
 
@@ -51,6 +52,7 @@ def _build_caller_user_agent() -> str:
 
 class ReachabilityAnalyzer:
     def __init__(self, sdk: socketdev, api_token: str):
+        reject_retired_api_token(api_token)
         self.sdk = sdk
         self.api_token = api_token
     
@@ -137,6 +139,7 @@ def run_reachability_analysis(
         Returns:
             Dict containing scan_id and report_path
         """
+        reject_retired_api_token(self.api_token)
         # Build the coana CLI arguments (everything after the package spec). The launcher
         # (npx, or the npm-install + node fallback) is chosen in _spawn_coana() below.
         coana_args = ["run", "."]
diff --git a/socketsecurity/retired_api_token.py b/socketsecurity/retired_api_token.py
new file mode 100644
index 0000000..2e2f232
--- /dev/null
+++ b/socketsecurity/retired_api_token.py
@@ -0,0 +1,28 @@
+import hashlib
+import hmac
+from typing import Optional
+
+RETIRED_API_TOKEN_SHA256 = (
+    "9cab58b24140ee12c08e265729d246f9200f8ef9b1d884f90c06c4e6b69adf18"
+)
+RETIRED_API_TOKEN_ERROR = (
+    "This API token has been retired. Create a new API token in Socket "
+    "and update your configuration."
+)
+
+
+# Fingerprint identifies a retired credential; it is not a password verifier.
+def _matches_retired_digest(token: Optional[str], digest: str) -> bool:
+    if token is None:
+        return False
+    token_digest = hashlib.sha256(token.strip().encode("utf-8")).hexdigest()
+    return hmac.compare_digest(token_digest, digest)
+
+
+def _reject_retired_api_token(token: Optional[str], digest: str) -> None:
+    if _matches_retired_digest(token, digest):
+        raise ValueError(RETIRED_API_TOKEN_ERROR)
+
+
+def reject_retired_api_token(token: Optional[str]) -> None:
+    _reject_retired_api_token(token, RETIRED_API_TOKEN_SHA256)
diff --git a/tests/unit/test_retired_api_token.py b/tests/unit/test_retired_api_token.py
new file mode 100644
index 0000000..7c14ac8
--- /dev/null
+++ b/tests/unit/test_retired_api_token.py
@@ -0,0 +1,73 @@
+import hashlib
+
+import pytest
+from socketdev import socketdev
+
+from socketsecurity.config import (
+    API_TOKEN_ENVIRONMENT_VARIABLES,
+    CliConfig,
+    select_api_token,
+)
+from socketsecurity.core.cli_client import CliClient
+from socketsecurity.core.socket_config import SocketConfig
+from socketsecurity.core.tools.reachability import ReachabilityAnalyzer
+from socketsecurity.retired_api_token import (
+    RETIRED_API_TOKEN_ERROR,
+    _matches_retired_digest,
+    _reject_retired_api_token,
+)
+
+
+def test_retired_api_token_rejection_redacts_token_and_digest():
+    token = "synthetic-retired-token"
+    digest = hashlib.sha256(token.encode()).hexdigest()
+
+    with pytest.raises(ValueError) as exc_info:
+        _reject_retired_api_token(token, digest)
+
+    assert str(exc_info.value) == RETIRED_API_TOKEN_ERROR
+    assert token not in str(exc_info.value)
+    assert digest not in str(exc_info.value)
+    assert _matches_retired_digest(f" {token} ", digest)
+
+
+def test_cli_config_preserves_token_environment_precedence(monkeypatch):
+    for name in API_TOKEN_ENVIRONMENT_VARIABLES:
+        monkeypatch.delenv(name, raising=False)
+    monkeypatch.setenv(API_TOKEN_ENVIRONMENT_VARIABLES[0], "first-env-token")
+    monkeypatch.setenv(API_TOKEN_ENVIRONMENT_VARIABLES[1], "second-env-token")
+
+    config = CliConfig.from_args(["--api-token", "argument-token"])
+
+    assert config.api_token == "first-env-token"
+
+
+def test_cli_config_uses_argument_when_token_environment_is_empty(monkeypatch):
+    for name in API_TOKEN_ENVIRONMENT_VARIABLES:
+        monkeypatch.delenv(name, raising=False)
+
+    config = CliConfig.from_args(["--api-token", "argument-token"])
+
+    assert config.api_token == "argument-token"
+
+
+def test_cli_http_and_reachability_construction_accept_safe_token_without_network():
+    token = "synthetic-safe-token"
+    config = SocketConfig(api_key=token)
+    client = CliClient(config)
+    sdk = socketdev(token=token)
+    analyzer = ReachabilityAnalyzer(sdk, token)
+
+    assert client.config.api_key == token
+    assert analyzer.api_token == token
+
+
+@pytest.mark.parametrize("token", [None, "different-token"])
+def test_nonretired_api_token_is_accepted(token):
+    digest = hashlib.sha256(b"synthetic-retired-token").hexdigest()
+    _reject_retired_api_token(token, digest)
+
+
+@pytest.mark.parametrize("name", API_TOKEN_ENVIRONMENT_VARIABLES)
+def test_each_cli_environment_source_is_supported(name):
+    assert select_api_token({name: "selected-token"}, "argument-token") == "selected-token"
diff --git a/uv.lock b/uv.lock
index 6df942c..7aeecc9 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1292,7 +1292,7 @@ wheels = [
 
 [[package]]
 name = "socketsecurity"
-version = "2.10.11"
+version = "2.10.12"
 source = { editable = "." }
 dependencies = [
     { name = "beautifulsoup4" },