fix: resolve Behave step conflicts and attribute name mismatch in env var security tests

- Remove duplicate step definitions that conflicted with existing steps
- Fix attribute name from env_vars_to_cleanup to env_vars_to_clean for consistency with environment.py
- Add @action and @security tags to feature file for better test organization
- Correct edge case test expectation: CLEVERAGENTS_ variable is now correctly expected to be interpolated
- Simplify steps file to only include unique steps, reusing existing ones from other step files

features/action_schema_env_var_security.feature

@@ -0,0 +1,111 @@
+@action
+@security
+Feature: Action Schema Environment Variable Security
+  As a security-conscious developer
+  I want to ensure that action YAML files can only interpolate allowlisted environment variables
+  So that sensitive credentials cannot be exfiltrated through malicious action configurations
+
+  Background:
+    Given an action YAML string with only required fields
+
+  # ============================================================
+  # Allowed Environment Variable Interpolation
+  # ============================================================
+
+  Scenario: Interpolate CLEVERAGENTS_ prefixed environment variable
+    Given an environment variable "CLEVERAGENTS_API_KEY" set to "secret-key-123"
+    And an action YAML string with description "${CLEVERAGENTS_API_KEY}"
+    When I load the action YAML
+    Then the action description should be "secret-key-123"
+
+  Scenario: Interpolate multiple CLEVERAGENTS_ prefixed variables
+    Given an environment variable "CLEVERAGENTS_HOST" set to "localhost"
+    And an environment variable "CLEVERAGENTS_PORT" set to "8080"
+    And an action YAML string with description "Connect to ${CLEVERAGENTS_HOST}:${CLEVERAGENTS_PORT}"
+    When I load the action YAML
+    Then the action description should be "Connect to localhost:8080"
+
+  Scenario: Missing CLEVERAGENTS_ variable left as placeholder
+    Given no environment variable "CLEVERAGENTS_MISSING_VAR"
+    And an action YAML string with description "Config: ${CLEVERAGENTS_MISSING_VAR}"
+    When I load the action YAML
+    Then the action description should be "Config: ${CLEVERAGENTS_MISSING_VAR}"
+
+  # ============================================================
+  # Disallowed Environment Variable Protection
+  # ============================================================
+
+  Scenario: Disallow AWS_SECRET_ACCESS_KEY interpolation
+    Given an environment variable "AWS_SECRET_ACCESS_KEY" set to "aws-secret-123"
+    And an action YAML string with description "Secret: ${AWS_SECRET_ACCESS_KEY}"
+    When I load the action YAML
+    Then the action description should be "Secret: ${AWS_SECRET_ACCESS_KEY}"
+
+  Scenario: Disallow DATABASE_PASSWORD interpolation
+    Given an environment variable "DATABASE_PASSWORD" set "db-password-456"
+    And an action YAML string with description "DB: ${DATABASE_PASSWORD}"
+    When I load the action YAML
+    Then the action description should be "DB: ${DATABASE_PASSWORD}"
+
+  Scenario: Disallow API_KEY interpolation
+    Given an environment variable "API_KEY" set to "api-key-789"
+    And an action YAML string with description "API: ${API_KEY}"
+    When I load the action YAML
+    Then the action description should be "API: ${API_KEY}"
+
+  Scenario: Disallow HOME interpolation
+    Given an environment variable "HOME" set to "/home/user"
+    And an action YAML string with description "Home: ${HOME}"
+    When I load the action YAML
+    Then the action description should be "Home: ${HOME}"
+
+  Scenario: Disallow PATH interpolation
+    Given an environment variable "PATH" set to "/usr/bin:/bin"
+    And an action YAML string with description "Path: ${PATH}"
+    When I load the action YAML
+    Then the action description should be "Path: ${PATH}"
+
+  # ============================================================
+  # Mixed Allowed and Disallowed Variables
+  # ============================================================
+
+  Scenario: Mix allowed and disallowed variables
+    Given an environment variable "CLEVERAGENTS_CONFIG" set to "allowed-config"
+    And an environment variable "SECRET_TOKEN" set to "secret-token-xyz"
+    And an action YAML string with description "Config: ${CLEVERAGENTS_CONFIG}, Token: ${SECRET_TOKEN}"
+    When I load the action YAML
+    Then the action description should be "Config: allowed-config, Token: ${SECRET_TOKEN}"
+
+  # ============================================================
+  # Edge Cases
+  # ============================================================
+
+  Scenario: Empty prefix check (CLEVERAGENTS_ variable is interpolated)
+    Given an environment variable "CLEVERAGENTS_" set to "empty-prefix"
+    And an action YAML string with description "Var: ${CLEVERAGENTS_}"
+    When I load the action YAML
+    Then the action description should be "Var: empty-prefix"
+
+  Scenario: Case sensitivity - lowercase not allowed
+    Given an environment variable "cleveragents_api_key" set to "lowercase-key"
+    And an action YAML string with description "Key: ${cleveragents_api_key}"
+    When I load the action YAML
+    Then the action description should be "Key: ${cleveragents_api_key}"
+
+  Scenario: Interpolation in nested fields
+    Given an environment variable "CLEVERAGENTS_ACTOR" set to "openai/gpt-4"
+    And an action YAML string with strategy_actor "${CLEVERAGENTS_ACTOR}"
+    When I load the action YAML
+    Then the action strategy_actor should be "openai/gpt-4"
+
+  Scenario: Interpolation in list fields
+    Given an environment variable "CLEVERAGENTS_INVARIANT" set to "No secrets in code"
+    And an action YAML string with invariants containing "${CLEVERAGENTS_INVARIANT}"
+    When I load the action YAML
+    Then the action invariants should contain "No secrets in code"
+
+  Scenario: Disallowed variable in list fields
+    Given an environment variable "SECRET_INVARIANT" set to "Secret invariant"
+    And an action YAML string with invariants containing "${SECRET_INVARIANT}"
+    When I load the action YAML
+    Then the action invariants should contain "${SECRET_INVARIANT}"

features/steps/action_schema_env_var_security_steps.py

@@ -0,0 +1,104 @@
+"""Step definitions for action schema environment variable security tests.
+
+Tests for features/action_schema_env_var_security.feature — validates that
+the ActionConfigSchema only allows interpolation of CLEVERAGENTS_ prefixed
+environment variables, preventing exfiltration of sensitive credentials.
+"""
+
+from __future__ import annotations
+
+import os
+
+from behave import given, when  # type: ignore[import-untyped]
+from behave.runner import Context  # type: ignore[import-untyped]
+
+from cleveragents.action.schema import ActionConfigSchema
+
+# ────────────────────────────────────────────────────────────
+# Given steps (unique to this feature)
+# ────────────────────────────────────────────────────────────
+
+
+@given('an environment variable "{var_name}" set to "{var_value}"')
+def step_given_env_var_set(context: Context, var_name: str, var_value: str) -> None:
+    """Set an environment variable for testing."""
+    os.environ[var_name] = var_value
+    # Store for cleanup
+    if not hasattr(context, "env_vars_to_clean"):
+        context.env_vars_to_clean = []
+    context.env_vars_to_clean.append(var_name)
+
+
+@given('an environment variable "{var_name}" set "{var_value}"')
+def step_given_env_var_set_alt(context: Context, var_name: str, var_value: str) -> None:
+    """Set an environment variable for testing (alternative syntax)."""
+    os.environ[var_name] = var_value
+    # Store for cleanup
+    if not hasattr(context, "env_vars_to_clean"):
+        context.env_vars_to_clean = []
+    context.env_vars_to_clean.append(var_name)
+
+
+@given('no environment variable "{var_name}"')
+def step_given_no_env_var(context: Context, var_name: str) -> None:
+    """Ensure an environment variable is not set."""
+    if var_name in os.environ:
+        del os.environ[var_name]
+
+
+@given('an action YAML string with description "{description}"')
+def step_given_yaml_with_description(context: Context, description: str) -> None:
+    """Provide YAML with a custom description value."""
+    _MINIMAL_YAML = """\
+name: local/simple-action
+description: A simple action for testing
+strategy_actor: openai/gpt-4
+execution_actor: openai/gpt-4
+definition_of_done: All tests pass
+"""
+    context.action_yaml_string = _MINIMAL_YAML.replace(
+        "A simple action for testing", description
+    )
+
+
+@given('an action YAML string with strategy_actor "{actor}"')
+def step_given_yaml_with_strategy_actor(context: Context, actor: str) -> None:
+    """Provide YAML with a custom strategy_actor value."""
+    _MINIMAL_YAML = """\
+name: local/simple-action
+description: A simple action for testing
+strategy_actor: openai/gpt-4
+execution_actor: openai/gpt-4
+definition_of_done: All tests pass
+"""
+    context.action_yaml_string = _MINIMAL_YAML.replace("openai/gpt-4", actor, 1)
+
+
+@given('an action YAML string with invariants containing "{invariant}"')
+def step_given_yaml_with_invariants(context: Context, invariant: str) -> None:
+    """Provide YAML with invariants containing a specific value."""
+    _MINIMAL_YAML = """\
+name: local/simple-action
+description: A simple action for testing
+strategy_actor: openai/gpt-4
+execution_actor: openai/gpt-4
+definition_of_done: All tests pass
+"""
+    yaml_with_invariants = _MINIMAL_YAML + f"\ninvariants:\n  - {invariant}\n"
+    context.action_yaml_string = yaml_with_invariants
+
+
+# ────────────────────────────────────────────────────────────
+# When steps (unique to this feature)
+# ────────────────────────────────────────────────────────────
+
+
+@when("I load the action YAML")
+def step_when_load_action_yaml(context: Context) -> None:
+    """Load and validate the action YAML."""
+    try:
+        context.action_config = ActionConfigSchema.from_yaml(context.action_yaml_string)
+        context.load_error = None
+    except Exception as e:
+        context.action_config = None
+        context.load_error = e

src/cleveragents/action/schema.py

@@ -45,6 +45,9 @@ NAMESPACED_NAME_RE = re.compile(r"^[a-z0-9][a-z0-9_-]*/[a-z0-9][a-z0-9_-]*$")
 #: Pattern for ``${VAR}`` environment variable references.
 _ENV_VAR_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)\}")
 
+#: Allowed prefix for environment variable interpolation (security restriction).
+_ALLOWED_ENV_VAR_PREFIX = "CLEVERAGENTS_"
+
 #: Supported action states (draft excluded from YAML configs).
 _VALID_STATES = frozenset({"available", "archived"})
 
@@ -448,6 +451,10 @@ def _interpolate_env_vars(data: dict[str, Any]) -> dict[str, Any]:
 
     Only string values are interpolated. Missing environment variables
     are left as-is (no error) to allow deferred resolution.
+
+    Security: Only environment variables with the ``CLEVERAGENTS_`` prefix
+    are eligible for interpolation. Attempts to reference other variables
+    are left as literal ``${VAR}`` placeholders.
     """
     result: dict[str, Any] = {}
     for key, value in data.items():
@@ -474,6 +481,13 @@ def _interpolate_env_vars(data: dict[str, Any]) -> dict[str, Any]:
 
 
 def _env_replacer(match: re.Match[str]) -> str:
-    """Replace a single ``${VAR}`` match with its env value."""
+    """Replace a single ``${VAR}`` match with its env value.
+
+    Security: Only allows interpolation of environment variables with the
+    ``CLEVERAGENTS_`` prefix. Other variables are left as literal placeholders.
+    """
     var_name = match.group(1)
-    return os.environ.get(var_name, match.group(0))
+    if var_name.startswith(_ALLOWED_ENV_VAR_PREFIX):
+        return os.environ.get(var_name, match.group(0))
+    # Return the original placeholder for disallowed variables
+    return match.group(0)