fix: validate closed-set preset params to reject typos (fixes #4116)

Seven Agent(...) preset params (output, execution, context, autonomy,
approval, learn, self_improve) silently fell back to defaults on a typo'd
preset name. Worst case: approval="read_onl" produced an empty deny set,
allowing all 17 dangerous tools instead of the intended read-only sandbox.

Wire the existing make_preset_error helper to these params via a small
validate_preset_string() in parse_utils.py plus a compact
_PRESET_STRING_PARAMS table and _validate_preset_params() loop run at the
top of the consolidated-params block, before every fast path that could
swallow the value. Free-form string params (knowledge, guardrails, skills,
runtime, auth) are deliberately excluded.

Co-authored-by: MervinPraison <[email protected]>

src/praisonai-agents/praisonaiagents/agent/agent.py

@@ -124,6 +124,7 @@ from ..config.param_resolver import resolve, ArrayMode
 from ..config.presets import (
     OUTPUT_PRESETS, EXECUTION_PRESETS, MEMORY_PRESETS, MEMORY_URL_SCHEMES,
     WEB_PRESETS, PLANNING_PRESETS, REFLECTION_PRESETS, CACHING_PRESETS,
+    CONTEXT_PRESETS, AUTONOMY_PRESETS,
     DEFAULT_OUTPUT_MODE,
 )
 from ..config.feature_configs import (
@@ -138,6 +139,64 @@ from ..config.feature_configs import (
 # (re-exported for backward compatibility) so OutputConfig.tool_output_limit,
 # ToolConfig.output_limit, and this constant cannot drift apart.
 
+# ============================================================================
+# Preset-string validation
+# ============================================================================
+# Agent params whose string form must name a preset from a CLOSED set. Each
+# entry maps the param name to a zero-arg callable returning the accepted
+# names, so registries outside praisonaiagents.config stay lazily imported —
+# the table is only consulted when the caller actually passed a string.
+#
+# Deliberately NOT listed (their string form is free-form, not a preset):
+#   knowledge= (source path/URL), guardrails= (LLM validator prompt),
+#   skills= (skill path/name), runtime= (open plugin registry), auth= (open
+#   provider registry validated loudly at use time).
+def _approval_preset_names():
+    """Accepted approval= strings: deny-set presets + PermissionMode aliases."""
+    from ..approval.registry import PERMISSION_PRESETS
+    from ..permissions.rules import _MODE_ALIASES
+    # "true"/"false" are legacy stringified bools accepted by the branch below.
+    return set(PERMISSION_PRESETS) | set(_MODE_ALIASES) | {"true", "false"}
+
+
+_PRESET_STRING_PARAMS = {
+    "output": lambda: OUTPUT_PRESETS.keys(),
+    "execution": lambda: EXECUTION_PRESETS.keys(),
+    "context": lambda: CONTEXT_PRESETS.keys(),
+    "autonomy": lambda: AUTONOMY_PRESETS.keys(),
+    "approval": _approval_preset_names,
+    # Mirrors the LearnMode branch in __init__.
+    "learn": lambda: ("disabled", "agentic", "propose"),
+    # Mirrors the self-improve mode branch in __init__.
+    "self_improve": lambda: (
+        "inline", "blocking", "sync", "background", "async",
+        "true", "on", "yes", "1", "false", "off", "no", "0",
+    ),
+}
+
+
+def _validate_preset_params(params):
+    """Fail loudly on a typo'd preset name instead of silently using defaults.
+
+    Args:
+        params: Mapping of param name -> raw value. Non-string values are
+            ignored; string values must name a preset from the closed set
+            declared in ``_PRESET_STRING_PARAMS``.
+
+    Raises:
+        ValueError: With a "Did you mean ...?" suggestion and the valid names.
+    """
+    from ..config.parse_utils import validate_preset_string
+
+    for name, value in params.items():
+        if not isinstance(value, str):
+            continue
+        # output= doubles as an output-file path (output="report.md").
+        if name == "output" and _is_file_path(value):
+            continue
+        validate_preset_string(name, value, _PRESET_STRING_PARAMS[name]())
+
+
 class ServerRegistry:
     """Registry for API server state per-port."""
     
@@ -945,7 +1004,20 @@ class Agent(GoalLoopMixin, SteeringMixin, SandboxMixin, SkillReviewMixin, Unifie
         # Uses unified resolver: Instance > Config > Array > String > Bool > Default
         # Note: Imports moved to module level for performance
         # ============================================================
-        
+        # Reject a typo'd preset name (e.g. output="streem", approval="read_onl")
+        # before any of the fast paths below silently fall back to defaults.
+        # memory/planning/reflection/web/caching/tool_search already raise via
+        # their own resolvers; this covers the params that did not.
+        _validate_preset_params({
+            "output": output,
+            "execution": execution,
+            "context": context,
+            "autonomy": autonomy,
+            "approval": approval,
+            "learn": learn,
+            "self_improve": self_improve,
+        })
+
         # Initialize extracted values with defaults
         user_id = None
         session_id = None

src/praisonai-agents/praisonaiagents/config/parse_utils.py

@@ -195,6 +195,39 @@ def make_preset_error(
     return ValueError(" ".join(msg_parts))
 
 
+def validate_preset_string(
+    param_name: str,
+    value: Any,
+    presets: Iterable[str],
+) -> None:
+    """
+    Raise a helpful error when a string does not name a known preset.
+
+    Non-string values pass through untouched, so callers can hand this the raw
+    parameter without pre-checking the type. Matching is case-insensitive and
+    ignores surrounding whitespace, mirroring the preset lookups performed by
+    the parameter resolvers.
+
+    Args:
+        param_name: Name of the parameter (for the error message)
+        value: Raw parameter value
+        presets: Valid preset names
+
+    Raises:
+        ValueError: If value is a string that is not a known preset
+    """
+    if not isinstance(value, str):
+        return
+
+    normalized = value.strip().lower()
+    presets_list = list(presets)
+    for preset in presets_list:
+        if preset.strip().lower() == normalized:
+            return
+
+    raise make_preset_error(param_name, value, presets_list)
+
+
 def is_policy_string(value: str) -> bool:
     """
     Check if a string is a policy specification. O(1) operation.

src/praisonai-agents/tests/unit/config/test_preset_typo_validation.py

@@ -0,0 +1,69 @@
+"""Preset-name typos must raise, not silently fall back to defaults.
+
+Regression test: Agent(output="streem") used to construct successfully with
+verbose=False (the silent default) instead of reporting the typo.
+"""
+import pytest
+
+from praisonaiagents import Agent
+
+# (param, typo, expected suggestion in the error message)
+TYPOED_PRESETS = [
+    ("output", "streem", "stream"),
+    ("execution", "balancd", "balanced"),
+    ("context", "sliding_windo", "sliding_window"),
+    ("autonomy", "full_atuo", "full_auto"),
+    ("approval", "read_onl", "read_only"),
+    ("learn", "agentik", "agentic"),
+    ("self_improve", "backgrond", "background"),
+    # Already-validated params — kept here so the guarantee is uniform.
+    ("memory", "postgress", "postgres"),
+    ("reflection", "thorogh", "thorough"),
+]
+
+
+@pytest.mark.parametrize("param,typo,suggestion", TYPOED_PRESETS)
+def test_typoed_preset_raises_with_suggestion(param, typo, suggestion):
+    with pytest.raises(ValueError) as exc:
+        Agent(instructions="t", **{param: typo})
+    msg = str(exc.value)
+    assert typo in msg
+    assert suggestion in msg
+
+
+VALID_PRESETS = [
+    ("output", "verbose"),
+    ("output", "silent"),
+    ("output", "VERBOSE"),  # case-insensitive lookup
+    ("execution", "fast"),
+    ("execution", "THOROUGH"),
+    ("context", "summarize"),
+    ("autonomy", "full_auto"),
+    ("approval", "read_only"),
+    ("approval", "plan"),
+    ("learn", "disabled"),
+    ("self_improve", "background"),
+]
+
+
+@pytest.mark.parametrize("param,value", VALID_PRESETS)
+def test_valid_preset_still_accepted(param, value):
+    assert Agent(instructions="t", **{param: value}) is not None
+
+
+def test_output_still_accepts_a_file_path():
+    """output= doubles as an output-file path; that escape hatch must survive."""
+    agent = Agent(instructions="t", output="report.md")
+    assert agent._output_file == "report.md"
+
+
+@pytest.mark.parametrize("value", [True, False, {"verbose": True}, None])
+def test_non_string_output_untouched(value):
+    assert Agent(instructions="t", output=value) is not None
+
+
+def test_freeform_string_params_are_not_validated():
+    """These take arbitrary identifiers, not presets — they must NOT raise."""
+    assert Agent(instructions="t", knowledge="notes.pdf") is not None
+    assert Agent(instructions="t", guardrails="Answer must cite a source.") is not None
+    assert Agent(instructions="t", runtime="my-plugin-runtime") is not None