diff --git a/instructions.md b/instructions.md
index 9a66cbb..c815122 100644
--- a/instructions.md
+++ b/instructions.md
@@ -45,13 +45,6 @@ The tasks should be completed in the following order to ensure proper dependenci
 
 ### 3. Configuration Management
 
-#### [] Implement configuration models
-
--   []Create `src/server/models/config.py`
--   []Define ConfigResponse, ConfigUpdate models
--   []Add SchedulerConfig, LoggingConfig models
--   []Include ValidationResult model
-
 #### [] Create configuration service
 
 -   []Create `src/server/services/config_service.py`
diff --git a/src/server/models/config.py b/src/server/models/config.py
new file mode 100644
index 0000000..f5b8368
--- /dev/null
+++ b/src/server/models/config.py
@@ -0,0 +1,66 @@
+from typing import List, Optional
+
+from pydantic import BaseModel, Field
+
+
+class SchedulerConfig(BaseModel):
+    enabled: bool = Field(
+        default=True, description="Whether the scheduler is enabled"
+    )
+    interval_minutes: int = Field(
+        default=60, ge=1, description="Scheduler interval in minutes"
+    )
+
+    # ge=1 on the Field enforces a positive interval; no custom validator
+    # is required.
+
+
+class LoggingConfig(BaseModel):
+    level: str = Field(default="INFO", description="Logging level")
+    file: Optional[str] = Field(
+        default=None, description="Optional file path for log output"
+    )
+    max_bytes: Optional[int] = Field(
+        default=None, ge=0, description="Max bytes per log file for rotation"
+    )
+    backup_count: Optional[int] = Field(
+        default=3, ge=0, description="Number of rotated log files to keep"
+    )
+
+
+class ValidationResult(BaseModel):
+    valid: bool = Field(..., description="Whether the configuration is valid")
+    errors: Optional[List[str]] = Field(
+        default_factory=list, description="List of validation error messages"
+    )
+
+
+class ConfigResponse(BaseModel):
+    scheduler: SchedulerConfig
+    logging: LoggingConfig
+    other: Optional[dict] = Field(
+        default_factory=dict, description="Other arbitrary config values"
+    )
+
+
+class ConfigUpdate(BaseModel):
+    scheduler: Optional[SchedulerConfig] = None
+    logging: Optional[LoggingConfig] = None
+    other: Optional[dict] = None
+
+    def apply_to(self, current: ConfigResponse) -> ConfigResponse:
+        """Return a new ConfigResponse with updates applied to the current
+        config.
+        """
+        # Use model_dump for compatibility with Pydantic v2+ (avoids deprecation)
+        data = current.model_dump()
+        if self.scheduler is not None:
+            data["scheduler"] = self.scheduler.model_dump()
+        if self.logging is not None:
+            data["logging"] = self.logging.model_dump()
+        if self.other is not None:
+            # shallow merge
+            merged = dict(current.other or {})
+            merged.update(self.other)
+            data["other"] = merged
+        return ConfigResponse(**data)
diff --git a/tests/unit/test_config_models.py b/tests/unit/test_config_models.py
new file mode 100644
index 0000000..dfbd085
--- /dev/null
+++ b/tests/unit/test_config_models.py
@@ -0,0 +1,49 @@
+import pytest
+
+from src.server.models.config import (
+    ConfigResponse,
+    ConfigUpdate,
+    LoggingConfig,
+    SchedulerConfig,
+    ValidationResult,
+)
+
+
+def test_scheduler_defaults_and_validation():
+    sched = SchedulerConfig()
+    assert sched.enabled is True
+    assert sched.interval_minutes == 60
+
+    with pytest.raises(ValueError):
+        SchedulerConfig(interval_minutes=0)
+
+
+def test_logging_config_defaults_and_values():
+    log = LoggingConfig()
+    assert log.level == "INFO"
+    assert log.file is None
+    assert log.backup_count == 3
+
+
+def test_config_update_apply_to():
+    base = ConfigResponse(
+        scheduler=SchedulerConfig(),
+        logging=LoggingConfig(),
+        other={"a": 1},
+    )
+
+    upd = ConfigUpdate(scheduler=SchedulerConfig(enabled=False, interval_minutes=30))
+    new = upd.apply_to(base)
+    assert new.scheduler.enabled is False
+    assert new.scheduler.interval_minutes == 30
+
+    upd2 = ConfigUpdate(other={"b": 2})
+    new2 = upd2.apply_to(base)
+    assert new2.other["a"] == 1
+    assert new2.other["b"] == 2
+
+
+def test_validation_result_model():
+    vr = ValidationResult(valid=True)
+    assert vr.valid is True
+    assert isinstance(vr.errors, list)