diff --git a/DEVELOPER_README.md b/DEVELOPER_README.md
index 6ceae07..3eee042 100644
--- a/DEVELOPER_README.md
+++ b/DEVELOPER_README.md
@@ -1,56 +1,377 @@
-# Checker Function Development Guide
+# Checker Function Developer Guide
 
-## Setup
+This document provides technical details for developers working on the Speckle Checker Automate function.
 
-1. Install dependencies:
+## Project Overview
+
+The Checker function enables validation of Speckle objects against user-defined rules in a spreadsheet. It's designed to
+be flexible, supporting various object schemas including both v2 and v3 Speckle APIs.
+
+## Setup Development Environment
+
+### Prerequisites
+
+- Python 3.10+
+- Poetry for dependency management
+
+### Installation
+
+1. Clone the repository
+2. Install dependencies:
+   ```bash
+   poetry install
+   ```
+3. Activate the virtual environment:
+   ```bash
+   poetry shell
+   ```
+
+### Test Automation Environment
+
+The project uses Speckle's [Test Automation feature](https://speckle.guide/automate/function-testing.html) to run
+integration tests against real Speckle data. This provides a sandboxed environment to validate the function's business
+logic without triggering actual automations.
+
+#### Setting Up a Test Automation
+
+1. Navigate to your Speckle project
+2. Go to the **Automations** tab
+3. Click **New Automation**
+4. Select **Create Test Automation** in the bottom left
+5. Follow the configuration steps
+
+Note: To create a test automation, you must:
+
+- Be an owner of the Speckle project
+- Have published this function to the Function Library
+- Have at least one release for the function
+
+#### Environment Configuration
+
+For local integration testing, create a `.env` file in the project root with these variables:
+
+```
+# Your Personal Access Token from Speckle
+SPECKLE_TOKEN=your_speckle_token
+
+# The Speckle server URL
+SPECKLE_SERVER_URL=https://app.speckle.systems
+
+# From the test automation URL: /projects/[project-id]/automations/[automation-id]
+SPECKLE_PROJECT_ID=your_project_id
+SPECKLE_AUTOMATION_ID=your_automation_id
+```
+
+This configuration allows the test suite to:
+
+1. Connect to your test automation via the Speckle API
+2. Run the function locally against real Speckle data
+3. Submit results to the test automation for validation
+
+For detailed instructions, refer to
+the [official documentation on function testing](https://speckle.guide/automate/function-testing.html#how-to-create-a-test-automation).
+
+#### Running Integration Tests
+
+With the `.env` file configured:
 
 ```bash
-poetry shell && poetry install
+# Run the integration tests
+pytest test_function.py
 ```
 
-2. Configure `.env`:
+The SDK utilities will automatically:
 
-```
-SPECKLE_TOKEN=your_speckle_token
-SPECKLE_SERVER_URL=app.speckle.systems
+- Connect to your test automation
+- Execute your function with the specified test data
+- Submit results back to Speckle
+
+Test results will be visible on the automation page in the Speckle UI.
+
+#### Unit Tests
+
+For unit tests that don't require a full Speckle connection, you can run:
+
+```bash
+# Run unit tests only
+pytest test_comparisons.py test_rule_processing.py
 ```
 
-Get test automation details from app.speckle.systems
+Note: The `.env` file should never be committed to version control (it's included in .gitignore)
 
 ## Project Structure
 
-- `function.py`: Main business logic
-- `rules.py`: Rule definitions and processing
-- `inputs.py`: Function input schema
-- `helpers.py`: Utility functions
-- `spreadsheet.py`: TSV handling
+```
+├── main.py                  # Entry point for Automate
+├── src/
+│   ├── function.py          # Main function logic
+│   ├── inputs.py            # Function input schema
+│   ├── helpers.py           # Utility functions
+│   ├── filters.py           # Object filtering functions
+│   ├── rules.py             # Rule definitions and property handling
+│   ├── predicates.py        # Predicate mapping for spreadsheet values
+│   ├── rule_processor.py    # Rule application and result handling
+│   └── spreadsheet.py       # TSV file parsing
+├── tests/
+│   ├── conftest.py          # Test fixtures
+│   ├── test_function.py     # Main function tests
+│   ├── test_comparisons.py  # Value comparison tests
+│   ├── test_parameters.py   # Parameter handling tests
+│   └── test_rule_processing.py  # Rule processing tests
+├── pyproject.toml           # Project dependencies
+└── poetry.lock              # Locked dependencies
+```
+
+## Core Components
+
+### 1. Function Execution Flow
+
+The main execution flow is defined in `function.py`:
+
+1. `automate_function()` receives context and inputs from Automate
+2. Retrieves Speckle objects via `automate_context.receive_version()`
+3. Flattens the object tree using `flatten_base()`
+4. Loads rules from the spreadsheet URL via `read_rules_from_spreadsheet()`
+5. Applies rules to objects using `apply_rules_to_objects()`
+6. Reports results via the Automate context
+
+### 2. Rule Processing
+
+Rules are processed through several stages:
+
+1. **Spreadsheet Parsing** (`spreadsheet.py`):
+    - Reads TSV data
+    - Groups rules by rule number
+    - Validates rule structure
+
+2. **Rule Application** (`rule_processor.py`):
+    - Processes rule logic (WHERE, AND, CHECK)
+    - Evaluates conditions against objects
+    - Attaches results to objects in Automate context
+
+3. **Property Rules** (`rules.py`):
+    - Handles property lookups in objects
+    - Implements comparison logic
+    - Supports both v2 and v3 Speckle schemas
+
+### 3. Property Access System
+
+The system uses a flexible property access mechanism that works with different Speckle schemas:
+
+- **V2 Schema**: Properties in `parameters` dictionary with internal definition names
+- **V3 Schema**: Properties in nested `properties.Parameters` structure
+
+The `PropertyRules` class provides methods to:
+
+- Find properties by path or name
+- Extract values with appropriate type conversion
+- Perform comparisons with tolerance and type handling
+
+## Test-Driven Development for Rules
+
+The test infrastructure is designed to support Test-Driven Development (TDD) when creating new rules or extending
+functionality. This approach is especially powerful for rule development as it allows you to verify behavior against
+known test objects.
+
+### Using Test Fixtures for Rule Development
+
+The `conftest.py` file contains test fixtures that provide sample Speckle objects for testing:
+
+```python
+@pytest.fixture
+def v2_wall():
+    """Creates a v2-style Speckle wall object"""
+    wall = Base()
+    wall.id = "cdb18060dc48281909e94f0f1d8d3cc0"
+    wall.type = "W30(Fc24)"
+    wall.units = "mm"
+    wall.family = "Basic Wall"
+    wall.height = 1400
+    wall.flipped = False
+    wall.category = "Walls"
+    # ... more properties
+
+    return wall
+
+
+@pytest.fixture
+def v3_wall():
+    """Creates a v3-style Speckle wall object"""
+    wall = Base()
+    wall.id = "46f06fef727d64a0bbcbd7ced51e0cd2"
+    wall.name = "Walls - W30(Fc24)"
+    wall.type = "W30(Fc24)"
+    wall.units = "mm"
+    wall.family = "Basic Wall"
+    # ... more properties
+
+    return wall
+```
+
+These fixtures create standardized test objects that represent different Speckle schema versions, allowing you to test
+rule behavior consistently.
+
+### TDD Workflow for New Rules
+
+When developing a new rule or predicate, follow this TDD approach:
+
+1. **Add test fixtures**: First, expand `conftest.py` with representative objects that your rule will process
+
+2. **Write tests first**: Create test cases in a test file (e.g., `test_my_rule.py`):
+   ```python
+   def test_new_wall_rule(v2_wall, v3_wall):
+       """Test a new rule that checks wall thickness requirements"""
+       # Test with v2 schema
+       assert PropertyRules.is_new_wall_check(v2_wall, "width", "300")
+       
+       # Test with v3 schema
+       assert PropertyRules.is_new_wall_check(v3_wall, "Width", "300")
+       
+       # Test failure case
+       v2_wall.parameters["WALL_ATTR_WIDTH_PARAM"].value = 200
+       assert not PropertyRules.is_new_wall_check(v2_wall, "width", "300")
+   ```
+
+3. **Implement the rule**: Add the new rule method to the `PropertyRules` class in `rules.py`:
+   ```python
+   @staticmethod
+   def is_new_wall_check(speckle_object: Base, parameter_name: str, expected_value: str) -> bool:
+       """Checks if a wall meets specific thickness requirements"""
+       parameter_value = PropertyRules.get_parameter_value(speckle_object, parameter_name)
+       # Implement rule logic
+       return result
+   ```
+
+4. **Add to predicate mapping**: Register your new rule in `predicates.py`:
+   ```python
+   PREDICATE_METHOD_MAP = {
+       # Existing predicates...
+       "new_wall_check": PropertyRules.is_new_wall_check.__name__,
+   }
+   ```
+
+5. **Run tests to verify**:
+   ```bash
+   pytest test_my_rule.py -v
+   ```
+
+### Creating Comprehensive Test Objects
+
+For the most effective testing, your test objects in `conftest.py` should:
+
+1. **Include diverse objects**: Walls, columns, beams, etc.
+2. **Cover edge cases**: Null values, missing properties, special characters
+3. **Represent both schemas**: Include both v2 and v3 format objects
+4. **Include real-world examples**: Extract sample objects from actual projects
+
+You can extract real objects for testing using:
+
+```python
+# Example code to extract and save real objects for test fixtures
+from specklepy.api import operations
+from specklepy.api.client import SpeckleClient
+from specklepy.transports.server import ServerTransport
+
+client = SpeckleClient(host="app.speckle.systems")
+client.authenticate_with_token(token)
+
+transport = ServerTransport(client=client, stream_id="stream_id")
+obj = operations.receive("object_id", transport)
+
+# Print structure to help with fixture creation
+print(obj.get_member_names())
+print(obj.get_dynamic_member_names())
+```
+
+By following this TDD approach and maintaining comprehensive test fixtures, you can develop robust rules that work
+reliably across different object schemas and handle edge cases appropriately.
 
 ## Testing
 
+### Running Tests
+
 ```bash
-poetry run pytest
+# Run all tests
+pytest
+
+# Run specific test file
+pytest tests/test_parameters.py
+
+# Run with coverage
+pytest --cov=src
 ```
 
-## Extending Rules
+### Test Data
 
-1. Add new predicate to `input_predicate_mapping` in `rules.py`
-2. Create corresponding method in `PropertyRules` class
-3. Update tests
+Test fixtures in `conftest.py` provide sample objects:
 
-## Building
+- `v2_wall`: Wall object in v2 schema
+- `v3_wall`: Wall object in v3 schema
 
-The function is packaged as a Docker container:
+### Manual Testing with Real Data
 
-```bash
-docker build -f ./Dockerfile -t checker .
-```
+For testing with real Speckle data:
 
-## Local Testing
+```python
+from specklepy.api import operations
+from specklepy.api.client import SpeckleClient
+from specklepy.api.credentials import get_account_from_token
+from specklepy.transports.server import ServerTransport
 
-```bash
-docker run --rm checker python -u main.py run [automation_data] [parameters] [token]
+client = SpeckleClient(host="app.speckle.systems")
+account = get_account_from_token(token, "app.speckle.systems")
+client.authenticate_with_account(account)
+
+transport = ServerTransport(client=client, stream_id="your_stream_id")
+commit = client.commit.get(stream_id="your_stream_id", commit_id="your_commit_id")
+obj = operations.receive(commit.referencedObject, transport)
 ```
 
 ## Deployment
 
-Create a GitHub release to trigger deployment to Speckle Automate.
\ No newline at end of file
+The function is deployed through GitHub Actions:
+
+1. Create a GitHub release to trigger the build workflow
+2. The workflow builds the necessary artifacts and pushes them to the Speckle Automate registry
+3. The function becomes available in the Speckle Automate UI
+
+## Performance Considerations
+
+- **Large Object Trees**: When processing large models, use aggressive filtering with WHERE clauses
+- **Rule Complexity**: Minimize the number of nested property lookups
+- **Memory Usage**: Be aware of object reference handling and avoid deep copies
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Rule not matching expected objects**:
+    - Check property paths for the specific object type
+    - Verify data types (strings vs. numbers)
+    - Enable debug logging
+
+2. **Slow performance**:
+    - Check for inefficient property lookups
+    - Add more specific WHERE filters to reduce object set
+
+3. **Docker build failures**:
+    - Check dependency compatibility
+    - Verify Python version requirements
+
+## Contributing
+
+1. Create a branch for your feature or fix
+2. Add tests for new functionality
+3. Update documentation
+4. Submit a pull request
+5. Ensure CI tests pass
+
+## Future Development
+
+Potential improvements:
+
+- Support for more complex rule logic (OR conditions)
+- UI-based rule editor
+- Result visualization tools
+- Performance optimizations for large models
+- Support for referencing other objects in rules
\ No newline at end of file
diff --git a/README.md b/README.md
index e052b82..f76f1a4 100644
--- a/README.md
+++ b/README.md
@@ -1,36 +1,121 @@
-# Public Function: Checker
+# Speckle Checker
 
-Validate Speckle objects against configurable rules using spreadsheet definitions.
+Speckle Checker is an Automate function that validates Speckle objects against configurable rules defined in a
+spreadsheet. This approach provides a flexible way to implement quality checks without coding, making it accessible to
+all team members.
 
-## Usage
+## Overview
 
-1. Access the template Google Sheet [link needed]
-2. Make a copy to your Google Drive using File > Make a copy
-3. Define your rules in your sheet
-4. Click "Speckle" menu > "Publish Rules" to get your TSV URL
-5. Create an Automation in Speckle Automate using the Checker function
-6. Paste your TSV URL into the function configuration
-7. Run your automation
+The Checker function allows you to:
 
-## Rule Types
+- Define validation rules in a spreadsheet
+- Configure severity levels for issues
+- Check properties across different types of objects
+- Generate reports of validation results
+- Apply consistent standards across projects
 
-- Property existence
-- Value matching
-- Numeric comparisons
-- Range checks
-- List membership
-- Pattern matching
-- Boolean checks
+## Getting Started
 
-## Severity Levels
+### 1. Prepare Your Rule Spreadsheet
 
-- WARNING: Issues that should be reviewed
-- ERROR: Critical issues requiring attention
+1. Access the [template spreadsheet](https://docs.google.com/spreadsheets/d/1hiPSw23eOaqd27QD_YsXvZg9PWm7_XBx/edit) (
+   make a copy to your drive)
+2. Define your rules using the format explained below
+3. Publish your rules by clicking "File > Download > Tab-separated values (.tsv)"
+4. Upload the TSV file to a hosting service (Google Drive, Dropbox, etc.) and get a public URL
+
+### 2. Create an Automation
+
+1. Go to [Speckle Automate](https://automate.speckle.dev/)
+2. Create a new Automation
+3. Select the Checker function
+4. Configure the function:
+    - Paste your TSV URL
+    - Set minimum severity level to report
+    - Configure other options as needed
+5. Save and run your automation
+
+## Rule Definition Format
+
+Rules are defined in a spreadsheet with the following columns:
+
+| Rule Number | Logic | Property Name | Predicate    | Value     | Message              | Report Severity |
+|-------------|-------|---------------|--------------|-----------|----------------------|-----------------|
+| 1           | WHERE | category      | matches      | Walls     | Wall thickness check | ERROR           |
+| 1           | AND   | Width         | greater than | 200       |                      |                 |
+| 2           | WHERE | category      | matches      | Columns   | Column height check  | WARNING         |
+| 2           | AND   | height        | in range     | 2500,4000 |                      |                 |
+
+### Column Explanation
+
+- **Rule Number**: Groups conditions that belong to the same rule
+- **Logic**: Defines how conditions are combined (WHERE, AND, CHECK)
+- **Property Name**: The object property or parameter to check
+- **Predicate**: Comparison operation (equals, greater than, etc.)
+- **Value**: Reference value for comparison
+- **Message**: Description shown in validation results
+- **Report Severity**: ERROR, WARNING, or INFO
+
+### Supported Predicates
+
+| Predicate        | Description                 | Example                            |
+|------------------|-----------------------------|------------------------------------|
+| exists           | Checks if a property exists | `height` exists                    |
+| equal to         | Exact value match           | `width` equal to `300`             |
+| not equal to     | Value doesn't match         | `material` not equal to `Concrete` |
+| greater than     | Value exceeds threshold     | `height` greater than `3000`       |
+| less than        | Value below threshold       | `thickness` less than `50`         |
+| in range         | Value within bounds         | `elevation` in range `0,10000`     |
+| in list          | Value in allowed set        | `type` in list `W1,W2,W3`          |
+| contains         | Property contains substring | `name` contains `Beam`             |
+| does not contain | Property doesn't contain    | `name` does not contain `temp`     |
+| is true          | Boolean property is true    | `is_structural` is true            |
+| is false         | Boolean property is false   | `is_placeholder` is false          |
+| is like          | Pattern matching            | `name` is like `^BR\d+$`           |
+
+## Rule Logic
+
+- **WHERE**: Filters objects to check (like SELECT WHERE in SQL)
+- **AND**: Additional filter conditions
+- **CHECK**: Final check condition (optional, defaults to last AND)
+
+Objects pass a rule when they match all conditions. Objects that match WHERE/AND filters but fail the CHECK condition
+are reported as issues.
+
+## Working with Object Properties
+
+The Checker understands properties in Speckle objects regardless of schema:
+
+- Direct properties: `category`, `name`, `id`
+- Nested properties: `parameters.WIDTH.value`
+- Revit parameters: Use parameter names like `Mark`, `Width`, `Assembly Code`
 
 ## Example Rules
 
-[Screenshot or example table to be added]
+### Wall Thickness Check
+
+```
+Rule 1: WHERE category equals "Walls" AND width less than "200"
+Message: "Wall too thin - minimum thickness is 200mm"
+Severity: ERROR
+```
+
+### Door Naming Convention
+
+```
+Rule 2: WHERE category equals "Doors" AND name is not like "^D\d{3}$"
+Message: "Door name must follow pattern D followed by 3 digits"
+Severity: WARNING
+```
+
+### Structural Column Height Range
+
+```
+Rule 3: WHERE category equals "Columns" AND is_structural is true AND height not in range "2400,4000"
+Message: "Structural column height outside acceptable range (2400-4000mm)"
+Severity: ERROR
+```
 
 ## Support
 
-For issues or questions, please open a GitHub issue.
\ No newline at end of file
+For issues or questions, please open a GitHub issue or contact your Speckle support representative.
\ No newline at end of file