Step 1: Defining Errors

Error Code Naming Convention

All error codes follow a standardized format for consistency and searchability:

Error-{PRODUCT}-{NUMBER}

Examples:
Error-FlowStudio-100090
Error-AppStudio-200001
Error-ProcessEngine-150025

Components Explained

Assigning Error Numbers

Each product has 100,000 error codes available. Error number ranges are organized by product and feature area:

Product Allocation (100,000 codes each)

FlowStudio:        100000-199999 (100,000 codes)
AppStudio:         200000-299999 (100,000 codes)
AtlasForms:        300000-399999 (100,000 codes)
Octopus:           400000-499999 (100,000 codes)
Passport:          500000-599999 (100,000 codes)
WorkDesk:          600000-699999 (100,000 codes)
BizFirstObserve:   700000-799999 (100,000 codes)
EdgeStream:        800000-899999 (100,000 codes)
Custom/Integration:900000-999999 (100,000 codes)

Feature Area Organization (within your product range)

Within your product's 100,000 codes, organize by feature area using the second digit:

FlowStudio Examples:
  10x000-10x999 → Workflow execution (Feature: Execution)
  11x000-11x999 → Node system (Feature: Nodes)
  12x000-12x999 → Canvas/UI (Feature: Canvas)
  13x000-13x999 → Data binding (Feature: DataBinding)
  14x000-14x999 → Permissions (Feature: Security)
  15x000-15x999 → Store/State (Feature: Store)
  16x000-16x999 → Integration/API (Feature: Integration)
  17x000-17x999 → Observability (Feature: Observability)
  18x000-18x999 → Configuration (Feature: Config)
  19x000-19x999 → Reserved (Feature: Reserved)

  Pattern: {ProductStart}{FeatureDigit}{SubCategory}
  Example: 1 (FlowStudio) 0 (Execution) 0090 = 100090

Sub-Category Organization (1000 codes per feature)

Each feature area has 1000 codes available:

Within each feature's 1000 codes:
  XX0000-XX0099 → Validation/Input errors
  XX0100-XX0199 → Execution/Runtime errors
  XX0200-XX0299 → Data/Binding errors
  XX0300-XX0399 → State/Store errors
  XX0400-XX0499 → Permission/Security errors
  XX0500-XX0599 → Configuration errors
  XX0600-XX0699 → Integration/API errors
  XX0700-XX0799 → UI/Presentation errors
  XX0800-XX0899 → Resource/Performance errors
  XX0900-XX0999 → Miscellaneous/Other errors

Developers are responsible for choosing unique numbers within their product's namespace. Plan your feature areas to support growth (e.g., reserve features 10-19 for execution if you expect many codes).

Creating Error in Code

When throwing errors in your application, include the error code in your exception:

C# Example

throw new ApplicationException(
  "Error-FlowStudio-100090: Cannot execute node with invalid input"
);

JavaScript/TypeScript Example

throw new Error(
  "Error-FlowStudio-100090: Cannot execute node with invalid input"
);

Best Practices

• Always include the error code at the start of the message
• Make the message descriptive and actionable
• Include context (parameter names, values, constraints)
• Never include sensitive data (passwords, API keys, tokens)

Error Categories

When defining errors, classify them by category:

Picking a New Error Code (Non-Existing)

When you need to create a new error code that doesn't exist yet, follow this process to pick from your product's 100,000 available codes:

Step 1: Determine Your Product (100,000 codes)

First, identify which product owns this error and its base range:

Step 2: Choose Feature Area (1000 codes per feature)

Pick a feature area within your product using the second digit:

FlowStudio (100000-199999) example:

  10x000-10x999 → Execution (10 available: 100000-109999)
  11x000-11x999 → Nodes (10 available: 110000-119999)
  12x000-12x999 → Canvas (10 available: 120000-129999)
  13x000-13x999 → DataBinding (10 available: 130000-139999)
  14x000-14x999 → Security (10 available: 140000-149999)
  15x000-15x999 → Store (10 available: 150000-159999)
  16x000-16x999 → Integration (10 available: 160000-169999)
  17x000-17x999 → Observability (10 available: 170000-179999)
  18x000-18x999 → Config (10 available: 180000-189999)
  19x000-19x999 → Reserved (10 available: 190000-199999)

Pattern: {Base} + {Feature Digit} x1000 + {SubCategory}

Step 3: Identify Sub-Category (within 1000-code feature block)

Each feature block has 1000 codes organized by error type:

Step 4: Find Next Available Number

Method A: Check ErrorCodes Index

1. Open ErrorManagement/ErrorCodes/Index.html
2. Find your product section
3. See "Next Available" number (updated automatically)

Method B: Search in Code

# Find highest number in your product
grep -r "Error-FlowStudio-" src/ packages/ | \
  grep -o "[0-9]\{6\}" | sort -n | tail -1

# Example output: 100090
# Your next code: 100091

Method C: List Documentation Files

# List all existing error codes for your product
ls ErrorManagement/ErrorCodes/Error-FlowStudio-*.html | \
  sort -V | tail -5

# Shows last 5 codes, pick the next sequential number

Step 5: Validate Uniqueness

# Check if this code already exists
grep -r "Error-FlowStudio-100091" .
# Should return: No matches

# Check documentation
ls ErrorManagement/ErrorCodes/Error-FlowStudio-100091.html
# Should return: No such file

Step 6: Reserve and Document

Once you've picked your number:

1. Add it to your code error messages/logs
2. Create documentation page: Error-{PRODUCT}-{NUMBER}.html
3. Update ErrorCodes/Index.html with the new error card
4. Commit code + documentation together

Reserving Error Codes

To avoid conflicts:

1. Check the ErrorCodes/ directory for existing codes in your range
2. Follow the "Picking a New Error Code" process above
3. Document the range in your service's README or developer guide
4. Commit your error code documentation at the same time as your code change

Common Mistakes

Next Steps

Once you've defined your error code, proceed to Step 2: Documentation to create the error reference page.