A jig is a type of custom-made tool used to control the location or motion of parts or other tools. A jig's primary purpose is to provide repeatability, accuracy, and interchangeability in the manufacturing of products.

Jonathan's Implementation Guidance — structured, opinionated documentation for HTTP API service design and development.

JIGs are concise, numbered documents that capture implementation decisions, patterns, and standards. Inspired by Google's API Improvement Proposals (AIPs), JIGs are tailored for HTTP API services rather than gRPC.

Each JIG follows a consistent format with guidance, examples, anti-patterns, and rationale, using RFC 2119 keywords to clearly convey requirements.

JIGs are written to be useful for both:

• Human developers — as readable reference documentation for design decisions
• AI agents — as structured, machine-parsable guidance that can be applied autonomously (e.g. via MCP servers)

jigs/
├── template.md          # Standard template for new JIGs
├── general/             # Meta-JIGs and cross-cutting guidance
│   ├── 0001.md          # JIG Purpose and Guidelines
│   ├── 0002.md          # JIG Numbering
│   └── 0008.md          # JIG Style and Guidance
└── api-design/          # API design patterns
    ├── 0122.md          # Resource Names
    ├── 0123.md          # Resource Types
    ├── 0124.md          # Listing Resources
    ├── 0126.md          # Custom Methods
    ├── 0129.md          # Error Handling Basics
    ├── 0130.md          # HTTP Errors
    ├── 0131.md          # Common Custom Methods
    ├── 0132.md          # Partial Update
    ├── 0133.md          # Deletion
    ├── 0134.md          # Undelete Operations
    └── 0135.md          # Batch Operations

1. Copy jigs/template.md
2. Assign the next available number in the appropriate range (see JIG-0002)
3. Follow the style rules in JIG-0008
4. Place the file in the matching category directory