---
title: "Use JSON with one naming style · Agent Wranglers"
url: https://agentwranglers.se/playbook/api-design/requests-and-responses/json-conventions
updated: 2026-10-20
licence: "All rights reserved"
---

# Use JSON with one naming style

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Required
- Chapter: [Requests and responses](https://agentwranglers.se/playbook/api-design/requests-and-responses)
- Rule: Send and accept JSON with `Content-Type: application/json`, and name every field in one style across the whole API.
- How: Pick `camelCase` or `snake_case` once and write it down in the API guide. Use whole words, not abbreviations. Answer 415 to a body in a type you don't accept. Encode JSON as UTF-8, as RFC 8259 requires.
- Check: A linter such as Spectral, with a casing rule, passes on the OpenAPI file. A request with `Content-Type: text/plain` gets 415.

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers api design playbook: https://agentwranglers.se/playbook/api-design/requests-and-responses/json-conventions`.

- Next: [Send dates as RFC 3339 with a time zone](https://agentwranglers.se/playbook/api-design/requests-and-responses/dates-and-times)
- [Requests and responses](https://agentwranglers.se/playbook/api-design/requests-and-responses)