# Platform and Documentation Version Compatibility

## In a nutshell:

- The INJECT platform comes in different versions. If you are looking for the platform changelog, go
    here: [platform changelog](../changelog.md).
- Each platform version has a matching definition versions. If you are looking for the definitions
    changelog, go here: [definition changelog](architecture/definitions/CHANGELOG.md).
- Check the table below to find which definition version you should use.

---

| Definition Version | Platform Version | Codename |
| ------------------ | ---------------- | -------- |
| 0.23.3             | 4.0.X            | Dux      |
| 0.18.1             | 3.0.X            | Citadel  |
| 0.12.1             | 2.0.X            | Bastion  |
| 0.8.0              | 1.0.X            | Aegis    |

[Definition upgrade Guide](architecture/definitions/upgrade.md){ .md-button }
