Introducing GPT-5.3 Codex on Majestix AI
April 22, 2026by Majestix AImodelsopenaiflagshipcodingagentic
Why GPT-5.3 Codex matters
GPT-5.3 Codex is a flagship model in the Majestix lineup built for coding, agentic, debugging workloads, with 400K context and $2.10 / $14.70 per 1M tokens. This card is written for Majestix users, so the focus is on where the model fits inside our product rather than how to self-host it.
What it is good at
- Coding
- Agentic
- Debugging
- Tool Use
Majestix platform snapshot
| Metric | Value |
|---|---|
| Provider | OpenAI |
| Category | Flagship |
| Access | Guru+ |
| Context window | 400K |
| Max output | 32K |
| Pricing | $2.10 input / $14.70 output per 1M tokens |
Benchmarks and operating signals
| Signal | Value | Source |
|---|---|---|
| Context Window | 400K | platform limit |
| Max Output | 32K | platform limit |
| Output Price | $14.70 / 1M | Majestix pricing |
Where Majestix already uses it
- No public swarm templates currently pin this model. It is still available in the platform catalog.
When to choose it
GPT-5.3 Codex is the right pick when you want coding and agentic without manually spelunking through vendor docs. On Majestix, you can compare it directly against the rest of the lineup on pricing, context, and swarm fit.