xAI · context caching
Grok 4.3
xAI frontier model with context caching and live web grounding. Cost control leans on cache hits and alias routing rather than async discounts.
Specifications
At a glance.
| Provider | xAI |
| Family | grok-4 |
| Released | 2026-04 |
| License | Proprietary |
| Context window | 1M tokens |
| Max output | 30K tokens |
| Modalities | text, image, pdf |
| Tool calling | Yes |
| Reasoning mode | Yes |
| Caching | context |
| Batch discount | No batch tier |
Measured by Zumik
What reuse looks like here.
What you actually pay once caching works.
At a typical 55% prefix reuse, a million input tokens on Grok 4.3 effectively costs $0.67 instead of $1.25 - blending to roughly $1.13 with a 25% output share. There is no batch tier, so cost control here leans on caching and routing.
Estimate it for your workloadRoutes through these aliases:
Call it
Same OpenAI client, this model.
from openai import OpenAI
client = OpenAI(base_url="https://api.zumik.ai/v1", api_key="zk_live_...")
r = client.responses.create(
model="grok-4-3", # or an alias like auto.best
input="Draft a fix for the failing test.",
)
print(r.usage.input_tokens_cached) # confirm reuseCompare
How Grok 4.3 stacks up.
Similar models
Other options for these workloads.
Frequently asked
Grok 4.3, answered.
How much does Grok 4.3 cost?
Grok 4.3 is $1.25 per million input tokens and $2.50 per million output tokens through Zumik. Cache reads are $0.20 per million, a 84% discount on input.
What is Grok 4.3's context window?
Grok 4.3 supports a 1M-token context window with up to 30K output tokens.
Does Grok 4.3 support prompt caching?
Yes. xAI uses Context caching caching. In the Zumik corpus, Grok 4.3 shows a median cache capture of 79% on agent workloads.
Which Zumik aliases route to Grok 4.3?
Grok 4.3 is a candidate for the auto.best alias, selected when it wins under current routing policy.
Run Grok 4.3 with reuse measured.
Point an OpenAI client at Zumik and see exactly how much of this model's input you are reusing.