xAI · Balanced
Grok Build 0.1
Grok Build 0.1 is SpaceXAI's fast coding model trained specifically for agentic software engineering workflows. It supports text and image inputs with text output, and is optimized for interactive coding agents, tool use, and multi-step development tasks. Currently in early access. Content policy rejections can still be charged: SpaceXAI may pass through a $0.05 moderation-failure fee, or a $0.055 usage-guidelines violation fee, depending on which rejection upstream returns.
- Reasoning
- Tools
- Vision
- Structured output
- Input
- Text, Images
- Output
- Text
- Discovery tier
- Balanced
Pricing
USD per 1M tokens- Input
- $1.00
- Output
- $2.00
- Cache read
- $0.20
Reference prices as published by the model provider. API example
Specifications
- Context window
- 256K
- Max output
- —
- Average output (7 days)
- 3K tokens
- Longer than 96% of 473 models
Side by side
Grok Build 0.1 compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| Grok Build 0.1xAIThis model | Grok 4.20xAIRemove | |
|---|---|---|
| Provider | xAI | xAI |
| Discovery tier | Balanced | Balanced |
| Added | May 20, 2026 | Mar 31, 2026 |
| Limits | ||
| Context window | 256K | 2MBest |
| Max output | — | 131.07K |
| Average output | 3K tokens | 679 tokens |
| Pricing, USD per 1M tokens | ||
| Input | $1.00Best | $1.25 |
| Output | $2.00Best | $2.50 |
| Cache read | $0.20 | $0.20 |
| Performance | ||
| Throughput | — | 327.6 tok/s |
| Time to first token | — | 1.8 s |
| Request success (24h) | — | 99.8% |
| Benchmark indexes | ||
| Intelligence Index | 27.2Best | 25.7 |
| Coding Index | 51.5 | — |
| Capabilities | ||
| Reasoning | Yes | Yes |
| Tools | Yes | Yes |
| Vision | Yes | Yes |
| Structured output | Yes | Yes |
| Reasoning effort | — | — |
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
- Grok Build 0.1
- Grok 4.20
Intelligence Index
- Grok Build 0.127.2
- Grok 4.2025.7
Grok Build 0.1: Better than 69% of 326 scored models
Indexes
Coding Index
Composite of the coding evaluations
- Grok Build 0.1: 51.5
- Grok 4.20: —
Agentic work
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- Grok Build 0.1: 1,065 Elo
- Grok 4.20: —
Document reasoning
AA-LCRv1.1
Reasoning across long documents
- Grok Build 0.1: 74.7%Top
- Grok 4.20: 69.0%
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Grok Build 0.1: 38.3%Top
- Grok 4.20: 34.5%
GPQA Diamond
Graduate-level science questions
- Grok Build 0.1: 89.5%
- Grok 4.20: 91.1%Top
IFBench
Following precise output instructions
- Grok Build 0.1: —
- Grok 4.20: 81.2%
Legacy evaluations
Terminal-Bench Hard
Earlier terminal task suite
- Grok Build 0.1: —
- Grok 4.20: 37.9%
τ²-Bench Telecom
Tool use in a customer-support simulation
- Grok Build 0.1: —
- Grok 4.20: 93.0%
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Grok Build 0.1: 74.7%Top
- Grok 4.20: 69.0%
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- Grok Build 0.1
- Grok 4.20
| Leaderboard | Grok Build 0.1 | Grok 4.20 |
|---|---|---|
| Vision Style Control · Entity Recognition | Not in top 20 | #7 · 1238.1 |
Ranks among Noumen catalog models on LMArena leaderboards. Only top-20 placements are listed.LMArena
- Grok Build 0.1
- Grok 4.20
| Leaderboard | Grok Build 0.1 | Grok 4.20 |
|---|---|---|
| FrontierMath v2 (Tiers 1–3) | Not in top 20 | #14 · 44.9% |
| GPQA Diamond | Not in top 20 | #12 · 89.3% |
Ranks among Noumen catalog models on Epoch AI leaderboards. Only top-20 placements are listed.Epoch AI
- Grok Build 0.1
- Grok 4.20
| Leaderboard | Grok Build 0.1 | Grok 4.20 |
|---|---|---|
| ARC-AGI-3 (Default harness) | Not in top 20 | #20 · 0.1% |
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
Developers
Use it through the API
Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.
curl https://www.noumen.xyz/api/v1/chat/completions \
-H "Authorization: Bearer $NOUMEN_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "x-ai/grok-build-0.1",
"messages": [{ "role": "user", "content": "Explain this stack trace." }]
}'import os
from openai import OpenAI
client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
model="x-ai/grok-build-0.1",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)xAI
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