# Grok 4.5

> **TL;DR.** Grok 4.

- **Category:** AI / Frontier Models / SpaceXAI
- **Stage:** nascent
- **Age:** 1 days
- **Origin date:** 2026-07-08
- **First detected:** 2026-07-09
- **Canonical URL:** https://earlyterms.com/term/grok-4-5
- **Sources:** 6 primary URLs

## Definition

Grok 4.5 is SpaceXAI's flagship mixture-of-experts model for coding, agentic tasks, and knowledge work, built on a 1.5T-parameter foundation and trained with trillions of tokens of real developer interaction data from [Cursor](https://cursor.com/blog/grok-4-5). Elon Musk called it "an Opus-class model, but faster, more token-efficient and lower cost."

SpaceXAI and Cursor jointly launched it on [July 8, 2026](https://x.ai/news/grok-4-5) at $2/M input and $6/M output tokens, live in Grok Build, Cursor, and the SpaceXAI console — the first model shipped since SpaceX's June 16, 2026 announcement of its $60B acquisition of Cursor-maker Anysphere and the wider xAI-to-SpaceXAI corporate rebrand.

## Example

Cursor's own CursorBench and independent trackers show Grok 4.5 beating GPT-5.5 and Claude Opus 4.8 on Terminal-Bench 2.1 and DeepSWE 1.0, using roughly 4.2x fewer output tokens than Opus 4.8 on SWE-Bench Pro, though it trails Anthropic's Claude Fable 5 on every benchmark shown.

## Analogy

Think of it as the first car built on a shared assembly line after two rival factories merged — same badge, combined parts bin.

## Why it's emerging now

SpaceXAI (formerly xAI) shipped Grok 4.5 on July 8, 2026 as its first model trained on Cursor's codebase data since SpaceX's $60B Anysphere acquisition closed the loop between the space company, Musk's AI lab, and the coding tool 50,000+ enterprises use daily.

## Related terms

- *related:* grok-build
- *competitor:* claude-fable-5
- *competitor:* gpt-5-5
- *competitor:* claude-opus-4-8
- *competitor:* glm-5-2
- *related:* cursor-cli
- *related:* deepswe
- *related:* coding-plan
- *parent:* agentic-coding
- *competitor:* Composer 2.5

## Sources

1. [SpaceXAI — Introducing Grok 4.5](https://x.ai/news/grok-4-5)
2. [Cursor — Introducing Grok 4.5](https://cursor.com/blog/grok-4-5)
3. [MarkTechPost coverage](https://www.marktechpost.com/2026/07/08/spacexai-releases-grok-4-5/)
4. [Axios: SpaceXAI's new model](https://www.axios.com/2026/07/08/spacexai-grok-new-model)
5. [Hacker News discussion](https://news.ycombinator.com/item?id=48835111)
6. [CNBC: SpaceX to acquire Cursor for $60 billion](https://www.cnbc.com/2026/06/16/spacex-spcx-cursor-acquisition-ipo.html)

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_Generated by EarlyTerms · https://earlyterms.com/term/grok-4-5_