Grok 4.20 Multi Agent Beta 0309
SpaceXSI
Key facts · verified Oct 29, 2026
Grok 4.20 Multi Agent Beta 0309 is a SpaceXSI model. Its API price is $1.25 per million input tokens and $2.50 per million output tokens (under 200k prompt tokens; $2.50 / $5.00 at 200k and above). Its context window is 1M tokens. It ranks #48 on LMArena's text leaderboard (Elo 1471, read 1 Nov 2026). Source: docs.x.ai.
Grok 4.20 Multi Agent Beta 0309 is the beta checkpoint of SpaceXSI's Grok 4.20 multi-agent model; xAI's API lists the model as grok-4.20-multi-agent-0309 with a 1M-token context window. xAI prices it at $1.25 per million input tokens and $2.50 per million output tokens for prompts under 200k tokens, with higher rates at 200k and above. On LMArena's text leaderboard: 1471 Elo (rank 48).
Pricing & specs checkedSource: vendor documentation · checked Oct 29, 2026LMArena: 1471 Elo (rank 48) · source · retrieved Nov 1, 2026
Full Specifications
$1.25 / $2.50 per million tokens | |
|---|---|
| Identity | |
| Developer | SpaceXSI |
| Status | Beta checkpoint; served on the xAI API as grok-4.20-multi-agent-0309. |
| Licence | Proprietary |
| Self-hostable | No |
| Cost | |
| Blended $/1M tokensinput × 0.75 + output × 0.25 | $1.563 / 1M tokens |
| Input price | $1.250 / 1M tokens |
| Output price | $2.500 / 1M tokens |
| Capacity | |
| Context window | 1M tokens |
| Measured quality | |
| LMArena Elo | 1471 (checked Nov 2026) |
| LMArena rank | Rank 48 |
| Elo per dollarLMArena Elo ÷ blended $/1M tokens | 941 |