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Grok 4.20 (Reasoning / Non-reasoning / Multi-Agent)

xAIlegacyreasoning-llmGrok 4

Snapshot ids dated 0309. xAI docs list 1M context; OpenRouter lists 2M. Superseded by Grok 4.5-4.7; logprobs unsupported.

Context window
1,000,000 tokens
Input
text, image
Output
text
License
proprietary
Pricing
input: $1.25 · cached input: $0.2 · output: $2.5 · input over 200k: $2.5 · output over 200k: $5 (per 1M tokens (USD)) source
Verified
2026-09-29

How to call it

ProviderModel idEndpoint / URLDocs
xAI APIgrok-4.20-0309-reasoninghttps://api.x.ai/v1/chat/completionsdocs
xAI API (non-reasoning)grok-4.20-0309-non-reasoninghttps://api.x.ai/v1/chat/completions—
xAI API (multi-agent)grok-4.20-multi-agent-0309—docs
OpenRouterx-ai/grok-4.20openrouter.ai/x-ai/grok-4.20—
OpenRouter (multi-agent)x-ai/grok-4.20-multi-agentopenrouter.ai/x-ai/grok-4.20-multi-agent—

Notable capabilities (2)

Previous-generation Grok, notable for its multi-agent variant for deep research.

curl https://api.x.ai/v1/chat/completions -H "Authorization: Bearer $XAI_API_KEY" -H "Content-Type: application/json" \
 -d '{"model":"grok-4.20-0309-reasoning","messages":[{"role":"user","content":"Hello"}]}'

Sources: https://docs.x.ai/docs/models , https://docs.x.ai/developers/model-capabilities/text/multi-agent

Other xAI models

Grok 4.7 · Grok Voice Transcribe 2.0 · Grok Imagine Image 2.0 · Grok Voice Think Fast 2.0 · Grok Imagine Video 1.5 · Grok Build 0.1 · Grok Text to Speech (Grok TTS API) · Grok 4.3