--- title: "Best Grok Models for Hermes Agent (2026): How to Pick" description: "A developer's guide to choosing a Grok model for Hermes Agent. Pricing, context windows, and which model to reach for — plus setup in Hermes Agent." date: 2026-04-17 updatedDate: 2026-04-17 image: /images/models/provider-xai-hero.jpg keywords: "hermes agent grok, best grok for hermes agent, grok hermes agent setup, grok hermes agent pricing, grok api hermes agent" category: model-guide faq: - question: "Does Grok support all 47 Hermes tools?" answer: "Yes, all models in the Grok family listed here support native function calling, which Hermes uses to interface with its built-in toolset and external MCP servers." - question: "Which model is best for a Telegram-based agent?" answer: "Grok 4.1 Fast is ideal because its 2M context window can store months of chat history, allowing the agent to maintain persistent context without needing a separate database for long-term memory." - question: "Is the 2M context window real?" answer: "Yes, but performance in 'finding the needle' can degrade as you fill it. For Hermes, keep your most important tool definitions and system instructions at the top of the prompt." --- Current as of April 2026. Grok models are the current price-to-performance leaders for high-volume autonomous agents. For Hermes users running persistent workflows across Telegram or Slack, the massive context windows and aggressive pricing of the xAI family allow for extensive tool-use history and cross-session memory without the massive overhead of other providers. ## The quick answer | Model | Input / Output | Context | Best For | |---|---|---|---| | **Grok 4.1 Fast** | $0.20 / $0.50 | 2M | The Context King for Long-Running Agents | | **Grok 4 Fast** | $0.20 / $0.50 | 2M | The Redundant Baseline | | **Grok Code Fast** | $0.20 / $1.50 | 256K | The High-Volume Output Specialist | | **Grok 3 Mini** | $0.30 / $0.50 | 131K | The Reliable Tool-Call Specialist | | **Grok 3 Mini Fast** | $0.60 / $4.00 | 131K | The Reliable Tool-Call Specialist | | **Grok 2** | $2.00 / $10 | 131K | The Proven Legacy Workhorse | | **Grok 2 Vision** | $2.00 / $10 | 33K | The Proven Legacy Workhorse | | **Grok 4.20** | $2.00 / $6.00 | 2M | The Heavy-Duty Reasoning Engine | Start with **Grok 4.1 Fast** unless you have a specific reason to pick another. It offers a massive 2M token context window at a rock-bottom price of $0.20 per million input tokens. This is the most economical way to keep months of agent interaction history in-context for persistent Hermes sessions. ## Grok 4.1 Fast — The Context King for Long-Running Agents This is the best choice for Hermes agents that need to track long-running conversations across multiple platforms. With a 2M token context window and pricing at $0.2/M input and $0.5/M output, it allows the agent to ingest massive amounts of data from tools and MCP servers without hitting memory limits or breaking the bank. ## Grok 4 Fast — The Redundant Baseline Grok 4 Fast is nearly identical to 4.1 Fast in both pricing ($0.2/$0.5) and context (2M). Prefer 4.1 Fast for its newer optimizations; use this model only as a fallback if you encounter specific version-related regressions in tool-calling reliability or API availability. ## Grok Code Fast — The High-Volume Output Specialist Despite the name, this model is valuable for Hermes agents that need to generate massive text outputs, like long-form reports or extensive log summaries, thanks to its 256K max output cap. While output is more expensive at $1.5/M, the 256K context and reasoning capabilities handle complex tool chains well. ## Grok 3 Mini — The Reliable Tool-Call Specialist At $0.3/M input and $0.5/M output, this is slightly more expensive on the input side than the 4-series Fast models but offers highly reliable function calling for Hermes' 47+ tools. The 131K context is more than enough for daily agent tasks that don't require massive document ingestion. ## Grok 3 Mini Fast — The Reliable Tool-Call Specialist At $0.3/M input and $0.5/M output, this is slightly more expensive on the input side than the 4-series Fast models but offers highly reliable function calling for Hermes' 47+ tools. The 131K context is more than enough for daily agent tasks that don't require massive document ingestion. ## Grok 2 — The Proven Legacy Workhorse Grok 2 is significantly more expensive at $2/M input and $10/M output. Its only use case in Hermes is for users who have highly specific, legacy system prompts tuned to its specific logic patterns; otherwise, the 4-series offers more context for a fraction of the cost. ## Grok 2 Vision — The Proven Legacy Workhorse Grok 2 is significantly more expensive at $2/M input and $10/M output. Its only use case in Hermes is for users who have highly specific, legacy system prompts tuned to its specific logic patterns; otherwise, the 4-series offers more context for a fraction of the cost. ## Grok 4.20 — The Heavy-Duty Reasoning Engine When 'Fast' models fail to navigate complex multi-step reasoning in Hermes, 4.20 is the solution. It costs $2/M input and $6/M output but maintains the 2M context window, making it the most powerful option for agents that need to synthesize data from multiple MCP tools simultaneously. ## Setup in Hermes Agent To integrate Grok with Hermes, run `hermes model` and select 'Custom endpoint'. Use `https://api.x.ai/v1` as the base URL and enter your xAI API key. Ensure you specify the exact model identifier, such as `xai/grok-4.1-fast`, to match the billing tier you want. #### Running through haimaker.ai Rather than standing up a per-provider account, you can point Hermes at haimaker.ai and get access to Grok alongside every other frontier model through one API key: - **Base URL:** `https://api.haimaker.ai/v1` - **Model:** `xai/grok-4.1-fast` #### Direct provider setup Hermes makes custom endpoints easy. Run: ```bash hermes model ``` Choose **Custom endpoint** from the menu. Enter the base URL and model identifier when prompted: - **Base URL:** `https://api.x.ai/v1` - **Model:** `xai/grok-4.1-fast` Hermes stores the selection and uses it for all subsequent agent runs. You can also set `HERMES_STREAM_READ_TIMEOUT` and related env vars if you're hitting slow providers. ## Bottom line For the majority of Hermes Agent deployments, Grok 4.1 Fast provides the best balance of a massive 2M context window and extremely low $0.2/M input pricing, making it the top choice for autonomous, multi-platform agents. RUN GROK IN HERMES WITH HAIMAKER --- *See our [Hermes local-LLM setup guide](https://hermes-agent.nousresearch.com/docs/guides/local-llm-on-mac).*