Optimize for speed - H Platform Docs

The defaults favor accuracy. For interactive apps, these knobs trade some of it for speed. Change one at a time and check the results on your tasks. A run is a session start, then steps. Each step is one model call and one or more tool calls.

Start faster

Knob	Effect	Trade-off
Local mode with a local browser or desktop	No session start wait. Actions run next to the agent, with no network round trip.	Runs on your machine. No web search or subagents.
`lazy: true` (cloud browser)	The session starts before the browser does.	The first browser action waits for it instead.

Shorten each step

Knob	Effect	Trade-off
`model: "holo4-35b-a3b"`	Faster model calls.	Weaker than `holo4-27b` on complex tasks.
`reasoning_effort: "disabled"`	No thinking before each action.	Less planning.
`mode: {"type": "text"}` (browser)	No screenshots to read.	Read-only: the agent cannot click or type.
`settle_s` (default `1.0` browser, `0.5` desktop)	Shorter wait after each action.	The agent may see a page that is still loading.
`mode.width`, `mode.height` (cloud browser), `screenshot_max_width` (desktop)	Smaller screenshots, so fewer image tokens.	Small targets are harder to hit, which can add steps.
Region	Less network latency.	None.
Your own model server	Model calls stay on your network.	You run the GPUs.

A Holo4 screenshot costs about width × height / 1024 input tokens:

Screenshot	Tokens
`800`×`600`	477
`1280`×`800`	1,002
`1200`×`1200` (browser default)	1,446
`1920`×`1080`	2,042
`1920`×`1247` (MacBook Pro 14” at the desktop cap)	2,342

Take fewer steps

Knob	Effect	Trade-off
`start_url`	The agent opens on the right page.	None.
`browser_profile_id`	The session starts signed in.	You maintain the profile.
`instructions`	Naming the exact pages or steps cuts exploration.	None.
Custom tools	One call to your API replaces a multi-step UI flow.	You write and run the tool.
Subagents	Independent subtasks run in parallel.	Each subagent is its own session.

Example

A fast, read-only research agent:

{
  "name": "fast-reader",
  "description": "Answers questions from Wikipedia.",
  "model": "holo4-35b-a3b",
  "reasoning_effort": "disabled",
  "environments": [
    {
      "id": "browser",
      "kind": "web",
      "start_url": "https://en.wikipedia.org/wiki/Python_(programming_language)",
      "settle_s": 0.3,
      "mode": { "type": "text" }
    }
  ]
}

Related: Browser configuration, Agents, Local mode.