Horton agent

The built-in assistant registered by the Electric Agents dev server. Horton can chat conversationally, search the web, read and edit files, run shell commands, and dispatch workers for isolated subtasks.

Source: packages/agents/src/agents/horton.ts

Try it

With the dev server running (npx electric-ax agents quickstart):

npx electric-ax agents spawn /horton/my-horton
npx electric-ax agents send /horton/my-horton 'What's in this directory?'
npx electric-ax agents observe /horton/my-horton

Tools

Horton is configured with ctx.electricTools plus the base Horton tool set:

Tool	Purpose
bash	Run shell commands in the working directory.
read	Read a file.
write	Create or overwrite a file.
edit	Targeted string replacement.
web_search	Web search via the configured search provider.
fetch_url	Fetch a URL and return it as markdown.
spawn_worker	Dispatch a subagent for an isolated subtask.
fork	Branch a session at its latest completed response.
observe_pg_sync	Observe an Electric Postgres shape and wake on changes.
unobserve_pg_sync	Remove an existing pg-sync observation.
send	Send a message to another entity.
set_title	Rename the current chat session title.

web_search uses the search provider configured by the built-in runtime; Brave search requires BRAVE_SEARCH_API_KEY.

When docs support or skills are available, Horton also adds the docs search tool and skill tools during bootstrap. Built-in runtimes also provide ctx.electricTools, including schedule tools and webhook-source tools when configured.

Title generation

After the first agent run completes, Horton calls generateTitle() using the configured low-cost model to summarise the user's first message into a 3-5 word session title and stores it via ctx.setTag('title', title). Failures are logged and ignored — the entity continues without a title.

Details

Property	Value
Type name	horton
Model	HORTON_MODEL (claude-sonnet-4-6 by default)
Title model	Configured low-cost model
Tools	ctx.electricTools + base Horton tool set, plus docs/skill tools when configured
Working directory	Passed at bootstrap (defaults to process.cwd())
Title generation	Yes, after the first run if no title tag exists

Extending Horton

The system prompt and tool factory are exported so you can build your own variants:

import {
  HORTON_MODEL,
  buildHortonSystemPrompt,
  createHortonTools,
} from "@electric-ax/agents"

registry.define("my-assistant", {
  description: "Horton with an extra custom tool",
  async handler(ctx) {
    ctx.useAgent({
      systemPrompt: buildHortonSystemPrompt(process.cwd()),
      model: HORTON_MODEL,
      tools: [
        ...ctx.electricTools,
        ...createHortonTools(ctx.sandbox, ctx),
        myCustomTool,
      ],
    })
    await ctx.agent.run()
  },
})

Related

• Worker — the subagent type Horton dispatches via spawn_worker.