@agentskit/tools

Give your agents real-world capabilities without writing a single integration.

Tags: ai · agents · llm · agentskit · ai-agents · function-calling · tool-use · mcp · web-search · filesystem

Why tools

• Save days of integration work — web search, filesystem read/write, shell execution, and directory listing are ready to drop in; no wiring required
• Safe by default — filesystem tools are sandboxed to a basePath, shell commands require an explicit allowlist, so agents can't escape their boundaries
• Composable with any runtime — tools are just objects with a schema; they work with @agentskit/runtime, useChat, or any custom ReAct loop
• Extend without friction — author custom tools with @agentskit/templates and register them the same way as built-ins

Install

npm install @agentskit/tools

Quick example

import { createRuntime } from '@agentskit/runtime'
import { openai } from '@agentskit/adapters'
import { webSearch, filesystem, shell } from '@agentskit/tools'

const runtime = createRuntime({
  adapter: openai({ apiKey: process.env.OPENAI_API_KEY, model: 'gpt-4o' }),
  tools: [
    webSearch(),
    ...filesystem({ basePath: './workspace' }),
    shell({ timeout: 10_000, allowed: ['ls', 'cat', 'grep'] }),
  ],
})

const result = await runtime.run('Find the README and summarize it')
console.log(result.content)

With useChat (browser)

Tools are plain ToolDefinition values — register them in useChat the same way as in createRuntime.

Authoring tools with defineZodTool

If you use Zod, @agentskit/tools ships defineZodTool — a factory that:

• Types execute args from a Zod schema (full TypeScript inference)
• Validates args at runtime via schema.parse before calling your function
• Converts the Zod schema to JSON Schema for the adapter via a user-supplied toJsonSchema callback

Zod and zod-to-json-schema are not bundled — install them as peer dependencies.

npm install zod zod-to-json-schema

import { z } from 'zod'
import { zodToJsonSchema } from 'zod-to-json-schema'
import { defineZodTool } from '@agentskit/tools'
import type { JSONSchema7 } from 'json-schema'

const lookupUser = defineZodTool({
  name: 'lookup_user',
  description: 'Look up a user by ID.',
  schema: z.object({
    userId: z.string().uuid(),
    includeProfile: z.boolean().optional(),
  }),
  toJsonSchema: (s) => zodToJsonSchema(s) as JSONSchema7,
  async execute(args) {
    // args.userId         → string  (UUID-validated by Zod at runtime)
    // args.includeProfile → boolean | undefined
    return await db.users.findById(args.userId, { profile: args.includeProfile })
  },
})

For tools without Zod, use defineTool from @agentskit/core with a JSON Schema as const.

Features

Built-ins (6)

• webSearch() — live web search with pluggable providers (Tavily, Brave, SerpAPI, custom).
• fetchUrl() — safe HTTP GET with JSON / text handling, size cap, boilerplate stripping.
• filesystem({ basePath }) — sandboxed read, write, list, delete, stat, exists.
• shell({ allowed }) — shell execution with command allow-list + timeout.
• sqliteQueryTool({ path }) — read-only SQL against a local SQLite file. Optional peer dep on better-sqlite3. Note: never feed unvalidated user prompts straight into the sql field — wrap with input filtering or use parameterized helpers if exposing it to untrusted input.
• slackTool({ webhookUrl }) — post to a Slack Incoming Webhook. For Bearer-token features (search, channel listing), use the slack() integration.

Integrations (20+)

github, linear, slack, notion, discord, gmail, googleCalendar, stripe, postgres, s3, firecrawl, reader, documentParsers (PDF / DOCX / XLSX), openaiImages, elevenlabs, whisper, deepgram, maps, weather, coingecko, browserAgent (Puppeteer). Each integration exports granular sub-tools (e.g. githubCreateIssue, stripeCreatePaymentIntent) alongside the bundled set.

Authoring + composition

• defineZodTool — Zod-based factory with runtime validation + type inference.
• composeTool — chain N tools into one macro tool (each step receives previous output).
• wrapToolWithSelfDebug — LLM-corrected retries on schema-mismatch or execution failure.
• createMandatorySandbox — policy wrapper: allow / deny / requireSandbox / validators.

MCP bridge

• createMcpClient + toolsFromMcpClient — consume any MCP server's tools.
• createMcpServer — publish AgentsKit tools to any MCP host.
• Stdio + HTTP/SSE + in-memory transports.

All tools honor the ToolDefinition contract (ADR 0002) — parallel tool calling works with any adapter, @agentskit/runtime, useChat, or a custom loop.

Subpaths

Ecosystem

Contributors

License

MIT — see LICENSE.

Docs

Full documentation · GitHub