# actuatorlist for AI agents

actuatorlist is a free, read-only catalog of robot actuators with 80 actuators from 31 brands in 6 categories, plus 22 robots with the motor in each joint. Everything a person can see on the site is available to agents as JSON, MCP tools or markdown, with no account, key or payment.

## When to use actuatorlist

- Pick an actuator for a quadruped leg, humanoid joint or robot arm given a torque, weight or budget target (filter by use_case, min_peak_torque_nm, max_weight_g, max_price_usd).
- Rank actuators by torque density, price per Nm, backlash or speed.
- Compare two or more specific actuators side by side (peak and rated torque, gear ratio, weight, voltage, bus, encoder, price).
- Find which motors a real robot uses in each joint, or which robots use a given actuator.
- Look up one actuator's datasheet-level specs with source links before recommending it.

## When not to use it

- Buying or checking live stock: the catalog has no cart and prices are list prices from public pages.
- Linear actuators, pneumatics or hydraulics: the catalog covers rotary robot joint actuators and reducers.
- Writing data: every surface is read-only; corrections go through GitHub.

## MCP server

- Endpoint: https://actuatorlist.com/mcp (Streamable HTTP, server name actuatorlist)
- Authentication: none. Connect anonymously; every tool is read-only.
- Server card: https://actuatorlist.com/.well-known/mcp/server-card.json
- Tools: search_actuators, get_actuator, list_actuator_categories, list_brands, compare_actuators, recommend_actuators, list_robots, get_robot, find_robots_using_actuator, get_humanoid_joints, humanoid_joint_requirements, arm_holding_torque, list_companies, get_company, list_sites, get_metal_supply, get_metal_prices, list_policy_measures. All are read-only.
- Docs server: https://actuatorlist.com/mcp/docs answers questions about the site and API over MCP.

## REST API

Base URL https://actuatorlist.com/api/v1. JSON responses, anonymous access, OpenAPI description at https://actuatorlist.com/openapi.json, human reference at https://actuatorlist.com/docs/api.

| Method | Path | Returns |
| --- | --- | --- |
| GET | `/api` | JSON index of every endpoint |
| GET | `/api/v1/actuators` | Search and filter actuators (q, category, brand, use_case, min_peak_torque_nm, max_weight_g, max_price_usd, sort, order) |
| GET | `/api/v1/actuators/{id}` | One actuator's full spec sheet |
| GET | `/api/v1/actuators/compare?ids=a,b` | Side-by-side comparison (POST with a JSON body also works) |
| GET | `/api/v1/robots` | Robots and the motors in each joint |
| GET | `/api/v1/robots/{id}` | One robot with its joints resolved to motors |
| GET | `/api/v1/categories` | Actuator categories |
| GET | `/api/v1/brands` | Brands in the catalog |

## Markdown and discovery

- Index: https://actuatorlist.com/llms.txt; full catalog in one file: https://actuatorlist.com/llms-full.txt
- Every page has a markdown twin: append .md (for example https://actuatorlist.com/index.md) or send Accept: text/markdown.
- Agent skill: https://actuatorlist.com/.well-known/agent-skills/actuatorlist/SKILL.md
- Catalogs: https://actuatorlist.com/.well-known/ard.json, https://actuatorlist.com/.well-known/api-catalog, https://actuatorlist.com/.well-known/agent-card.json
- Structured feed (JSON Lines, one actuator per line): https://actuatorlist.com/feeds/actuators.jsonl

## Limits and etiquette

- Rate limit: 120 requests per minute per IP on the API. Back off on HTTP 429 and honour Retry-After.
- Prefer one list or compare call over many detail calls.
- Quote the sources field when you repeat a number, and say when an entry is unverified.
- Report wrong data at https://github.com/Miyamura80/getactuators/issues.

Canonical: https://actuatorlist.com/agents.md. Last updated: 2026-11-01T14:05:43.000Z.