arcade.dev agentic web readiness

A+ Manifest validity: 100% (6/6 valid, 0 errors, 19 warnings) · Surface score 70 (coverage 40 + breadth 15 + conformance 15). 9 standards observed across 4 of 9 steps; 6 manifests present (+ security.txt), 0 errors, 19 warnings. Checked 2026-10-25 17:44:47 UTC via www.arcade.dev. This grades the agent-facing files published at arcade.dev, not the organisation's products.

Badge for a README: ![agentic web grade](https://agenticweb.wiki/badge/arcade.dev.svg) · JSON · Markdown · Re-check now

Coverage by step

Manifests

What an agent can call

• MCP endpoint https://www.arcade.dev/mcp (streamable-http) — from /mcp/server-card
• MCP endpoint https://www.arcade.dev/mcp (streamable-http) — from /.well-known/mcp/server-card.json
• API description https://www.arcade.dev/openapi.json (application/json)
• API description https://www.arcade.dev/.well-known/api-catalog (application/linkset+json)
• API description https://www.arcade.dev/openapi.json (application/json)
• API description https://www.arcade.dev/.well-known/api-catalog (application/linkset+json)
• API description https://www.arcade.dev/openapi.json (application/json)
• API description https://docs.arcade.dev/en/references/api (text/html)
• API description https://www.arcade.dev/llms.txt (text/markdown)
• llms.txt: Arcade, 28 links, llms-full.txt present
• robots.txt AI policy: allows GPTBot, ChatGPT-User, ClaudeBot, Claude-User, Google-Extended, PerplexityBot, Perplexity-User, CCBot, Applebot-Extended; unlisted crawlers allowed
• ARD bridge (/.well-known/ard.json): 4/5 valid, 0 legacy, 0 dead/broken

Standards observed

• llms.txt https://arcade.dev/llms.txt
• Content Signals Policy https://arcade.dev/robots.txt
• Agentic Resource Discovery https://arcade.dev/.well-known/ard.json
• AI Catalog well-known file https://arcade.dev/.well-known/ai-catalog.json
• api-catalog: A Well-Known URI and Link Relation to Help Discovery of APIs https://arcade.dev/.well-known/api-catalog
• AI Crawler User-Agent Tokens in robots.txt https://arcade.dev/robots.txt
• Markdown for Agents https://arcade.dev/
• MCP Server Cards (SEP-2127)
• Model Context Protocol

Cheapest next steps

1. AGENTS.md: instructions for coding agents working on or with the site
   Generate starter /AGENTS.md for arcade.dev

   # Arcade for agents
   
   Arcade and what it offers to agents
   
   ## Read the data, not the HTML
   - Index: https://arcade.dev/llms.txt
   - API description: https://arcade.dev/openapi.json
   - Discovery catalog: https://arcade.dev/.well-known/ard.json
   
   ## Calling
   - MCP server (Streamable HTTP): https://arcade.dev/mcp
   - Rate limits and authentication: describe them here
   
   ## Conventions
   - How to cite or attribute content
   - What not to do (no scraping of /account/, no automated sign-ups, etc.)
   
   Contact: security@arcade.dev
   

Agent pre-flight & practical readiness

Preferred mode: mcp (fallback openapi). Call the MCP endpoint at https://www.arcade.dev/mcp first. Do not scrape the HTML when a tool can answer.

Fetch: POST https://www.arcade.dev/mcp POST a JSON-RPC tools/list, or server/discover on the 2026-07-28 revision, before reading HTML.

Practical readability: exa_parsable yes, markdown negotiation yes, render markdown_native, HTML quality high, first content at byte 0, HTML-to-llms.txt token ratio 3.384×.

AI crawler posture: open_to_all · Assistant access: OpenAI allowed, Anthropic allowed, Google allowed, Perplexity allowed, Exa allowed.

Readiness subscores: reach 20/20, readability 30/30, capabilities 29/35, conformance 15/15, total 94/100, grade A+.

How the grade is made

+10 per lifecycle step with a standard observed, counting manifests that validate or that the probe rule for the standard recognises (a valid MCP server card counts for MCP; max 90); +3 per observed standard beyond the first two (max 15); conformance +15 (+10 with one manifest) minus 5 per agent-facing manifest with errors, never below 0 (security.txt is reported, not scored). Lifecycle grade: A+ >= 60, A >= 45, B >= 30, C >= 20, D >= 10. Strict 100-point composite (subscores.total_100 / subscores.grade_100): reach_and_policy (20) + readability (30) + capabilities (35) + conformance (15), where A+ >= 80, A >= 65, B >= 45, C >= 28, D >= 15. Errors are specification violations; warnings are best-practice gaps. Only public paths are fetched, without credentials, so standards that need a login (skipped in the probe) are not counted either way. The same report is the validate_manifest tool on the MCP server.

JSON · Markdown · probe rules