# Agentic Atlas > Field-tested patterns for designing agentic systems — skills, > subagents, plugins, and multi-agent workflows. One atlas, published > for people to read and for agents to consult directly. Agentic Atlas publishes one sealed Release of a curated pattern corpus. Every surface below reads that same Release, and every response names it in the `X-Catalog-Revision` header, so a caller can always tell whether two answers describe the same Atlas. ## When to use this Reach for the Atlas while an agentic design decision is still open — before it is settled, not after: - Choosing a decomposition — how an agentic system divides into skills, subagents, or tools. - Drawing dispatch boundaries — what gets its own agent, and what does not. - Budgeting context, and shaping what a subagent carries in or returns out. - Placing verification seams, so a wrong answer is caught rather than propagated. - Deciding the persistence or configuration shape an agentic workflow needs. - Reviewing or restructuring an existing skill, plugin, or multi-agent workflow. Do not reach for it for: - Executing a skill you already have — the Atlas informs design, it does not run workflows. - Writing ordinary application code. - Any task that merely mentions agents without turning on a design decision. ## How an agent should call this - [MCP endpoint](https://agentic-atlas.dev/mcp/): The preferred surface. Stateless Streamable HTTP, no authentication, nothing to install. Exactly 8 tools: `atlas_orient`, `atlas_cards`, `atlas_read`, `atlas_links`, `atlas_provenance`, `atlas_navigate`, `atlas_define`, `atlas_decisions`. - [Consultation contract](https://agentic-atlas.dev/consult.md): The rules that govern every call — direct address, atomic batching, declared recovery, coherence markers. Written to be copied into a system prompt verbatim. - [Claude Code plugin](https://github.com/aj604/agentic-atlas-plugin): Registers the hosted transport and a librarian subagent. For scripted access from anywhere else, call the MCP endpoint or the JSON API directly — there is no separate CLI to install. ## HTTP API - [OpenAPI description](https://agentic-atlas.dev/openapi.json): Every JSON operation, typed. Read-only, unauthenticated, no key required. - [API reference](https://agentic-atlas.dev/docs): The same description, browsable. - [Machine-readable index](https://agentic-atlas.dev/api/tree): The canonical traversal of every published Node. ## Pages - [Why the Atlas exists](https://agentic-atlas.dev/why): What is published, what is deliberately not, and on what evidence. - [Connect an agent](https://agentic-atlas.dev/connect): The transport, the tool grammar, and a worked first call. - [Atlas map](https://agentic-atlas.dev/atlas): The survey — every plate and how they relate. - [Glossary](https://agentic-atlas.dev/glossary): The admitted vocabulary. - [Decision records](https://agentic-atlas.dev/decisions): Why the corpus is shaped the way it is. ## Content negotiation Every page listed under **Pages** above answers `Accept: text/markdown` with a Markdown rendering of the same document, and names `Accept` in `Vary`. Prefer it to scraping the HTML. The same document is addressable directly, by appending `.md` to the page's path: `/why.md`, `/nodes/.md`, `/index.md` for the front door. Identical bytes, no header needed. Every page names its own `.md` address in a `rel="alternate"` link and in a `Link` response header, and every Markdown document opens with a `---` frontmatter block stating its title, description and canonical URL. ## Machine-readable surfaces - [Sitemap](https://agentic-atlas.dev/sitemap.xml): Every published address. - [AI catalog](https://agentic-atlas.dev/.well-known/ai-catalog.json): Every machine-readable surface, as JSON, for scanners that start at .well-known. - [Agent signpost](https://agentic-atlas.dev/agents.md): The same list in Markdown, for scanners that probe `/agents.md` by convention. - [MCP server card](https://agentic-atlas.dev/.well-known/mcp-server-card): The registry card for this server — name, version, transport. - [MCP tool card](https://agentic-atlas.dev/.well-known/mcp/server-card.json): The endpoint and complete frozen tool grammar as JSON. - [API catalog](https://agentic-atlas.dev/.well-known/api-catalog): The APIs this host publishes, as an RFC 9727 linkset. - [Pricing and usage policy](https://agentic-atlas.dev/pricing.md): What the Atlas costs, what it limits, and what it licenses. ## Versioning and change policy The Atlas versions by **Release**, not by URL path. Addresses are stable and are not prefixed with `/v1/`; what changes is the content behind them, and a promotion replaces the active Release wholesale rather than editing one in place. - Every response carries `X-Catalog-Revision`. Two responses with the same value describe the same Atlas. - MCP payloads carry a coherence marker. Pass it back as `expected_revision` and a call that would straddle a promotion is refused rather than silently answered from two Releases. - The tool grammar is frozen. Tools are added compatibly. - Every JSON API response carries `API-Version: 1`. Additive changes retain that value; a breaking change increments it. - A deprecated operation carries `Deprecation: true` and an HTTP-date `Sunset` for at least 180 days before removal. Its OpenAPI operation is marked `deprecated: true` for the same interval. No operation is deprecated today. - Rate limits are published, not discovered by hitting them. The JSON API allows 300 requests per minute per address; the analytics count proxy allows 60. Both state the window on every response — `RateLimit-Limit`, `RateLimit-Remaining`, `RateLimit-Reset`, and the combined `RateLimit` field — with `Retry-After` on a 429, so a client can throttle itself rather than wait to be refused. The pages and the MCP transport are not limited. ## About - [About](https://agentic-atlas.dev/about): Who publishes this. - [Contact](https://agentic-atlas.dev/contact): How to reach the publisher. - [Privacy](https://agentic-atlas.dev/privacy): What this site records, and what it does not.