WebMCP

The documentation site itself is a WebMCP-enabled page: it runs an MCP server in your browser, so any MCP client (Claude Desktop, Cursor, Cline, Windsurf) can connect directly and call neuron-js tools in your browser — no backend, no API keys, no installation.

How to connect

1. Configure your MCP client once:

{ "mcpServers": { "webmcp": { "command": "npx", "args": ["-y", "@jason.today/webmcp@latest", "--mcp"] } } }

2. Ask your client to generate a WebMCP token (npx -y @jason.today/webmcp --new also works).
3. Click the widget in the bottom-right corner of any page of this site and paste the token.
4. The tools appear in your client (restart the client if you do not see them).

Tools exposed by this site

Tool	What it does
validate_script	Validates an ExecutionScript against the neuron-js schema without executing it.
execute_decision	Validates and executes an ExecutionScript against an ExecutionContext; returns the summarized output.
explain_decision	Same as execute_decision plus the explanation trace.

These are the same three tools exposed by the stdio MCP server shipped in examples/mcp-server — same contracts, same fail-closed validation. The difference: the runtime here is the real @sebasoft/neuron-js loaded from the npm registry and executed in your browser. The library is browser-safe (zero node: imports), so the exact engine that runs on a server also runs in the page.

Two resources are also exposed: the compact llms.txt index and the official SKILL.md AI skill, both served by this site.

Guarantees

• Fail-closed: every call validates script and context first; invalid input returns the exact validation errors and never executes.
• No side effects: tools return JSON only; nothing on the page is mutated.
• Your model, your keys: the site never touches an LLM; your MCP client does the inference. The site is only the tool surface.

Provenance and status

Two complementary surfaces ship on this site:

• Native W3C WebMCP API (navigator.modelContext): enabled on sebasoft.github.io through an active Chrome origin trial (expires 2026-11-17). When a Chrome browser honors the trial, the same three tools register through the standard API directly.
• WebMCP widget (@jason.today/webmcp): the original open-source proposal — not the W3C spec — that works in any browser today via a localhost websocket bridge and a connection token.

The site registers the tools on both surfaces; native when available, widget always. GitHub Pages cannot serve custom headers (Origin-Agent-Cluster, Permissions-Policy), so the origin-trial meta tag is the enabling mechanism here.

Scope

Read-only documentation surface. The tools execute example-scale scripts; they are not a hosted execution service. For production use, run neuron-js in your own runtime, or embed the stdio MCP server.