Connect wasm-mcp and your agent gets 9 tools, among them instruction_get, instruction_list, instruction_search. It answers at https://mcp.xyzzylabs.ai/wasm/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 6 of 6 times since 11 September 2026; the last check, on 24 October 2026, succeeded.
Read-only MCP server for the WebAssembly spec: instructions, types, sections, search, proposals.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
instruction_get | Fetch one WebAssembly instruction by mnemonic (`i32.add`) or binary opcode (`0x6a`, multi-byte `0xfd 0x89 0x02`): opcode bytes, category, introducing version, stack type signature, validation/execution anchors + URLs, and `traps` (runtime t Inputs: mnemonic, opcode |
instruction_list | Enumerate WebAssembly instructions, filterable by `category`, `introduced_in` (1.0|2.0|3.0), mnemonic `prefix`, and `can_trap` (only trapping / only non-trapping). Rows (incl. `can_trap`) sorted by opcode. Inputs: category, introduced_in, prefix, can_trap |
instruction_search | Ranked free-text search across instruction mnemonics, categories, and opcode hex. Returns hits with a `matched_on` field. Inputs: query, limit |
proposal_list | List WebAssembly proposals + phases. Filter by `status` (phase-0…phase-5, finished, inactive), `phase` (0–5), `champion`, `affects` (core|js-api|web-api), or `contains`. Inputs: status, phase, champion, affects, contains |
section_get | Fetch one spec clause by id or anchor across `core` / `js-api` / `web-api` (`syntax-numtype`, `valid-unreachable`, `modules`, `streaming-modules`, …): title, prose, cross-references, SpecTec formal refs, and rendered URL. Inputs: id, spec |
section_list | Navigate the clause tree of a spec (`core` / `js-api` / `web-api`), filterable by source `path` (`syntax`, `valid`, `exec`, `binary`, `text`, `appendix`), `anchor_prefix`, `titled_only`, and `max_level`. Inputs: spec, path, anchor_prefix, titled_only, max_level |
spec_search | Full-text search across clause anchors, titles, and prose of a spec (`core` / `js-api` / `web-api`). Ranked anchor-exact > title > anchor > prose, with snippets for body matches. Inputs: query, spec, limit |
spec_version | Return this server's package version plus the pinned upstream commit SHA(s) the bundled data was indexed from. |
type_get | Look up a value type (`i32`, `funcref`, `v128`, …) or type form (`functype`, `limits`, `memtype`, …): classification, sibling members, defining clause prose, formal refs, and URL. Inputs: name |
Every block below points at https://mcp.xyzzylabs.ai/wasm/mcp. Pick your client and copy.
claude mcp add --transport http wasm-mcp https://mcp.xyzzylabs.ai/wasm/mcp
{
"mcpServers": {
"wasm-mcp": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://mcp.xyzzylabs.ai/wasm/mcp"]
}
}
}{
"mcpServers": {
"wasm-mcp": {
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"servers": {
"wasm-mcp": {
"type": "http",
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"context_servers": {
"wasm-mcp": {
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"mcpServers": {
"wasm-mcp": {
"serverUrl": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"mcpServers": {
"wasm-mcp": {
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}name: wasm-mcp
version: 0.0.1
schema: v1
mcpServers:
- name: wasm-mcp
type: streamable-http
url: https://mcp.xyzzylabs.ai/wasm/mcp{
"mcpServers": {
"wasm-mcp": {
"httpUrl": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"mcpServers": {
"wasm-mcp": {
"type": "http",
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}{
"mcpServers": {
"wasm-mcp": {
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fmcp.xyzzylabs.ai%2Fwasm%2Fmcp&type=streamable_http&id=wasm-mcp&name=wasm-mcp
It answered our last check on 24 October 2026 in 136 ms. Over 6 checks since 11 September 2026 it answered 6. Status here comes from Neuronto's own probes, not from the publisher.
9, as returned by the server's own tools/list on 22 September 2026: instruction_get, instruction_list, instruction_search, proposal_list, section_get, section_list, spec_search, spec_version, and 1 more.
It answered our last check on 24 October 2026 in 136 ms. Over 6 checks since 11 September 2026 it answered 6.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://mcp.xyzzylabs.ai/wasm/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: io.github.xyzzylabs. Endpoint host: mcp.xyzzylabs.ai. ARD identifier: urn:air:io.github.xyzzylabs:mcp:wasm-mcp.
First indexed 10 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.