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External endpointresponds

tc39-mcp

Independent MCP server for the TC39 specs (ECMA-262 + ECMA-402): clauses, search, diffs, history.

Endpoint URL
https://mcp.xyzzylabs.ai/tc39/mcp
Current status
responds
Last checked
Aug 17, 2026, 05:05 AM UTC
Check
MCP initialize · 8s limit
Latency
194 ms
Response record
4 of 4 rounds
Transport
streamable-http
Source
mcp_registry
Registry name
io.github.xyzzylabs/tc39-mcp

Current observation

This endpoint answered at its latest recorded check.

What this server reports about itself

Self-reported at initialize. Not verified by Licium.

Server name
tc39-mcp
Version
0.6.2
Capability keys
tools, prompts
Tool names
spec.about, clause.get, clause.list, spec.search, proposal.list, proposal.get, spec.grammar, spec.tables, spec.sdo_index, clause.outline, spec.global_search, spec.snapshots, spec.symbol_resolve, spec.well_known_intrinsics, spec.diff, spec.crossrefs, test262.search
Instructions excerpt

tc39-mcp serves read-only structured data from the TC39 specs (ECMA-262 + ECMA-402), tc39/test262, and tc39/proposals. Every response is deterministic over data pinned to specific upstream SHAs. Independent project — not an official Ecma International or TC39 publication. This is the hosted Cloudflare Worker deployment — 17 of the 19 tools (call tools/list for the set). The 2 stdio-only ones (spec.history, test262.get) are available via the stdio server (npx tc39-mcp). Common workflow: 1. `spec.about` — call first to see what SHAs and editions the server is serving. Returns per-snapshot pin metadata. 2. `spec.search` — find a clause from a name or symptom. Hits rank aoid-exact > aoid-substring > title > id; follow up with `clause.get { id }` to read the full clause. To find clauses by what they DO (e.g. which clauses invoke OrdinaryGetOwnProperty), pass search_steps: true to also scan algorithm step text — off by default since it is slower

Reported Aug 17, 2026, 05:05 AM UTC.

Check history

Oldest to newest. Each row is one recorded check.

  1. responds
    MCP initialize · 8s limit · HTTP 200 · 95ms
  2. responds
    MCP initialize · 8s limit · HTTP 200 · 523ms
  3. responds
    MCP initialize · 8s limit · HTTP 200 · 101ms
  4. responds
    MCP initialize · 8s limit · HTTP 200 · 194ms
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