tc39-mcp
io.github.xyzzylabs/tc39-mcp · v0.6.1 · MCP 2024-11-05
Independent MCP server for the TC39 specs (ECMA-262 + ECMA-402): clauses, search, diffs, history.
Reachability
reachable
checked 2026-07-14 04:30 UTC
Registry status active
Tools pinned 17
ef0561670015
Tools last changed
unchanged since first capture 2026-07-14
Provenance
Registry namespace io.github.xyzzylabs
(GitHub-account verified by the official registry)
Repository
github.com/xyzzylabs/tc39-mcp
Website
https://mcp.xyzzylabs.ai/tc39
Remote endpoints
https://mcp.xyzzylabs.ai/tc39/mcp (streamable-http)
Observed changes
| When (UTC) | Event | Detail |
|---|---|---|
| 2026-07-14 03:23 | first capture | 17 tools pinned |
Pinned tool definitions (17)
| Tool | Description |
|---|---|
| spec.about | Self-description of this MCP server: package name + version, per-snapshot pin metadata (sha, fetched_at, biblio_commit, clause_count) for every supported (spec, edition), plus test262 + proposals index headers when present. |
| clause.get | Fetch a parsed TC39 clause as structured JSON. `spec` selects '262' (default) or '402'. `edition` defaults to 'latest'. `at: '<sha>'` pins to a historical main snapshot (only valid for edition='main'); omit to query the live snapshot. |
| clause.list | List parsed spec clauses with optional filters (kind, section prefix, has_algorithm). `spec` selects '262' or '402'. `at: '<sha>'` queries a historical main snapshot. |
| spec.search | Search the parsed spec by clause id / aoid / title (+ step text with `search_steps`). Aoid-exact ranks first. `at: '<sha>'` searches a historical main snapshot. |
| proposal.list | List TC39 proposals from the static index (tc39/proposals). Filter by spec ('262'|'402'), stage ('0'|'1'|'2'|'2.7'|'3'|'finished'|'inactive'|'active'), champion (substring), or contains (name/slug substring). |
| proposal.get | Fetch one TC39 proposal by slug (exact) or name (case-insensitive). |
| spec.grammar | Query grammar productions captured from the spec's `<emu-grammar>` blocks. `{ nonterminal }` returns every production for that non-terminal (exact match); `{ contains }` filters by RHS / name substring; neither lists all non-terminals +... |
| spec.tables | List or fetch parsed `<emu-table>` content. `{ id }` returns exactly that table (full columns + rows); otherwise list table summaries, optionally narrowed by a `filter` substring over the caption or id. |
| spec.sdo_index | Index Syntax-Directed Operations by the grammar production they're defined on. `by: 'production'` (default) groups SDOs under each production; `by: 'sdo'` groups productions under each SDO title. `filter` narrows to keys containing a... |
| clause.outline | Return the section tree (table of contents) for a parsed (spec, edition). `depth` caps how deep the tree descends (1 = top-level only); `under` limits the tree to descendants of one clause id. |
| spec.global_search | Run spec.search across both ECMA-262 and ECMA-402 in one call and interleave hits by score. Each hit is tagged with the spec it came from. Use it when you don't know which spec defines a symbol. `search_steps` also matches algorithm step text. |
| spec.snapshots | List the live (spec, edition, sha, fetched_at) snapshots the hosted Worker is serving from R2. Filter by `spec` ('262'|'402') or `edition` (e.g. 'main', 'es2026'). Historical SHA-pinned copies are reachable via `at:` on clause.get /... |
| spec.symbol_resolve | Resolve spec notation like `[[Prototype]]` (internal slot), `%Object.prototype%` (well-known intrinsic), or `~number~` (sigil enum): return clauses that mention or define it, ranked by occurrence with a bump for definition-y sections. |
| spec.well_known_intrinsics | Enumerate the well-known intrinsics in a spec with their probable defining clauses. Driven from the canonical §6.1.7.4 WKI table when present (ECMA-262), else a `%X%` prose scan (e.g. ECMA-402). `filter` narrows by bare-name substring. |
| spec.diff | Clause-level diff of one clause across two editions of a spec. Reports identical / modified / added / removed plus a field-level breakdown (title, signature, step count, reworded step indices, notes, crossrefs). `from` defaults to the... |
| spec.crossrefs | For a clause id, return its outgoing references (clauses it cites) and/or incoming references (clauses that cite it — the back-reference index the parse alone doesn't expose). The reverse index is AOID-densified from step text.... |
| test262.search | Search the tc39/test262 conformance suite from its indexed front-matter. `query` AND-matches whitespace tokens (case-insensitive) across each test's description + path; `esid` prefix-matches the front-matter esid. Returns ranked hits... |
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