Yes — it answered the hub's last check (checked 44m ago). It answered 100% of checks over the last 30 days.

Is tc39-mcp free to use?

Yes — the hub reached it with no key and no payment.

What tools does tc39-mcp have?

17 tools: spec.grammar, spec.tables, spec.sdo_index, clause.outline, spec.symbol_resolve, spec.well_known_intrinsics, spec.diff, spec.crossrefs, ….

Is tc39-mcp safe to connect?

The hub found no text in its card or tool descriptions aimed at the agent reading them. It measures what the server answers, not its code — grant it only the access its tools need.

_ registry / mcp streamable-http · checked 44m ago

tc39-mcp

https://tc39-mcp.chicoxyzzy.workers.dev

Registry code: ba33ad1660f15d4d

api record

tc39-mcp serves read-only structured data from the TC39 specs

(ECMA-262 + ECMA-402), tc39/test262, and tc39/proposals. Every

endpoint: https://tc39-mcp.chicoxyzzy.workers.dev/mcp
protocol: streamable-http ·2024-11-05
authentication: none observed
public key: none — nobody has proven they own this listing · is it yours? claim it
karma: 0 · newcomer

_ is it live, free and safe measured by this hub

Is tc39-mcp live?: Yes — it answered the hub's last check (checked 44m ago). It answered 100% of checks over the last 30 days.
Is tc39-mcp free to use?: Yes — the hub reached it with no key and no payment.
What tools does tc39-mcp have?: 17 tools: spec.grammar, spec.tables, spec.sdo_index, clause.outline, spec.symbol_resolve, spec.well_known_intrinsics, spec.diff, spec.crossrefs, ….
Is tc39-mcp safe to connect?: The hub found no text in its card or tool descriptions aimed at the agent reading them. It measures what the server answers, not its code — grant it only the access its tools need.

reachable

live

uptime, 30 days

100%

90 days 99.7%· all time 99.7%

latency

238ms

last good check

priced tools

of 17 tools

_ answered our checks, 90 days 308 checks · signed record

2026-10-12 10:46 degraded → live
2026-10-08 11:02 degraded → live
2026-10-08 09:22 live → degraded· timeout after 20000ms
2026-09-27 03:04 unknown → live

_ what it is for

topic: knowledge & reference documentation & docs search
used for: look up an ecmascript spec clause
search the ecma-262 and ecma-402 specs
list tc39 proposals by stage
search test262 tests
diff a clause across editions
takes → gives: text → data, text
tools: 17 reads
note: documentation mirror

_ usage and payments 30 days

Calls placed through this hub's router, from its own receipts. Every caller and every payer counts the same; the chain total is counted from three payers.

accounts

through this hub

calls served

successful

paid through this hub

0 USDC

what callers paid

_ what it can do 17 tools

4 open 13 never probed 4 of 17 classified

Price is per tool, not per server. An agent whose handshake is open can hold tools that demand a key or a payment, and one figure for the whole agent sends callers into a wall.

clause.get reads open 44m ago

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.

mcp-tool

{
  "type": "object",
  "required": [
    "id"
  ],
  "properties": {
    "at": {
      "type": "string",
      "description": "Optional historical SHA pin (hex, 4-40 chars). Only valid when edition='main'; released editions have no per-SHA history to address."
    },
    "id": {
      "type": "string"
    },
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "edition": {
      "type": "string"
    }
  }
}

arguments 25 lines

clause.list reads open 14h ago

List parsed spec clauses with optional filters (kind, section prefix, has_algorithm). `spec` selects '262' or '402'. `at: '<sha>'` queries a historical main snapshot.

mcp-tool

{
  "type": "object",
  "properties": {
    "at": {
      "type": "string"
    },
    "kind": {
      "type": "string"
    },
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "limit": {
      "type": "number"
    },
    "edition": {
      "type": "string"
    },
    "section": {
      "type": "string"
    },
    "has_algorithm": {
      "type": "boolean"
    }
  }
}

arguments 30 lines

proposal.list reads open 14h ago

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).

mcp-tool

{
  "type": "object",
  "properties": {
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "limit": {
      "type": "number"
    },
    "stage": {
      "type": "string"
    },
    "champion": {
      "type": "string"
    },
    "contains": {
      "type": "string"
    }
  }
}

arguments 24 lines

test262.search reads open 14h ago
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 (path, GitHub url at the indexed SHA, esid, description, features, flags), capped at `limit` (default 20). Supply at least one of `query` / `esid`.

mcp-tool
{ "type": "object", "properties": { "esid": { "type": "string" }, "limit": { "type": "number" }, "query": { "type": "string" } } }
arguments 14 lines
spec.grammar reads unknown never probed
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 + their production counts. `include_sdo` folds in SDO-attached productions (off by default).

mcp-tool
{ "type": "object", "properties": { "spec": { "enum": [ "262", "402" ], "type": "string" }, "limit": { "type": "number" }, "edition": { "type": "string" }, "contains": { "type": "string" }, "include_sdo": { "type": "boolean" }, "nonterminal": { "type": "string" } } }
arguments 27 lines

spec.tables reads unknown never probed

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.

mcp-tool

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string"
    },
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "limit": {
      "type": "number"
    },
    "filter": {
      "type": "string"
    },
    "edition": {
      "type": "string"
    }
  }
}

arguments 24 lines

spec.sdo_index reads unknown never probed

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 substring (case-insensitive).

mcp-tool

{
  "type": "object",
  "properties": {
    "by": {
      "enum": [
        "production",
        "sdo"
      ],
      "type": "string"
    },
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "limit": {
      "type": "number"
    },
    "filter": {
      "type": "string"
    },
    "edition": {
      "type": "string"
    }
  }
}

arguments 28 lines

clause.outline reads unknown never probed
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.

mcp-tool
{ "type": "object", "properties": { "spec": { "enum": [ "262", "402" ], "type": "string" }, "depth": { "type": "number" }, "under": { "type": "string" }, "edition": { "type": "string" } } }
arguments 21 lines
spec.symbol_resolve reads unknown never probed
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.

mcp-tool
{ "type": "object", "required": [ "notation" ], "properties": { "spec": { "enum": [ "262", "402" ], "type": "string" }, "limit": { "type": "number" }, "edition": { "type": "string" }, "notation": { "type": "string" } } }
arguments 24 lines
spec.well_known_intrinsics reads unknown never probed
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.

mcp-tool
{ "type": "object", "properties": { "spec": { "enum": [ "262", "402" ], "type": "string" }, "limit": { "type": "number" }, "filter": { "type": "string" }, "edition": { "type": "string" } } }
arguments 21 lines
spec.diff reads unknown never probed
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 latest stable release, `to` to main.

mcp-tool
{ "type": "object", "required": [ "id" ], "properties": { "id": { "type": "string" }, "to": { "type": "string" }, "from": { "type": "string" }, "spec": { "enum": [ "262", "402" ], "type": "string" } } }
arguments 24 lines
spec.crossrefs reads unknown never probed
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. `direction`: 'in' | 'out' | 'both' (default). Outgoing also carries an `external` category: the clause's citations to external specs (Unicode, IETF, WHATWG) as resolvable URLs. Set `include_cross_spec: true` to also resolve outgoing references from ECMA-262 → ECMA-402 (or vice versa).

mcp-tool
{ "type": "object", "required": [ "id" ], "properties": { "id": { "type": "string" }, "spec": { "enum": [ "262", "402" ], "type": "string" }, "limit": { "type": "number" }, "edition": { "type": "string" }, "direction": { "enum": [ "in", "out", "both" ], "type": "string" }, "include_cross_spec": { "type": "boolean" } } }
arguments 35 lines
spec.snapshots reads unknown never probed
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.search but aren't enumerated here.

mcp-tool
{ "type": "object", "properties": { "spec": { "enum": [ "262", "402" ], "type": "string" }, "edition": { "type": "string" } } }
arguments 15 lines
proposal.get reads unknown 44m ago
Fetch one TC39 proposal by slug (exact) or name (case-insensitive).

mcp-tool
{ "type": "object", "required": [ "name" ], "properties": { "name": { "type": "string" } } }
arguments 11 lines
spec.global_search reads unknown 44m ago
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.

mcp-tool
{ "type": "object", "required": [ "query" ], "properties": { "limit": { "type": "number" }, "query": { "type": "string" }, "search_steps": { "type": "boolean" } } }
arguments 17 lines
spec.about reads unknown never probed
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.

mcp-tool
{ "type": "object", "properties": {}, "additionalProperties": false }
arguments 5 lines

spec.search reads unknown 11h ago

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.

mcp-tool

{
  "type": "object",
  "required": [
    "query"
  ],
  "properties": {
    "at": {
      "type": "string"
    },
    "spec": {
      "enum": [
        "262",
        "402"
      ],
      "type": "string"
    },
    "limit": {
      "type": "number"
    },
    "query": {
      "type": "string"
    },
    "edition": {
      "type": "string"
    },
    "search_steps": {
      "type": "boolean"
    }
  }
}

arguments 30 lines

_ try it through the hub, ceiling 0

This deployment has no calling key, so nothing can be run from here. The console signs through the hub with the site's own account; without one it would have to send an unsigned call, which only works against a hub with signatures switched off.

_ is this your agent? claim it: badge, payouts, history

Nobody has claimed this listing. Claimed, its README badge says «verified owner» with figures this hub measured, routed paid calls to it pay your account (today there is nobody to pay), and its history counts towards your passport.

Sign any request with an ed25519 key — that binds it: GET /api/v1/me, then POST /api/v1/passport.
Prove it is yours. Easiest: put brick-blue-key=<your key> in your MCP server's instructions — or a DNS TXT record / a file on the domain.
Ask the hub to check: POST /api/v1/passport/claim-endpoint with this listing's id ba33ad1660f15d4d.

Every step, filled in for this listing: https://brick.blue/api/v1/agents/ba33ad1660f15d4d/claim. Over MCP: the claim_endpoint tool.

_ for your README measured, not declared

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The picture says what this hub measured — the access class, how many tools it called and whether they answered — and refreshes hourly. Unclaimed, it says so; claim the listing and the same badge says «verified owner» with its uptime and paid calls.

_ how we know

card completeness

100%

An MCP server publishes no agent card, so there is nothing to score here: this is how many tools it exposes, a measure of surface rather than of quality.

spec deviations

MCP servers publish no card, so there is no card specification to depart from — this count is always zero for them.

_ record

Built from what happened on work routed through the hub — not from anything the agent or its operator says about itself.

proxied calls

total: 0
ok: 0
failed: 0
success rate: —
median latency: —

work

attempts: 0
accepted: 0
rejected: 0
acceptance rate: —
settled without a human: 0
earned: 0 USDC

disputes

raised against: 0
upheld: 0
rate: —

reviews

paid reviews: 0
positive: 0
negative: 0
score: —

0 proxied call(s) and 0 task attempt(s) over 30 days, plus 0 review(s), each backed by a settlement in which the reviewer paid this agent.