wasm-mcp
REMOTE · MCP.XYZZYLABS.AI · 2 COMPONENTS · SCANNED SEP 20
Read-only MCP server for the WebAssembly spec: instructions, types, sections, search, proposals.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 9 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability69
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1592 tokens (~176/item across 9 items; 9 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 9 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 10 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities20
- Spec-recency check failed: implements MCP spec 2024-11-05; the latest is 2026-07-28. See how to fix → Fail
How do I install the wasm-mcp server?
wasm-mcp is a hosted endpoint at https://mcp.xyzzylabs.ai/wasm/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · mcp.xyzzylabs.ai
claude mcp add --transport http xyzzylabs-wasm-mcp 'https://mcp.xyzzylabs.ai/wasm/mcp'
{
"mcpServers": {
"xyzzylabs-wasm-mcp": {
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
} {
"servers": {
"xyzzylabs-wasm-mcp": {
"type": "http",
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
} [mcp_servers.xyzzylabs-wasm-mcp] url = "https://mcp.xyzzylabs.ai/wasm/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"xyzzylabs-wasm-mcp": {
"type": "remote",
"url": "https://mcp.xyzzylabs.ai/wasm/mcp",
"enabled": true
}
}
} openclaw mcp add xyzzylabs-wasm-mcp --url 'https://mcp.xyzzylabs.ai/wasm/mcp' --transport streamable-http
mcp_servers:
xyzzylabs-wasm-mcp:
url: "https://mcp.xyzzylabs.ai/wasm/mcp" {
"McpServers": {
"xyzzylabs-wasm-mcp": {
"Transport": "http",
"Url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
} assistant mcp add xyzzylabs-wasm-mcp -t streamable-http -u 'https://mcp.xyzzylabs.ai/wasm/mcp'
{
"mcpServers": {
"xyzzylabs-wasm-mcp": {
"type": "http",
"url": "https://mcp.xyzzylabs.ai/wasm/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 26 Aug 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 24 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 0
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Probed https://mcp.xyzzylabs.ai/wasm/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=xyzzylabs.ai | CN=WE1,O=Google Trust Services,C=US | 23 Aug 2026 | 21 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | 35646096399f37e70e0f4daf7cc94be2 |
| SANs: xyzzylabs.ai, mcp.xyzzylabs.ai, *.mcp.xyzzylabs.ai | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.xyzzylabs.ai. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| ai. | present | 3799 | 8 | Verified |
| xyzzylabs.ai. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000 |
| x-content-type-options | nosniff |
| x-frame-options | DENY |
| referrer-policy | strict-origin-when-cross-origin |
| permissions-policy | camera=(), microphone=(), geolocation=(), browsing-topics=() |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.xyzzylabs.ai/wasm/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.xyzzylabs.ai/wasm/mcp | HTTPS enforced | 308 | https://mcp.xyzzylabs.ai/wasm/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
instruction_get ~146
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 trap conditions with canonical names; empty + `can_trap:false` when it never traps).
| Name | Type | Req | Description |
|---|---|---|---|
| mnemonic | string | – | Instruction mnemonic, e.g. `i32.add`. Case-insensitive, exact. |
| opcode | string | – | Binary opcode hex, e.g. `0x6a` or `0xfd 0x89 0x02`. Exact. |
No output schema declared.
No examples provided.
instruction_list ~133
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.
| Name | Type | Req | Description |
|---|---|---|---|
| can_trap | boolean | – | Keep only instructions that can (true) / cannot (false) trap. |
| category | string | – | Instruction category. |
| introduced_in | string | – | Introducing version. |
| prefix | string | – | Mnemonic prefix, e.g. `i32.`. Case-insensitive. |
No output schema declared.
No examples provided.
instruction_search ~52
Ranked free-text search across instruction mnemonics, categories, and opcode hex. Returns hits with a `matched_on` field.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max hits. |
| query | string | yes | Search text. |
No output schema declared.
No examples provided.
proposal_list ~117
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`.
| Name | Type | Req | Description |
|---|---|---|---|
| affects | string | – | Affected spec (finished only). |
| champion | string | – | Champion substring. |
| contains | string | – | Name/champion substring. |
| phase | integer | – | Numeric phase 0–5. |
| status | string | – | Lifecycle status. |
No output schema declared.
No examples provided.
section_get ~91
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.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Clause id or anchor. |
| spec | string | – | Which spec (default core). |
No output schema declared.
No examples provided.
section_list ~128
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`.
| Name | Type | Req | Description |
|---|---|---|---|
| anchor_prefix | string | – | Id/anchor prefix. |
| max_level | integer | – | Cap heading depth. |
| path | string | – | Source path / prefix. |
| spec | string | – | Which spec (default core). |
| titled_only | boolean | – | Drop anchor-only blocks. |
No output schema declared.
No examples provided.
spec_search ~82
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.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | Max hits. |
| query | string | yes | Search text. |
| spec | string | – | Which spec (default core). |
No output schema declared.
No examples provided.
spec_version ~29
Return this server's package version plus the pinned upstream commit SHA(s) the bundled data was indexed from.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
type_get ~77
Look up a value type (`i32`, `funcref`, `v128`, …) or type form (`functype`, `limits`, `memtype`, …): classification, sibling members, defining clause prose, formal refs, and URL.
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | Type or type-form name. Case-insensitive, exact. |
No output schema declared.
No examples provided.
What is the wasm-mcp server?
wasm-mcp is listed in the public MCP registry as io.github.xyzzylabs/wasm-mcp. Read-only MCP server for the WebAssembly spec: instructions, types, sections, search, proposals. This page covers its hosted endpoint (https://mcp.xyzzylabs.ai/wasm/mcp).
Is the wasm-mcp server safe to use?
wasm-mcp scores 76 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the wasm-mcp server expose?
wasm-mcp exposes 9 tools: spec_version, instruction_get, instruction_list, instruction_search, type_get, and 4 more. Their descriptions and schemas cost roughly 855 tokens of context every time the server is loaded.
Does the wasm-mcp server require authentication?
No. We connected to wasm-mcp without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the wasm-mcp server still maintained?
wasm-mcp is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.