tabnas
REMOTE · MCP.TABNAS.DEV · 2 COMPONENTS · SCANNED SEP 25
Seven tools over the tabnas parsing engine: parse, validate, diagnose, fixtures, compare.
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 Security46
- 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 7 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 enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- 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 Usability88
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (excellent).Pass
- Tool/resource definitions use about 1119 tokens (~93/item across 12 items; 7 tools + 5 resources), lean.Pass
- 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 Coverage98
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 93% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 7 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 8 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
How do I install the tabnas MCP server?
tabnas is a hosted endpoint at https://mcp.tabnas.dev/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.tabnas.dev
claude mcp add --transport http dev-tabnas-mcp 'https://mcp.tabnas.dev/mcp'
{
"mcpServers": {
"dev-tabnas-mcp": {
"url": "https://mcp.tabnas.dev/mcp"
}
}
} {
"servers": {
"dev-tabnas-mcp": {
"type": "http",
"url": "https://mcp.tabnas.dev/mcp"
}
}
} [mcp_servers.dev-tabnas-mcp] url = "https://mcp.tabnas.dev/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"dev-tabnas-mcp": {
"type": "remote",
"url": "https://mcp.tabnas.dev/mcp",
"enabled": true
}
}
} openclaw mcp add dev-tabnas-mcp --url 'https://mcp.tabnas.dev/mcp' --transport streamable-http
mcp_servers:
dev-tabnas-mcp:
url: "https://mcp.tabnas.dev/mcp" {
"McpServers": {
"dev-tabnas-mcp": {
"Transport": "http",
"Url": "https://mcp.tabnas.dev/mcp"
}
}
} assistant mcp add dev-tabnas-mcp -t streamable-http -u 'https://mcp.tabnas.dev/mcp'
{
"mcpServers": {
"dev-tabnas-mcp": {
"type": "http",
"url": "https://mcp.tabnas.dev/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.
- 25 Sept 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
- 24 Sept 26 0
- Server version: 0.1.15 → 0.1.16 functional
- 19 Sept 26 0
- Stability: 0.97 → pass security
- 17 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 15 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.
- 13 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.
- 9 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.
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 25 Sept 2026 · Probed https://mcp.tabnas.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=tabnas.dev | CN=WE1,O=Google Trust Services,C=US | 19 Aug 2026 | 17 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | 56e3afa740a1f7890e182abc457151f3 |
| SANs: tabnas.dev, mcp.tabnas.dev, *.mcp.tabnas.dev | ||||||
| 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.tabnas.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| tabnas.dev. | 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 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.tabnas.dev/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.tabnas.dev/mcp | Inconclusive | 405 |
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 →
compare_grammars ~220
Grammar compatibility (AX plan Phase 5): does candidate grammar B still accept what baseline A accepted, and does it build the same tree for inputs both accept? Returns EVIDENCE AND CONFIDENCE, never a bare verdict: {normalForm, proven[], observed[], changes[], counterexamples[], confidence, why}. confidence:'low' with a stated reason is a successful run, not a failure — language inclusion is undecidable in general, so anything outside the decidable subset is reported not-proven rather than incompatible. Supply `corpus` (real inputs) for the tier that measures what your documents actually do.
| Name | Type | Req | Description |
|---|---|---|---|
| a | object | yes | Baseline grammar: the serialized GrammarSpec already deployed. |
| b | object | yes | Candidate grammar: the serialized GrammarSpec proposed to replace it. |
| corpus | array | – | Inputs to replay through both grammars, comparing acceptance and tree shape. |
| depth | integer | – | Derivation depth for generated inputs (default 3). |
| options | object | – | TabnasOptions applied to both instances. |
No output schema declared.
No examples provided.
describe_plugin ~55
The full descriptor for one plugin, by package name ('@tabnas/csv') or bare fleet name ('csv'). Unknown names get {ok:false, errors} naming the known plugins.
| Name | Type | Req | Description |
|---|---|---|---|
| name | string | yes | Plugin name. |
No output schema declared.
No examples provided.
explain_parse_error ~140
Parse input and explain the failure. Returns {failed:false} when the input parses; otherwise {failed:true, diagnostic, registry} where registry is the error-code registry entry {code,message,hint} for the diagnostic code (resource tabnas://errors), or null for a code the bundled registry does not know (e.g. a plugin-declared code).
| Name | Type | Req | Description |
|---|---|---|---|
| grammar | object | – | Serialized GrammarSpec (pure JSON, no functions). Schema: resource tabnas://schema/grammar. Grammars are validated before use; a `ref` key or a non-builtin function reference is rejected. |
| input | string | yes | Source text to parse. |
No output schema declared.
No examples provided.
list_plugins ~36
List every bundled tabnas plugin descriptor (tabnas.plugin.json of each fleet repo), sorted by name. Returns {plugins:[...]}.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
parse ~174
Parse input with the tabnas engine. Returns {ok:true, tree} or, on parse failure, {ok:false, diagnostic} — the structured diagnostic described by resource tabnas://schema/diagnostic. An invalid grammar is rejected as {ok:false, errors:[{path,message}]}. Without a grammar the bare engine is used, which defines no rules and produces an undefined tree for every input.
| Name | Type | Req | Description |
|---|---|---|---|
| grammar | object | – | Serialized GrammarSpec (pure JSON, no functions). Schema: resource tabnas://schema/grammar. Grammars are validated before use; a `ref` key or a non-builtin function reference is rejected. |
| input | string | yes | Source text to parse. |
| options | object | – | TabnasOptions applied to the fresh instance before the grammar. Data only: a plugins entry is rejected. |
No output schema declared.
No examples provided.
test_grammar ~155
Run TSV fixture content against a grammar in a fresh instance, using the fleet fixture convention (@tabnas/support): line 1 is a header, the input column is escape-decoded, the expected column is JSON or ERROR / ERROR:<code>. Returns {pass, fail, rows:[{row,input,expected,got,ok}]}. Refuses more than 10000 rows.
| Name | Type | Req | Description |
|---|---|---|---|
| grammar | object | – | Serialized GrammarSpec (pure JSON, no functions). Schema: resource tabnas://schema/grammar. Grammars are validated before use; a `ref` key or a non-builtin function reference is rejected. |
| options | object | – | – |
| spec | string | yes | TSV fixture content (not a path). |
No output schema declared.
No examples provided.
validate_grammar ~188
Validate a serialized GrammarSpec. Structural validation against the bundled grammar schema, an engine load in a fresh instance, and a check that every rule reference (`p`, `r`) names a rule the grammar actually defines — a dangling reference loads cleanly and then fails at parse time with `unknown_rule`. Returns {ok:true, v} (v = declared builtin config-schema version, absent means 1) or {ok:false, errors:[{path,message}]}. Security: a grammar carrying a `ref` key, or any function reference that is not a $-suffixed engine builtin, is rejected — validating a grammar never runs supplied code.
| Name | Type | Req | Description |
|---|---|---|---|
| grammar | object | yes | Serialized GrammarSpec (pure JSON, no functions). Schema: resource tabnas://schema/grammar. Grammars are validated before use; a `ref` key or a non-builtin function reference is rejected. |
No output schema declared.
No examples provided.
What is the tabnas MCP server?
tabnas is an MCP server listed in the public MCP registry as dev.tabnas/mcp. Seven tools over the tabnas parsing engine: parse, validate, diagnose, fixtures, compare. This page covers its hosted endpoint (https://mcp.tabnas.dev/mcp).
Is the tabnas MCP server safe to use?
tabnas scores 74 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 tabnas MCP server expose?
tabnas exposes 7 tools: parse, validate_grammar, explain_parse_error, test_grammar, list_plugins, and 2 more. Their descriptions and schemas cost roughly 968 tokens of context every time the server is loaded.
Does the tabnas MCP server require authentication?
No. We connected to tabnas without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the tabnas MCP server still maintained?
tabnas is still listed as active in the MCP registry. We last reached this channel on 25 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.