io.github.lemmaoracle/mcp
REMOTE · MCP.LEMMA.WORKERS.DEV · 2 COMPONENTS
Verifiable provenance for AI agents — ZK proofs over confidential documents, no plaintext exposure.
Available components
Last scanned (9 hours ago)
Scores higher than 81% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Security
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
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 406, 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 Usability71
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 949 tokens (~189/item across 5 items; 5 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
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
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.
- 28 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
- 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
- 26 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
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 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
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 5 Nov 2026 · Probed https://mcp.lemma.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=lemma.workers.dev | CN=YE1,O=Let's Encrypt,C=US | 29 Oct 2026 | 27 Jan 2027 | ECDSA 256 | ECDSA-SHA384 | 6040ab7b0b7f15f2935e4dc8693f07d6122 |
| SANs: *.lemma.workers.dev, lemma.workers.dev | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.lemma.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.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.lemma.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.lemma.workers.dev/mcp | Inconclusive | 406 |
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 →
lemma_get_circuit ~200
Retrieve a zero-knowledge proof circuit by its circuitId via GET /v1/circuits/{circuitId}. A circuit defines the constraints that proofs must satisfy and binds to a single schema. Returns CircuitMeta { circuitId, schema, description?, inputs?, verifier?: { type: 'onchain'|'offchain', address?, chainId? }, artifact?: { location: { type: 'ipfs'|'https', wasm, zkey } } }. Use this before lemma_submit_proof to confirm the circuit's schema, public inputs, and verifier configuration. Circuits are immutable; new variants get new circuitIds.
| Name | Type | Req | Description |
|---|---|---|---|
| circuitId | string | yes | Circuit ID. Returned in the `proof.circuitId` field of VerifiedAttributesQueryResponseItem from lemma_query_verified_attributes, or registered via POST /v1/circuits. NOTE: this matches the OpenAPI fi… |
| Name | Type | Req | Description |
|---|---|---|---|
| artifact | object | – | Circuit artifact location (WASM + zkey). |
| circuitId | string | yes | Circuit ID, echoing the request. |
| description | string | – | – |
| inputs | array | – | Ordered names of the circuit's public/private inputs. |
| schema | string | yes | Schema ID this circuit is bound to. |
| verifiers | array | – | Available verifier configurations for this circuit. |
No examples provided.
lemma_get_generator ~168
Retrieve a Lemma document generator by generatorId via GET /v1/doc-generators/{generatorId}. A generator describes how a class of source documents is produced (e.g., what fields a 'KYC-v2' issuer must populate). Returns GeneratorMeta { generatorId, schema, description?, language?, source?: { type: 'url', uri }, inputsSpec?, outputsSpec? }. Each generator is bound to one schema. Use this when onboarding a new issuer or auditing how an existing schema is being populated.
| Name | Type | Req | Description |
|---|---|---|---|
| generatorId | string | yes | Generator ID. Each generator is bound to a single schema and describes how source documents are produced. Registered via POST /v1/doc-generators. NOTE: this matches the OpenAPI field name `generatorI… |
| Name | Type | Req | Description |
|---|---|---|---|
| description | string | – | – |
| generatorId | string | yes | Generator ID, echoing the request. |
| inputsSpec | object | – | Specification of fields the issuer must populate. |
| language | string | – | Implementation language (e.g. 'rust', 'typescript'). |
| outputsSpec | object | – | Specification of fields the generator produces. |
| schema | string | yes | Schema ID this generator is bound to (1:1 binding). |
| source | object | – | Reference to the generator's source code. |
No examples provided.
lemma_get_proof_status ~204
Get the verification status of a proof. NOTE: the v2 API does not yet expose a dedicated GET /v1/proofs/{id} endpoint, so this tool internally calls POST /v1/verified-attributes/query filtered by docHash (treating the verificationId returned from lemma_submit_proof as a docHash filter). Returns { status, circuitId, chainId, docHash } extracted from the matched item, or undefined if the verificationId is unknown. Status enum: received | verified | onchain-verified | rejected. Use the SDK's isVerified() helper (or check status === 'verified' || status === 'onchain-verified') to determine cryptographic validity.
| Name | Type | Req | Description |
|---|---|---|---|
| verificationId | string | yes | verificationId returned by lemma_submit_proof. Internally treated as a docHash filter on POST /v1/verified-attributes/query (no dedicated GET /v1/proofs/{id} endpoint in v2 API). |
| Name | Type | Req | Description |
|---|---|---|---|
| chainId | number | – | EVM chain ID where the proof was verified, if applicable. |
| circuitId | string | – | Circuit ID this proof was generated against. |
| docHash | string | – | Document hash this proof attests to. |
| status | string | – | Verification status enum: 'received' | 'verified' | 'onchain-verified' | 'rejected'. Use the SDK's isVerified() helper (or check status === 'verified' || status === 'onchain-verified') for cryptograp… |
No examples provided.
lemma_get_schema ~133
Retrieve a Lemma schema by its ID via GET /v1/schemas/{id}. A schema declares how documents of a given type are interpreted and normalized. Returns SchemaMeta { id, description? } with additionalProperties open — implementations commonly include a `normalize` artifact (WASM that maps raw documents to canonical form) and its content hash. Use this when you need to interpret attribute keys returned by lemma_query_verified_attributes.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Schema ID. Returned in the `schema` field of VerifiedAttributesQueryResponseItem from lemma_query_verified_attributes, or registered via POST /v1/schemas. |
| Name | Type | Req | Description |
|---|---|---|---|
| description | string | – | Human-readable description of the schema. |
| id | string | yes | Schema ID, echoing the request. |
| normalize | object | yes | Normalize artifact — WASM that maps raw documents to canonical form. |
No examples provided.
lemma_query_verified_attributes ~244
Query cryptographically verified attributes from Lemma. Use this as the primary tool for finding documents whose attributes match given conditions (e.g., "subject's birthYear lt 2008"). Returns { results: Array<{ docHash, schema, issuerId, subjectId, attributes, isVerified, proof?: { status, circuitId, chainId }, disclosure? }>, hasMore }. The MCP layer enriches each item with an `isVerified` flag derived from `proof.status` (true when status is 'verified' or 'onchain-verified'). Use lemma_get_proof_status to monitor a specific proof; use lemma_get_schema to interpret the keys returned in `attributes`.
| Name | Type | Req | Description |
|---|---|---|---|
| attributes | array | – | Attribute predicates to AND-combine. |
| chainIds | array | – | Restrict results to attributes verified on these chain IDs (EVM). |
| limit | number | – | Max results per page (1–200). Defaults to API server default (50). |
| offset | number | – | Pagination offset. Pair with `hasMore` in the response to walk pages. |
| schemas | array | – | Restrict results to documents conforming to these schema IDs. |
| Name | Type | Req | Description |
|---|---|---|---|
| hasMore | boolean | yes | True when more results exist beyond this page; pair with `offset` to walk pages. |
| results | array | yes | Result set; each item has been MCP-enriched with `isVerified`. |
No examples provided.
How do I install the io.github.lemmaoracle/mcp server?
io.github.lemmaoracle/mcp is a hosted endpoint at https://mcp.lemma.workers.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.lemma.workers.dev
claude mcp add --transport http lemmaoracle-mcp 'https://mcp.lemma.workers.dev/mcp'
What is the io.github.lemmaoracle/mcp server?
io.github.lemmaoracle/mcp is listed in the public MCP registry as io.github.lemmaoracle/mcp. Verifiable provenance for AI agents, ZK proofs over confidential documents, no plaintext exposure. This page covers its hosted endpoint (https://mcp.lemma.workers.dev/mcp).
Is the io.github.lemmaoracle/mcp server safe to use?
io.github.lemmaoracle/mcp scores 80 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 io.github.lemmaoracle/mcp server expose?
io.github.lemmaoracle/mcp exposes 5 tools: lemma_query_verified_attributes, lemma_get_schema, lemma_get_circuit, lemma_get_generator, lemma_get_proof_status. Their descriptions and schemas cost roughly 949 tokens of context every time the server is loaded.
Does the io.github.lemmaoracle/mcp server require authentication?
No. We connected to io.github.lemmaoracle/mcp without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the io.github.lemmaoracle/mcp server still maintained?
io.github.lemmaoracle/mcp is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.