mcp server
mcp
Verifiable provenance for AI agents — ZK proofs over confidential documents, no plaintext exposure.
Description as published by the maintainer. Source
- version 0.0.17
- active
- document understanding
active — Registry entry last updated 2026-05-18. Dashed tags are derived by ZBS Index from the published description, not stated by the maintainer.
What this server can do
5 functions, named and described by the server itself. Parameter names are shown because they say more about what a function does than its name usually does.
lemma_get_circuit(circuitId)- 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. Required: circuitId.
lemma_get_generator(generatorId)- 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. Required: generatorId.
lemma_get_proof_status(verificationId)- 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. Required: verificationId.
lemma_get_schema(id)- 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. Required: id.
lemma_query_verified_attributes(limit, offset, schemas, chainIds, attributes)- 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`.
Last successful function declaration observed on . Source: https://mcp.lemma.workers.dev/mcp. We list what the server declared; we do not call any of these functions.
Endpoint status observed on . Source: https://mcp.lemma.workers.dev/mcp.
Signals
These are separate measurements of different things. They are deliberately not combined into one score, because a popularity number that mixes website traffic with saves and stars cannot be checked or acted on.
| Signal | Value | What it measures | Window | Observed | Source |
|---|---|---|---|---|---|
| Latest published version | 0.0.17 | Latest version string the maintainer published to the registry. | as of fetch | Model Context Protocol | |
| Registry record last updated | 2026-05-18 | When the registry record was last updated by its maintainer. | point in time | Model Context Protocol | |
| First listed in the MCP Registry | 2026-05-18 | Date this server was first published to the official MCP Registry. Not a usage or quality measure. | point in time | Model Context Protocol | |
| mcp tools declared | 5 tools | Number of functions the server itself declared when asked to list them. This is what the server offers an agent, not a measure of how well any of them work. | as of probe | mcp.lemma.workers.dev | |
| mcp endpoint status | ok | The server listed 5 functions when asked. | as of probe | mcp.lemma.workers.dev |
Where to get it
This record as data
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GET /api/v1/entries/mcp_server.json