MCP servers for AI agents

Two Model Context Protocol servers put both chains in front of an agent. @odatano/core-mcp reads Cardano, queries the indexer with OData, builds unsigned transactions and submits signed CBOR. @odatano/nightgate-mcp anchors documents on Midnight, proves zero-knowledge claims over hidden fields and verifies against live contract state. Both carry the ASTRA analytics for their chain.

Both make the same promise: the agent gets a notary, not a wallet. Nothing in either server can sign. HSM signing, wallet sessions, contract deployment and every admin operation are not exposed. On Cardano a human or a CIP-30 wallet signs. On Midnight the agent builds locally and a sponsor pays, or a scoped grant limits what a session may do.

Set-up

One oda_… key from the API page configures both servers. Needs Node.js 20 or newer; npx fetches the servers.

{
  "mcpServers": {
    "odatano": {
      "command": "npx",
      "args": ["-y", "@odatano/core-mcp"],
      "env": { "ODATANO_ACCESS_KEY": "oda_..." }
    },
    "nightgate": {
      "command": "npx",
      "args": ["-y", "@odatano/nightgate-mcp"],
      "env": { "ODATANO_ACCESS_KEY": "oda_..." }
    }
  }
}

With Claude Code:

claude mcp add odatano   --env ODATANO_ACCESS_KEY=oda_... -- npx -y @odatano/core-mcp
claude mcp add nightgate --env ODATANO_ACCESS_KEY=oda_... -- npx -y @odatano/nightgate-mcp

The hosted gateway is the default URL. It swaps in the agent grant underneath, meters the key per call and answers a 402 with the top-up hint when units run out.

Shared configuration

Variable	Default	Purpose
`ODATANO_ACCESS_KEY`		the `oda_…` key. Against a direct instance: an `odat_…` or `ngat_…` agent grant, or any other bearer
`ODATANO_ACCESS_URL`	`https://api.preprod.odatano.dev`	the gateway, or your own instance, e.g. `http://localhost:4004`
`ODATANO_ACCESS_USER`, `ODATANO_ACCESS_PASSWORD`		basic auth against a dev instance with CAP mocked auth
`ODATANO_ANALYTICS_URL`	`<ODATANO_ACCESS_URL>/odata/v4/astra`	where ASTRA answers; the `analytics_*` tools register when it does

Per-server variables (timeouts, row caps, service prefixes, the wallet-job opt-in, the local builder seed) are in the READMEs linked below.

ODATANO-MCP (Cardano)

The tool catalogue follows the host. The hosted API and every ODATANO 1.x host get the core tools. A self-hosted 2.0 host adds status tools for crawler and wallet worker; ODATANO_MCP_ENABLE_WALLET_JOBS=1 adds the two job tools where a server wallet signs.

Group	Tools	What
Read	`get_network_info`, `get_latest_block`, `get_block`, `get_epoch`, `get_protocol_parameters`, `get_transaction`, `get_transaction_metadata`, `parse_transaction_cbor`, `get_address`, `get_utxos`, `get_address_assets`, `get_address_transactions`, `get_asset_info`, `get_asset_history`, `get_account`, `get_pool`, `get_drep`	chain, address, asset, staking and governance lookups. A miss returns `{ found: false }`, never an error
Query	`query_entity`	OData V4 over every entity set: `$filter`, `$select`, `$expand`, `$orderby`, `$top`, `$skip`, `$count`. Questions no fixed action covers become one call
Build	`build_ada_transfer`, `build_metadata_transaction`, `build_multi_asset_transfer`, `build_mint_transaction`, `build_plutus_spend`, `set_collateral`, `get_build_details`, `list_builds_by_address`, `derive_script_address`, `extract_payment_key_hash`	every build returns `{ id, unsignedTxCbor, fee }`. Nothing is signed
Sign and submit	`create_signing_request`, `get_signing_request`, `list_signing_requests`, `verify_signature`, `verify_data_signature`, `submit_signed_transaction`, `submit_verified_transaction`, `get_submission_status`	hand-off to a human or wallet, verification, submission of signed CBOR
Analytics	`analytics_overview`, `analytics_key_figures`, `analytics_daily`, `analytics_top`, `analytics_epochs`, `analytics_metrics`, `analytics_metric`, `analytics_series`, `analytics_compare`, `analytics_anomalies`	ASTRA for Cardano, one unit a read
2.0 host only	`get_sync_status`, `get_reorg_log`, `get_worker_status`, `get_wallet_job_status`, `submit_wallet_job`, `cancel_wallet_job`	crawler and wallet worker; the last two are opt-in and move funds

A typical flow:

get_network_info → get_utxos(address) → build_ada_transfer(...)   nothing moved
parse_transaction_cbor                                            show the human what they sign
create_signing_request                                            instructions + cardano-cli command
… human or CIP-30 wallet signs …
verify_signature → submit_signed_transaction → get_submission_status

NIGHTGATE-MCP (Midnight)

Twenty-two tools cover the attestation surface: verify, prove, anchor, grant, sponsoring and jobs. Write tools return a job id; get_job_status polls until succeeded or failed. Every verify tool answers verified: false when nothing is there, never an error.

Group	Tools	What
Verify	`verify_attestation`, `verify_predicate`, `verify_predicate_attestation`, `verify_document`	live contract state, no wallet, no crawler. Anyone can call them
Prove	`prepare_document_proof`, `prepare_membership_set`, `prove_field_predicate`, `prove_field_equality`, `prove_field_membership`, `prove_field_predicates_batch`, `prove_document_integrity`, `prove_document_diff`	canonicalise a document, then prove a threshold, an equality, a membership or a cross-document claim. Values stay hidden. Up to 8 claims in one transaction
Anchor	`anchor_document`, `attest_agent_output`	a content hash on chain under the session’s attester id; agent-output provenance
Grant	`grant_disclosure`, `revoke_disclosure`	who reads which tier of an anchored document. Attester only
Sponsoring	`build_sponsorable_transaction`, `get_attester_identity`, `sponsor_unbound_transaction`, `sponsor_finalized_transaction`, `derive_token_type`	build, prove and sign locally with `NIGHTGATE_SEED_HEX`, a sponsor pays the dust. Needs `@odatano/nightgate-tx` next to the server
Jobs	`get_job_status`	poll an async job
Analytics	`analytics_overview`, `analytics_key_figures`, `analytics_daily`, `analytics_top_block_producers`, `analytics_metrics`, `analytics_metric`, `analytics_series`, `analytics_compare`, `analytics_anomalies`	ASTRA for Midnight, one unit a read

Session-bound writes (anchor_document, prove_*, grant_disclosure) need a wallet session, which is created outside MCP by design. Through the hosted gateway the agent writes via the sponsoring tools instead: the platform pool pays.

A typical flow through the gateway, with NIGHTGATE_SEED_HEX set:

get_attester_identity            → attesterId the server builds under
prepare_document_proof           → payloadHash, contentRoot, per-field inputs
build_sponsorable_transaction    → bytes for "anchorContentRoot"        (local, 20 to 60 s)
sponsor_unbound_transaction      → { jobId, sessionId }                (platform pool pays)
get_job_status                   → succeeded
build_sponsorable_transaction    → "proveFieldPredicate", e.g. carbon_footprint ≤ 80
sponsor_unbound_transaction → get_job_status → verify_predicate → verified: true

The MCP version must match the NIGHTGATE server it talks to. The compatibility table on GitHub pairs them.

Your own instance

Set ODATANO_ACCESS_URL to your ODATANO or NIGHTGATE host. For a local cds watch with mocked auth, ODATANO_ACCESS_USER=alice is enough. For anything else, create a scoped agent grant once as the operator and hand the returned odat_… or ngat_… token to the agent as ODATANO_ACCESS_KEY. The write tools are then limited to the grant’s allow list, budget and pinned session.

The Docker images are the fastest way to an own instance: ghcr.io/odatano/odatano and ghcr.io/odatano/nightgate. See ODATANO and NIGHTGATE.

Errors

Upstream errors reach the agent as { httpStatus, code, message }, so it can react instead of failing blind: 401 means credentials, 400 means fix the arguments, 429 means back off, 402 means top up. A Midnight job that fails with CHAIN_EXECUTION_FAILED landed on chain but did not apply; build again against current state, never resubmit the same bytes.

On GitHub

ODATANO-CORE-MCP: every tool with its arguments, configuration, integration check · npm
NIGHTGATE-MCP: tools, sponsoring set-up, compatibility table · npm
NIGHTGATE TX: the local builder behind build_sponsorable_transaction
ASTRA: what the analytics_* tools return