DataContractGate
NPM · @NIGHTMOOSE/CONTRACTGATE-MCP-SERVER
Infer, dry-run, deploy, and inspect DataContractGate semantic data contracts.
Available components
Last scanned (3 hours ago)
Scores higher than 93% of npm servers
Category Testing and QA
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security100
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- No install/post-install scripts declared.Pass
- 0 of 3 dependencies flagged as unhealthy. View diagnostics → Pass
Provenance & Transparency100
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to nightmoose/contractgate). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 3 days ago).Pass
- Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability85
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 618 tokens (~103/item across 6 items; 6 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management57
- Stability observed for 17 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage98
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 95% 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
- All 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (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.
- 16 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Oct 26 +51
- Injection markers: unverified → pass ▲ security
- Known CVEs: unverified → pass ▲ security
- Stability: unverified → 0.47 ▲ functional
- Schema quality: unverified → 100 ▲ functional
- Tool coverage: unverified → 100 ▲ functional
- MCP protocol: unverified → pass ▲ functional
- Dependency health: unverified → 1.00 ▲ functional
- Package version: 0.3.0 → 0.4.0 functional
- 13 Oct 26 −50
- Known CVEs: pass → unverified ▼ security
- Stability: 0.40 → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Dependency health: 1.00 → unverified ▼ functional
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Schema quality: 100 → unverified ▼ functional
- Package version: 0.3.0 → 0.4.0 functional
- Package version: 0.3.0 → 0.3.2 functional
- Package version: 0.3.0 → 0.3.1 functional
- 12 Oct 26 +16
- Provenance: fail → pass ▲ security
- The attested source repository moved: nightmoose/contractgate security
- Stability: unverified → 0.40 ▲ functional
- Package version: 0.2.0 → 0.3.0 functional
- 1 Oct 26 +15
- Malware scan: unverified → pass ▲ security
- 30 Sept 26 58
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 17 Oct 2026 · Analysed npm/@nightmoose/contractgate-mcp-server@0.4.0
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | npm |
| Reason | Verified |
| Discovered via | Registry attestation endpoint |
| Source repo | nightmoose/contractgate |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/nightmoose/contractgate/.github/workflows/release.yml@refs/tags/v0.4.0 |
| Rekor log index | 3245397630 |
| Predicate type | SLSA build provenance https://slsa.dev/provenance/v1 |
| Subject digest | sha512:36f35336d121d90d26ec3cc5cb823c860d1e0f9889c8bf3a2a7636ac87a5fd4b0a662531768f59edb17c2f49ac92ea805418288125892aba48167c22a |
Background: How many MCP packages publish verified provenance →
Dependencies 3 packages
| Packages resolved | 3 |
|---|---|
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
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 →
deploy_contract Deploy a contract to stable ~118
POST /contracts/deploy — find-or-create by name, insert YAML as stable, deprecate prior stable. 409 if that (name, version) exists: bump version in the YAML. Refused while quarantine is pending. Save the returned contract_id.
| Name | Type | Req | Description |
|---|---|---|---|
| deployed_by | string | – | Actor recorded on the version row |
| name | string | yes | Contract name matching the YAML name: field |
| source | string | – | Logical feed name, e.g. app-backend |
| yaml_content | string | yes | Full contract YAML |
No output schema declared.
No examples provided.
egress_validate Validate an outbound payload ~174
POST /egress/{contract_id}. Validates an outbound payload against a deployed contract. dry_run defaults true — no audit row or quarantine. Returns the full response body (200/207/422) so you can read violations and repair the payload. Forward response.payload only — never the original body after a block or fail.
| Name | Type | Req | Description |
|---|---|---|---|
| contract_id | string | yes | Deployed contract UUID |
| disposition | string | – | Default block. block = drop failing records from payload; fail = reject entire batch; tag = pass through with flags. |
| dry_run | boolean | – | Default true. Set false only after a successful dry run — live calls write audit and quarantine rows. |
| events | array | yes | Outbound payload objects to validate |
| version | string | – | Pin a specific contract version. Default: latest stable. |
No output schema declared.
No examples provided.
get_quarantine List quarantined events ~63
GET /quarantine — rejected events for the caller's org, newest first, with violation details.
| Name | Type | Req | Description |
|---|---|---|---|
| contract_id | string | – | Restrict to one contract |
| limit | integer | – | Default 100, max 500 |
| offset | integer | – | – |
No output schema declared.
No examples provided.
infer_contract Infer a contract from sample events ~91
Generate draft DataContractGate YAML from real JSON sample events via POST /contracts/infer. Does not persist. Review and write the YAML to contracts/<name>.yaml before deploying.
| Name | Type | Req | Description |
|---|---|---|---|
| description | string | – | Optional contract description |
| name | string | yes | Contract name, snake_case, e.g. user_events |
| samples | array | yes | 1–20 real event objects. Do not invent them. |
No output schema declared.
No examples provided.
list_contracts List contracts ~20
GET /contracts — identities the API key can see.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
validate_events Validate events against a contract ~152
Validate events. Pass contract_id to hit POST /v1/ingest/{id} (dry_run defaults true — no audit, quarantine, or usage). Pass yaml_content to hit POST /playground/validate per event (never persists). Exactly one of contract_id or yaml_content. 207/422 responses are returned as data so you can apply each violation's suggestion.
| Name | Type | Req | Description |
|---|---|---|---|
| contract_id | string | – | Deployed contract UUID from deploy_contract |
| dry_run | boolean | – | Ingest only. Default true. Set false only after a successful dry run. |
| events | array | yes | Event objects to validate |
| yaml_content | string | – | In-flight contract YAML; uses the playground, never persists |
No output schema declared.
No examples provided.
How do I install the DataContractGate MCP server?
DataContractGate runs locally as an npm package, launched with npx -y @nightmoose/contractgate-mcp-server. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · @nightmoose/contractgate-mcp-server
claude mcp add nightmoose-contractgate -- npx -y @nightmoose/contractgate-mcp-server
What is the DataContractGate MCP server?
DataContractGate is an MCP server listed in the public MCP registry as io.github.nightmoose/contractgate. Infer, dry-run, deploy, and inspect DataContractGate semantic data contracts. This page covers its npm package (@nightmoose/contractgate-mcp-server).
Is the DataContractGate MCP server safe to use?
DataContractGate scores 91 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 17 October 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. 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 DataContractGate MCP server expose?
DataContractGate exposes 6 tools: infer_contract, validate_events, deploy_contract, get_quarantine, list_contracts, egress_validate. Their descriptions and schemas cost roughly 618 tokens of context every time the server is loaded.
Is the DataContractGate MCP server still maintained?
DataContractGate is still listed as active in the MCP registry. We last reached this channel on 17 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What licence is the DataContractGate MCP server under?
DataContractGate declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.