# legal_fetch_patent_by_number

Fetch full patent details by patent number and jurisdiction. Read-only. No side effects. Idempotent. patent_number: Patent number in EPODOC format e.g. EP1000000 for European, CN120586032 for Chinese, JP2020123456 for Japanese, WO2020123456 for PCT, US10000000 for US. Required. jurisdiction: Optional hint — one of EP, CN, JP, KR, US, WO, etc. Default EP. The tool normalises the patent number automatically; passing CN120586032 with jurisdiction EP is valid. Returns title, abstract, inventors, assignees, filing date, claims summary, and citation count. Use this when you have a specific patent number. Use legal_search_patents_by_keyword instead when you only have keywords and need to find patents. Verified source: EPO OPS. 24-hour cache. If this tool's response does not serve the user's need, call report_feedback with feedback_type="agent_gap", tool_id="legal_fetch_patent_by_number", intended_query="{what the user needed}", gap_description="{what was missing or wrong in the result}".

Agent View of the PolicyLayer registry record for `legal_fetch_patent_by_number`. HTML page: https://policylayer.com/tools/dev-7bd0-mcp-server/legal-fetch-patent-by-number

## Facts

- Tool: `legal_fetch_patent_by_number`
- Server: DataNexus MCP (`dev-7bd0/mcp-server`) — https://policylayer.com/tools/dev-7bd0-mcp-server.md
- Homepage: https://github.com/dev-7bd0/mcp-server
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 2
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `jurisdiction` | string | no | Patent office code: EP, US, WO. Default EP. Optional. |
| `patent_number` | string | no | Patent number e.g. EP3456789 or US10123456. Required. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "legal_fetch_patent_by_number",
    "arguments": {}
  }
}
```

## Why legal_fetch_patent_by_number is rated Low

This is a straightforward data retrieval operation against public patent databases. It queries existing information indexed by patent number and jurisdiction, returning structured patent metadata. No mutation, deletion, execution, or financial operations are possible. The read-only guarantee and idempotency explicitly stated in the description confirm zero side effects.

From the tool's own definition: "Tool description explicitly states 'Read-only. No side effects. Idempotent.' The function fetches and retrieves patent details (title, abstract, inventors, assignees, filing date, claims, citations) without creating, modifying, deleting, or executing anything."

## Use case

AI agents call legal_fetch_patent_by_number to retrieve information from DataNexus MCP without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches DataNexus MCP:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "legal_fetch_patent_by_number": {}
  }
}
```

## Other tools on DataNexus MCP (54)

- `apikeys_revoke_api_key` — Destructive — https://policylayer.com/tools/dev-7bd0-mcp-server/apikeys-revoke-api-key.md
- `apikeys_rotate_api_key` — Destructive — https://policylayer.com/tools/dev-7bd0-mcp-server/apikeys-rotate-api-key.md
- `compliance_check_sam_exclusion` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/compliance-check-sam-exclusion.md
- `compliance_fetch_finra_broker` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/compliance-fetch-finra-broker.md
- `compliance_fetch_npi_provider` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/compliance-fetch-npi-provider.md
- `compliance_search_npi_by_name` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/compliance-search-npi-by-name.md
- `domain_check_email_security` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-check-email-security.md
- `domain_fetch_dns_records` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-dns-records.md
- `domain_fetch_domain_history` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-domain-history.md
- `domain_fetch_domain_rdap` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-domain-rdap.md
- `domain_fetch_reverse_ip` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-reverse-ip.md
- `domain_fetch_ssl_certificate_chain` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-ssl-certificate-chain.md
- `domain_fetch_subdomains` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/domain-fetch-subdomains.md
- `frontend_security_audit_ci_pipeline` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/frontend-security-audit-ci-pipeline.md
- `frontend_security_audit_manifest` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/frontend-security-audit-manifest.md
- `frontend_security_detect_typosquatting` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/frontend-security-detect-typosquatting.md
- `frontend_security_fetch_package_risk_brief` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/frontend-security-fetch-package-risk-brief.md
- `govcon_fetch_open_solicitations` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/govcon-fetch-open-solicitations.md
- `govcon_fetch_vendor_contract_history` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/govcon-fetch-vendor-contract-history.md
- `govcon_search_contract_awards` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/govcon-search-contract-awards.md
- `legal_fetch_inventor_portfolio` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/legal-fetch-inventor-portfolio.md
- `legal_fetch_patent_citations` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/legal-fetch-patent-citations.md
- `legal_search_patents_by_keyword` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/legal-search-patents-by-keyword.md
- `nonprofit_fetch_charity_uk` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-fetch-charity-uk.md
- `nonprofit_fetch_nonprofit_by_ein` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-fetch-nonprofit-by-ein.md
- `nonprofit_fetch_nonprofit_financial_trends` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-fetch-nonprofit-financial-trends.md
- `nonprofit_fetch_nonprofit_full_profile` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-fetch-nonprofit-full-profile.md
- `nonprofit_search_nonprofits_by_category` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-search-nonprofits-by-category.md
- `nonprofit_search_nonprofits_by_name` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/nonprofit-search-nonprofits-by-name.md
- `regulatory_fetch_docket_details` — Read — https://policylayer.com/tools/dev-7bd0-mcp-server/regulatory-fetch-docket-details.md
- …and 24 more: https://policylayer.com/tools/dev-7bd0-mcp-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=dev-7bd0-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-7bd0-mcp-server