Screen Sanctions

Instructions

Implementation Reference

• src/tools/sanctions.ts:31-87 (registration)

  Registration of the 'screen_sanctions' tool on the MCP server, including inputSchema (name, address, threshold) and the async handler that calls the API endpoint /api/v1/sanctions/screen.

  server.registerTool(
    "screen_sanctions",
    {
      title: "Screen Sanctions",
      description:
        "Screen an address, name, or entity against global sanctions lists (OFAC SDN, EU, " +
        "UN, UK). Returns matching entries with match scores. " +
        "Cost: $0.005 per query. Source: Consolidated sanctions lists, updated daily.",
      inputSchema: {
        name: z
          .string()
          .optional()
          .describe("Name or alias to screen"),
        address: z
          .string()
          .optional()
          .describe("Crypto address to screen"),
        threshold: z
          .number()
          .min(0)
          .max(1)
          .optional()
          .describe("Minimum match score (0-1, default 0.8)"),
      },
    },
    async ({ name, address, threshold }) => {
      const res = await apiGet<SanctionsQueryResponse>(
        "/api/v1/sanctions/screen",
        {
          name,
          address,
          threshold: threshold ?? 0.8,
        },
      );
  
      if (!res.ok) {
        return {
          content: [
            {
              type: "text" as const,
              text: `API error (${res.status}): ${JSON.stringify(res.data)}`,
            },
          ],
          isError: true,
        };
      }
  
      const { count, data } = res.data;
      const warn = stalenessWarning(res);
      const summary = `${warn}Found ${count} sanctions match(es).`;
      const json = JSON.stringify(data, null, 2);
  
      return {
        content: [{ type: "text" as const, text: `${summary}\n\n${json}` }],
      };
    },
  );

• src/tools/sanctions.ts:56-86 (handler)

  Handler function for screen_sanctions. Calls apiGet to /api/v1/sanctions/screen with name, address, and threshold params, then formats the response as text content with match count and JSON data.

  async ({ name, address, threshold }) => {
    const res = await apiGet<SanctionsQueryResponse>(
      "/api/v1/sanctions/screen",
      {
        name,
        address,
        threshold: threshold ?? 0.8,
      },
    );
  
    if (!res.ok) {
      return {
        content: [
          {
            type: "text" as const,
            text: `API error (${res.status}): ${JSON.stringify(res.data)}`,
          },
        ],
        isError: true,
      };
    }
  
    const { count, data } = res.data;
    const warn = stalenessWarning(res);
    const summary = `${warn}Found ${count} sanctions match(es).`;
    const json = JSON.stringify(data, null, 2);
  
    return {
      content: [{ type: "text" as const, text: `${summary}\n\n${json}` }],
    };
  },

• src/tools/sanctions.ts:39-54 (schema)

  Input schema for screen_sanctions: optional name (string), optional address (string), optional threshold (number 0-1, default 0.8).

  inputSchema: {
    name: z
      .string()
      .optional()
      .describe("Name or alias to screen"),
    address: z
      .string()
      .optional()
      .describe("Crypto address to screen"),
    threshold: z
      .number()
      .min(0)
      .max(1)
      .optional()
      .describe("Minimum match score (0-1, default 0.8)"),
  },

• src/client.ts:44-76 (helper)

  The apiGet helper function used by the handler to make GET requests to the Verilex API.

  export async function apiGet<T = unknown>(
    path: string,
    params?: Record<string, string | number | undefined>,
  ): Promise<ApiResponse<T>> {
    const url = buildUrl(path, params);
  
    const headers: Record<string, string> = {
      Accept: "application/json",
      "User-Agent": "verilex-mcp-server/0.1.0",
    };
  
    // Forward x402 payment token if present in env (for paid endpoints)
    const paymentToken = process.env.VERILEX_PAYMENT_TOKEN;
    if (paymentToken) {
      headers["X-Payment-Token"] = paymentToken;
    }
  
    const res = await fetch(url, { headers });
    const data = (await res.json()) as T;
  
    const stale = res.headers.get("X-Data-Stale");
    const lastUpdated = res.headers.get("X-Data-Last-Updated");
    const ageSeconds = res.headers.get("X-Data-Age-Seconds");
  
    return {
      ok: res.ok,
      status: res.status,
      data,
      stale: stale === "true",
      lastUpdated: lastUpdated ?? undefined,
      ageSeconds: ageSeconds ? Number(ageSeconds) : undefined,
    };
  }

• src/client.ts:35-41 (helper)

  The stalenessWarning helper function used by the handler to add a staleness warning if data is stale.

  export function stalenessWarning(res: ApiResponse): string {
    if (!res.stale) return "";
    const parts = ["[STALE DATA]"];
    if (res.lastUpdated) parts.push(`Last updated: ${res.lastUpdated}`);
    if (res.ageSeconds != null) parts.push(`Age: ${res.ageSeconds}s`);
    return parts.join(" ") + "\n\n";
  }