@cyanheads/treasury-fiscaldata-mcp-server

Public Hosted Server: https://treasury-fiscaldata.caseyjhand.com/mcp

Overview

US Treasury Fiscal Data — national debt, interest rates, exchange rates, and other fiscal datasets. Browse a curated catalog of 17 endpoints, query any endpoint directly, or stage large pulls as DuckDB dataframes for SQL analysis, from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

Related MCP server: @cyanheads/eia-energy-mcp-server

Capability reference

treasury_list_datasets tool

• Filter by category (debt, interest_rates, exchange_rates, revenue_spending, savings_bonds, securities, other) or keyword search.

• Returns endpoint paths, fields, types, and update cadence from a bundled catalog, with no network call.

treasury_query_dataset tool

• Query an endpoint with { field, operator, value } filters (eq, gt, gte, lt, lte, in), sort, and pagination: page_size 1–10000 (default 100), page_number starts at 1.

• Returns rows, field labels, total_count, and total_pages; error reasons are invalid_endpoint, invalid_field, invalid_filter, and page_out_of_range.

• Pass canvas_id to stage the page for SQL analysis; the returned canvas_id is the assigned table name.

treasury_get_debt tool

• mode=latest returns the newest business-day record; mode=date accepts a YYYY-MM-DD date; mode=series accepts a date range. Coverage begins 1993-04-01.

• Returns debt totals and a 20-row series preview; compare retrieved_records with total_records. A missing date returns no_data_for_date.

• Series staging starts above 500 rows or on request via canvas_id; paging stops at 50,000 rows.

treasury_get_interest_rates tool

• mode=latest returns the newest month's rates, optionally filtered by security_type; mode=series accepts a date range.

• Rates are percentages, with available security types disclosed when a filter matches nothing; the series preview holds at most 20 rows.

• Series staging starts above 200 rows or on request via canvas_id.

treasury_get_exchange_rates tool

• Quarterly official reporting rates in foreign currency units per 1 USD. Filter countries by exact name; mode=latest returns one current row per currency and mode=series accepts a date range.

• Each row carries record_date and effective_date; mixed_record_dates flags a result spanning quarters. Series previews hold 20 rows; retrieved_records discloses progress against total_records.

• Series staging starts above 500 rows or on request via canvas_id; paging stops at 50,000 rows.

• country_not_found error when a requested country has no records

treasury_dataframe_describe tool

• Omit name to list the tenant's active dataframes, or supply one exact table name.

• Returns provenance, created/expiry timestamps, row count, and column schema; truncated / max_rows disclose a capped source pull.

• Table expiry defaults to 24h after staging, configurable with CANVAS_TTL_MS.

treasury_dataframe_query tool

• Accepts one read-only SELECT; row_limit defaults to 1000 (max 10000) and preview may not exceed it. System catalogs, external-file functions, and SQL mutations are denied.

• Returns rows and row_count_capped; errors distinguish canvas_unavailable, system_catalog_access, invalid_sql, missing_table, and invalid_query_bounds.

• register_as materializes the full result as a new dataframe with a fresh TTL.

treasury_dataframe_drop tool

• Accepts the exact name from treasury_dataframe_describe, a data tool's canvas_id, or query's registered_as; deletes that table and its provenance for the tenant.

• Returns name and dropped: true; an absent or expired table returns missing_table with guidance to list active tables.

• Disabled by default. Set TREASURY_DATAFRAME_DROP_ENABLED=true and CANVAS_PROVIDER_TYPE=duckdb to make it callable; the HTTP landing page shows the disabled tool and enable hint otherwise.

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

Fiscal Data-specific:

• All API values are strings; "null" means no value. Treasury dataframe columns are VARCHAR — CAST to DECIMAL or DATE for arithmetic and date comparisons. DataCanvas requires CANVAS_PROVIDER_TYPE=duckdb; configured canvas tools report canvas_unavailable otherwise.

• Curated catalog of 17 endpoints with field metadata — no discovery round-trip required; pass any endpoint path directly to treasury_query_dataset for datasets outside the catalog

• Convenience tools for the three most-queried datasets — national debt, interest rates, exchange rates

• DataCanvas integration: large pulls register as df_<id> dataframes queryable via DuckDB SQL, with automatic staging thresholds per tool

• No API key required — the US Treasury Fiscal Data API is free and public

Agent-friendly output:

• Provenance: filter-expression echo (applied_filters) and field-label maps (field_labels) let agents verify what was sent and read raw field names

• Enrichment notices: empty-result guidance, partial-country mismatches, canvas staging confirmations, and truncated-series warnings all name the next tool call

• Graceful truncation: series and query results carry truncated / retrieved_records / row_count_capped fields instead of silently dropping rows

• Canvas provenance: source tool, original query parameters, row count, and column schema surfaced by treasury_dataframe_describe

Getting started

Public Hosted Instance

A public instance is available at https://treasury-fiscaldata.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:

{
  "mcpServers": {
    "treasury-fiscaldata-mcp-server": {
      "type": "streamable-http",
      "url": "https://treasury-fiscaldata.caseyjhand.com/mcp"
    }
  }
}

Self-Hosted / Local

Add the following to your MCP client configuration file.

{
  "mcpServers": {
    "treasury-fiscaldata-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/treasury-fiscaldata-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "treasury-fiscaldata-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/treasury-fiscaldata-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "treasury-fiscaldata-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "ghcr.io/cyanheads/treasury-fiscaldata-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

DataCanvas SQL workflow

For large time-series pulls or multi-dataset analysis, use the DataCanvas SQL workflow:

1. Set CANVAS_PROVIDER_TYPE=duckdb in your server environment.

2. Call a data tool with a canvas_id — e.g., treasury_get_debt with mode=series and a canvas_id value, or treasury_query_dataset with canvas_id. The tool registers the results as a df_XXXXX_XXXXX dataframe and returns the table name.

3. Inspect the schema with treasury_dataframe_describe — lists column names, types (all VARCHAR for Treasury data), row count, and TTL.

4. Query with SQL via treasury_dataframe_query — standard DuckDB SELECT with joins, aggregates, window functions, and CTEs. CAST VARCHAR columns to DECIMAL or DATE for arithmetic.

-- Example: debt trend over the last year, month-end records only
SELECT
  record_date,
  CAST(tot_pub_debt_out_amt AS DECIMAL) / 1e12 AS total_debt_trillions
FROM df_xxxxx
WHERE CAST(record_date AS DATE) >= CURRENT_DATE - INTERVAL 1 YEAR
ORDER BY record_date DESC

Prerequisites

• Bun v1.4.0 or higher (or Node.js v24+).

• No API key required — the US Treasury Fiscal Data API is free and public.

• For DataCanvas SQL: CANVAS_PROVIDER_TYPE=duckdb (DuckDB is bundled as @duckdb/node-api).

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/treasury-fiscaldata-mcp-server.git

2. Navigate into the directory:

cd treasury-fiscaldata-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env as needed — no required vars; CANVAS_PROVIDER_TYPE=duckdb to enable SQL

Configuration

See .env.example for the full list of optional overrides.

Running the server

Local development

• Build and run:

  bun run rebuild
  
  bun run start:stdio
  # or
  bun run start:http

• Run checks and tests:

  bun run devcheck         # Lint, format, typecheck, security
  bun run test             # Vitest test suite
  bun run lint:mcp         # Validate MCP definitions against spec
  bun run lint:deps        # Detect unused and missing dependencies with Knip
  bun run verify:catalog   # Probe every catalog endpoint and field against the live API

  verify:catalog makes live Fiscal Data requests and runs separately from devcheck and the test suite. Run it after editing src/services/fiscal-data/datasets.ts and before a release.

  Builds type-check and emit declarations with TypeScript, then use Bun to bundle server code as Node-compatible ESM in dist/index.js. Package dependencies remain external, including the framework and DuckDB native bindings. The installed server runs on Node or Bun; building from source requires Bun. Dependency checks use knip.jsonc to cover source, scripts, and tests.

Docker

docker build -t treasury-fiscaldata-mcp-server .
docker run --rm -e CANVAS_PROVIDER_TYPE=duckdb -p 3010:3010 treasury-fiscaldata-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/treasury-fiscaldata-mcp-server. A native build-host dependency stage cross-installs DuckDB bindings for the target architecture, preserves the release-age and security checks, and removes unused musl bindings. OpenTelemetry peers are installed at the framework's declared ranges — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Development guide

See CLAUDE.md and AGENTS.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic

• Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage

• All Treasury API values are strings — validate and CAST in downstream SQL; never fabricate missing fields

• Register new tools via the arrays in src/index.ts

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.