Send GET https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/debt/mspd/mspd_table_1 to retrieve the summary of Treasury securities outstanding by category
Filter by fiscal year and month with params: filters[record_date:gte]=YYYY-MM-01 and filters[record_date:lte]=YYYY-MM-DD
Request only the fields you need: fields=record_date,security_type_desc,avg_interest_rate_amt,outstanding_amt to reduce payload size
Retrieve the interest rates breakdown from the separate endpoint: GET .../v2/accounting/od/avg_interest_rates to get average interest rates by security type and class
Cross-reference table 1 outstanding amounts with the avg_interest_rates dataset by matching security_type_desc to compute implied annual interest cost
Export as CSV by appending format=csv to the query string for loading into spreadsheet or BI tools
Known gotchas
Table numbering in the MSPD series (mspd_table_1, mspd_table_2, etc.) does not map directly to the PDF table numbers in the published statement — verify field descriptions in the API metadata endpoint
MSPD data is published on the fourth business day of each month for the prior month-end; polling earlier will return the previous month's data with no indication that it is stale
The outstanding_amt field represents billions of dollars in some tables and millions in others depending on the table; always check the units field in the dataset metadata
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp