# Bureau of Transportation Statistics > The Bureau of Transportation Statistics (BTS) is the U.S. Department of Transportation's > federal statistical agency for commercial aviation, multimodal freight activity and > transportation economics. It publishes three public API surfaces, all free, all read-only, > all requiring no credential: an open-data portal at data.bts.gov (Socrata SODA 2.1, OData > 4.0 and a DCAT-US catalog), a geospatial catalog at geodata.bts.gov (OGC API - Records and > Features, backed by 1,079 ArcGIS FeatureServers of the National Transportation Atlas > Database), and the TranStats aviation database at transtats.bts.gov (HTML query forms > only, no machine-readable contract). This file was generated by API Evangelist on 2026-09-05 from the provider's own published surfaces. BTS does not publish an llms.txt of its own (/llms.txt returns 404 on data.bts.gov, geodata.bts.gov and www.transtats.bts.gov). ## Start here - [BTS Data Inventory](https://data.bts.gov/): the open-data portal, 418 datasets, browse and query - [Geospatial at BTS](https://geodata.bts.gov/): the NTAD geospatial catalog, 142 datasets - [TranStats](https://www.transtats.bts.gov/): airline on-time performance and aviation tables - [Get a free app token](https://data.bts.gov/profile/edit/developer_settings): optional; lifts anonymous throttling - [SODA API documentation](https://dev.socrata.com/docs/endpoints.html): the platform reference BTS's portal links ## APIs - BTS Open Data SODA API — base https://data.bts.gov/resource/ — query any dataset by its four-by-four id with SoQL: `GET /resource/{datasetId}.json?$select=&$where=&$order=&$limit=`. Also .csv and .geojson. Default $limit 1000, maximum 50000. - BTS Open Data Metadata API — `GET /api/views/{datasetId}.json` for one dataset's columns and metadata, `GET /api/catalog/v1?q=&domains=data.bts.gov` to search the catalog. - BTS Open Data OData v4 API — `GET /api/odata/v4/{datasetId}`; the service CSDL is at https://data.bts.gov/api/odata/v4/$metadata and declares 184 entity sets. - BTS Geospatial Search API — base https://geodata.bts.gov/api/search/v1 — OGC API - Records. `GET /collections`, `GET /collections/{collectionId}/items`, `GET /conformance`. - TranStats — https://www.transtats.bts.gov/ — web query forms and file downloads only. ## Specs - [Geospatial Search API OpenAPI 3.0 (first-party, verbatim)](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/openapi/bureau-of-transportation-statistics-geodata-search-openapi.json) - [Live copy of the same]( https://geodata.bts.gov/api/search/definition/?f=json) - [OData 4.0 CSDL/EDMX, 184 entity sets (verbatim)](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/odata/bureau-of-transportation-statistics-odata-metadata.xml) - [OGC API conformance document (verbatim)](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/conformance/bureau-of-transportation-statistics-geodata-conformance.json) - [SODA Resource API OpenAPI](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/openapi/bureau-of-transportation-statistics-resource-api-openapi.yml) - [SODA Metadata API OpenAPI](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/openapi/bureau-of-transportation-statistics-metadata-api-openapi.yml) ## Catalogs - [DCAT-US 1.1 catalog, 418 datasets](https://data.bts.gov/data.json) - [DCAT RDF/XML](https://data.bts.gov/api/dcat.rdf) - [NTAD geospatial DCAT-US 1.1, 142 datasets](https://geodata.bts.gov/api/feed/dcat-us/1.1.json) - [Dataset change feed (RSS, dated)](https://data.bts.gov/catalog.rss) - [BTS datasets on data.gov](https://catalog.data.gov/dataset?organization=dot-gov&q=bts) ## How to call it correctly - [Authentication](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/authentication/bureau-of-transportation-statistics-authentication.yml) — optional X-App-Token header - [Conventions](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/conventions/bureau-of-transportation-statistics-conventions.yml) — paging, SoQL, tracing, caching - [Errors](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/errors/bureau-of-transportation-statistics-problem-types.yml) — the Socrata envelope, two shapes - [Rate limits](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/rate-limits/bureau-of-transportation-statistics-rate-limits.yml) — no published number, 429 on exhaustion - [Plans](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/plans/bureau-of-transportation-statistics-plans-pricing.yml) — none; the API is free - [Lifecycle](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/lifecycle/bureau-of-transportation-statistics-lifecycle.yml) — versioning and the missing deprecation policy - [Conformance](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/conformance/bureau-of-transportation-statistics-conformance.yml) — OGC, OData, DCAT-US, SODA - [Agent skills](https://raw.githubusercontent.com/api-evangelist/bureau-of-transportation-statistics/refs/heads/main/skills/_index.yml) ## Notes for agents - Everything is a GET. There is nothing to create, update or delete, so there is no idempotency, no dry-run and no reversal to worry about. - Always pass $order when paging a SODA dataset, or rows can repeat or be skipped. - Data is a U.S. Government Work: https://www.usa.gov/government-works — no copyright, free reuse. - BTS publishes no MCP server and no A2A agent card. A third-party MCP server exists on npm (@pipeworx/mcp-bts) and is not affiliated with BTS. - www.bts.gov is behind an Akamai edge that returns 403 to non-browser clients; the API hosts data.bts.gov and geodata.bts.gov do not block.