AR
Arc & Ledger Tax Data API
U.S. tax reference: federal tax parameters, filing deadlines, IRC 6621 interest rates, and IRS notice and form profiles
11 operations4 schemas1 revision
Changes
Full historySource
View schema- Spec
- OpenAPI 3.0.3
- Document
- api.arcandledger.com · JSON, 6 KB
- Retrieved
- Oct 19, 2026, 17:43 UTC
- Digest
- d435ea185ef3
For agents
Every page here has a markdown twin. The overview is one fetch; the llms.txt lists every operation with a link to its own markdown.
curl https://skmtc.dev/arcandledger/apis/arc-ledger-tax-data-api.mdcurl https://skmtc.dev/arcandledger/apis/arc-ledger-tax-data-api/llms.txt