CartrouteChangelog
API and product changes, newest first. Breaking API changes ship under a new dated API version; the current version is 2026-09-01.
MCP protocol 2025-11-25 support
The MCP server now negotiates protocol versions 2025-11-25, 2025-06-18, 2025-03-26 and 2024-11-05, and publishes a server card at /.well-known/mcp.json.
API version 2026-09-01
Added requires_eligibility on coupons; student and education offers are no longer subtracted from effective_price_usd. Added price_insight.high_90d_usd.
Micro Center and Staples coverage
Two retailers added, bringing coverage to 12. Micro Center offers are pickup-only and report delivery_days_min as null.
Agent self-registration
POST /api/v1/accounts lets an agent create an account for its user and receive a key with 100 credits. Requires accept_terms: true.
Idempotency keys
Send Idempotency-Key on any metered call; repeats within 24 hours replay the first response without charging.
Coupon success rates
Every coupon now carries success_rate, sample_size and last_verified_at from redemption checks.
Every page as JSON
Product, category, retailer, coupon and guide pages return JSON with Accept: application/json or ?format=json.
Public launch
Search across 10 US retailers with landed and effective price. REST API with OpenAPI 3.1 description.