# iwant.fyi Demand-Side Protocol HTTP Fallback

**Canonical:** https://apis.io/apis/iwant-fyi/iwantfyi-demand-side-protocol-http-fallback/  
**Provider:** iwant.fyi — https://apis.io/providers/iwant-fyi/  
**Base URL:** https://iwant.fyi/api/v1  
**Documentation:** https://iwant.fyi/protocol/v1

iwant.fyi Demand-Side Protocol HTTP Fallback is one of 4 APIs that [iwant.fyi](https://apis.io/providers/iwant-fyi/) publishes on the [APIs.io](https://apis.io/) network. This API exposes 4 JSON Schema definitions. Tagged areas include Purchase Intent, Matching, and Webhook. The published artifact set on APIs.io includes an API reference and 4 JSON Schemas.

The canonical protocol surface for agents that do not speak MCP — POST /wants, GET /wants/{id}, POST /search, POST /outcomes, GET /verticals, GET /constraints, GET /health, GET /capabilities, GET /conformance and the /watches* and /supply* endpoints under https://iwant.fyi/api/v1 — mirroring the demand.* MCP tools per spec section 9. Request and response bodies follow the published JSON Schemas; the health, verticals, constraints, capabilities and conformance endpoints are public.

## Machine-readable artifacts (7)

- **APIReference** — https://iwant.fyi/protocol/v1
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/json-schema/iwant-fyi-want.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/json-schema/iwant-fyi-match.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/json-schema/iwant-fyi-match-response.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/json-schema/iwant-fyi-outcome.json
- **Webhooks** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/asyncapi/iwant-fyi-webhooks.yml
- **Conformance** — https://raw.githubusercontent.com/api-evangelist/iwant-fyi/refs/heads/main/conformance/iwant-fyi-conformance.yml

## Other iwant.fyi APIs (3)

- [iwant.fyi Agent API](https://apis.io/apis/iwant-fyi/iwantfyi-agent-api/)
- [iwant.fyi MCP Server](https://apis.io/apis/iwant-fyi/iwantfyi-mcp-server/)
- [iwant.fyi A2A Agent](https://apis.io/apis/iwant-fyi/iwantfyi-a2a-agent/)

## Tags

Purchase Intent, Matching, Webhook

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/iwant-fyi/iwantfyi-demand-side-protocol-http-fallback/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/iwant-fyi/.