iwant.fyi demand-side protocol
The iwant.fyi demand-side protocol defines how AI agents express structured purchase intent on behalf of users, receive matched supply across multiple sources, and report outcomes back. It is MCP-native, transport-flexible, and intentionally agnostic about who matches the demand, who fulfills it, and how money moves.
Why
Existing agentic commerce protocols are supply-side: ACP and UCP define how an agent completes a purchase at a merchant; AP2 handles payment authorization; MCP is general tool/data access. None of them defines how an agent expresses what its user wants in a structured, machine-matchable form, or how that demand persists across sessions and gets fulfilled across multiple sources.
The iwant.fyi demand-side protocol fills that gap.
Spec
- v1.1 (Draft) — Current. Additive, backward-compatible with v1.0: signed webhooks for
Standing Wants (§16), partial-result transparency (§6.1), retryable error taxonomy (§11.2), idempotency keys (§8.4), capability discovery (§8.2), deterministic ordering + cursor (§6.3).
Read it rendered with anchors at iwant.fyi/protocol/v1.
JSON Schema for the core objects: schemas/1.1/ (also served live at https://iwant.fyi/.well-known/iwantfyi/schemas/1.1/).
Conformance
A test kit verifies any implementation against spec §15:
npx @iwantfyi/conformance-kit --mcp https://iwant.fyi/api/mcp --http https://iwant.fyi/api/v1 --api-key <key>Source: conformance-kit/ · npm: @iwantfyi/conformance-kit (Apache-2.0). The reference implementation also self-reports at /api/v1/conformance.
Reference implementation
iwant.fyi — https://iwant.fyi/api/mcp
The iwant.fyi MCP server is the reference implementation. It advertises spec conformance and is the canonical surface to test against.
Official SDKs (all Apache 2.0)
| Framework | Package | Repo | |---|---|---| | TypeScript / generic | @iwantfyi/sdk | staugs/iwantfyi-sdk | | LangChain (Python) | iwantfyi-langchain | staugs/iwantfyi-langchain | | Composio (Python) | iwantfyi-composio | staugs/iwantfyi-composio | | CrewAI (Python) | iwantfyi-crewai | staugs/iwantfyi-crewai |
Three open-source example agents at staugs/iwantfyi-examples.
Status
v1.1 is published as a draft for public comment. Feedback, issues, and proposed extensions are welcome via GitHub issues or directly to hi@iwant.fyi.
License
The specification is published under the Apache License 2.0. Implementations are not required to be open source.
