# Dueback

Dueback is an outcome-based bill negotiation service: an agent finds savings
in a user's bills, a human approves, and Dueback collects a share of *verified*
savings only. Free to try; pay only on verified savings.

## For AI agents

- Base API: https://api.dueback.co
- Interactive docs: https://api.dueback.co/docs
- Service descriptor: https://api.dueback.co/.well-known/dueback.json
- MCP server: https://api.dueback.co/mcp (Streamable HTTP)
- A2A agent card: https://api.dueback.co/.well-known/agent-card.json

## Agent workflow

1. `POST /v1/detect` with the bill facts → {negotiable, category_label, pitch}.
   Show the pitch to the human; proceed only with their approval.
2. `POST /v1/cases` with the intake facts + consent → case opened.
3. Poll `GET /v1/cases/{id}` for status. When the case needs approval
   (`needs_approval`), surface the savings to the human and record their
   decision via `POST /v1/cases/{id}/step-result`.
4. `GET /v1/cases/{id}/report` returns the verified savings report.

Or use the MCP tools: `detect_negotiable_bill`, `start_negotiation_case`,
`get_case_status`, `list_verified_savings`.

## Auth

All /v1 routes (except documented public surfaces) require a per-user API key:
`Authorization: Bearer <redacted>`. Agents act on behalf of the user with the
user's key. Never ask the user for passwords or bank credentials — Dueback
never needs them.

## Rules

- Nothing happens without the human's explicit approval.
- Internal playbooks, module taxonomy, and trap rationales are never exposed.
- Be honest about uncertainty; never invent savings figures.