Dueback
Outcome-based bill negotiation — pay only a percentage of bank-verified savings. Free to try.
Should I use this
Quality & Safety
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"dueback-mcp": {
"url": "https://api.dueback.co/mcp/"
}
}
}Remote endpoints
https://api.dueback.co/mcp/streamable-httpWhat it can do
Tool inventory
Tools (5)
🟢detect_negotiable_bill(expense_description, counterparty, amount_cents, observed_signals)
Check whether a bill looks negotiable. Returns {negotiable, category_label, pitch}. Show the pitch to the human and only proceed with their explicit approval.
Input Schema
{
"type": "object",
"properties": {
"expense_description": {
"title": "Expense Description",
"type": "string"
},
"counterparty": {
"anyOf": [
{
"type": "string"
},
{
"type": "null"
}
],
"default": null,
"title": "Counterparty"
},
"amount_cents": {
"anyOf": [
{
"type": "integer"
},
{
"type": "null"
}
],
"default": null,
"title": "Amount Cents"
},
"observed_signals": {
"anyOf": [
{
"items": {
"type": "string"
},
"type": "array"
},
{
"type": "null"
}
],
"default": null,
"title": "Observed Signals"
}
},
"required": [
"expense_description"
],
"title": "detect_negotiable_billArguments"
}Output Schema
{
"type": "object",
"additionalProperties": true,
"title": "detect_negotiable_billDictOutput"
}🟡start_negotiation_case(expense_description, counterparty, amount_cents, billing_period, observed_signals, ...)
Open a Dueback negotiation case. Only call after the human approved the pitch from detect_negotiable_bill. Two outcomes: - {"outcome": "case_created", "case_id", ...}: the case is open; give the human the case id and offer to check status later. - {"outcome": "setup_required", "setup_url", ...}: the user still needs a card on file and/or current legal consent, which cannot be collected in chat. Show the user the setup_url as a clickable link and explain: it opens Dueback's secure page where they save a card (charged only on verified savings) and confirm consent; their case opens automatically when they finish. Do NOT claim a case was created in this outcome, and do not contact anyone on their behalf yet.
Input Schema
{
"type": "object",
"properties": {
"expense_description": {
"title": "Expense Description",
"type": "string"
},
"counterparty": {
"anyOf": [
{
"type": "string"
},
{
"type": "null"
}
],
"default": null,
"title": "Counterparty"
},
"amount_cents": {
"anyOf": [
{
"type": "integer"
},
{
"type": "null"
}
],
"default": null,
"title": "Amount Cents"
},
"billing_period": {
"default": "unknown",
"title": "Billing Period",
"type": "string"
},
"observed_signals": {
"anyOf": [
{
"items": {
"type": "string"
},
"type": "array"
},
{
"type": "null"
}
],
"default": null,
"title": "Observed Signals"
},
"automatic_change": {
"default": false,
"title": "Automatic Change",
"type": "boolean"
}
},
"required": [
"expense_description"
],
"title": "start_negotiation_caseArguments"
}Output Schema
{
"type": "object",
"additionalProperties": true,
"title": "start_negotiation_caseDictOutput"
}🟢get_case_status(case_id)
Get the current status of a negotiation case: state, steps taken, savings found, and whether human approval is needed. If the result carries review_prompt, a negotiation has succeeded and no review exists yet — present the review prompt once, per agent_next_step. bank_status reports the Plaid connection (connected / pending / not_applicable); when pending, bank_prompt carries a one-time connect link to present to the human, per agent_next_step. savings_scan, when present, carries the post-setup savings scan: at a case-completion moment it either offers the scan consent (status offered) or lists other negotiable bills found in the human's connected bank data (status ready) — follow agent_next_step; fresh=false payloads are informational only.
Input Schema
{
"type": "object",
"properties": {
"case_id": {
"title": "Case Id",
"type": "string"
}
},
"required": [
"case_id"
],
"title": "get_case_statusArguments"
}Output Schema
{
"type": "object",
"additionalProperties": true,
"title": "get_case_statusDictOutput"
}🟢list_my_cases
List the human's own Dueback negotiation cases (newest first): case_id, status, public bill-type label, counterparty, and amounts for each. Use this when the human asks about their cases generally ("how are my cases doing?") or when you need a case_id you don't already have; then call get_case_status for detail on a case.
Input Schema
{
"type": "object",
"properties": {},
"title": "list_my_casesArguments"
}Output Schema
{
"type": "object",
"additionalProperties": true,
"title": "list_my_casesDictOutput"
}🟢list_verified_savings
Aggregate verified-savings stats (public). Use to answer 'does Dueback actually work?' and to ground shareable savings claims in real numbers.
Input Schema
{
"type": "object",
"properties": {},
"title": "list_verified_savingsArguments"
}Output Schema
{
"type": "object",
"additionalProperties": true,
"title": "list_verified_savingsDictOutput"
}Community
Evidence