doctor-of-credit-mcp

People researching bank bonuses, credit-card offers, and other deals published by Doctor of Credit must currently browse and interpret individual articles themselves. The source material contains valuable details: eligibility restrictions, expiration dates, direct-deposit requirements, geographic limits, and update history. But those details are expressed as prose and can change over time. AI clients need a dependable way to discover and retrieve that source material without losing provenance or presenting inferred details as facts.

Run locally

Requires Node.js 22 or newer.

npm install
npm run build
npm start

The process communicates using MCP over stdio. Configure an MCP client to run node /absolute/path/to/doctor-of-credit-mcp/dist/cli.js.

The server currently provides:

• list_categories() retrieves every category from Doctor of Credit's WordPress API.
• get_post(url_or_id) retrieves a post by its positive integer WordPress ID or HTTPS Doctor of Credit article URL.
• get_recent_posts(category?, limit?) retrieves recent posts from WordPress, optionally filtered by a category slug returned by list_categories. The default limit is 10 and the maximum is 100.
• search_posts(query, category?, after?, limit?) searches WordPress article text and titles. category accepts a slug from list_categories, after accepts an ISO calendar date (YYYY-MM-DD) and excludes older publications, and limit defaults to 10 with a maximum of 100.
• compare_offers(post_ids[]) retrieves between 1 and 10 unique posts by positive integer WordPress ID. It returns each article independently under posts and does not merge or infer offer terms. If some posts cannot be retrieved, successful articles remain available and each failure is reported with its requested ID under failures. If every retrieval fails, the tool returns an actionable MCP error without comparison data.
• get_big_deals(limit?) retrieves likely notable deal articles. The default limit is 10 and the maximum is 25.
• find_bank_bonuses(bank?, state?, amount_min?) retrieves up to 10 likely bank-bonus source articles. bank is an institution text signal, state is a two-letter USPS state or District of Columbia code (case-insensitive), and amount_min is a positive whole-dollar threshold up to $1,000,000.
• find_credit_card_offers(issuer?, card?, bonus_min?) retrieves up to 10 likely credit-card source articles. Issuer and card name are source-text signals; bonus_min is a positive integer up to 1,000,000 compared within each source-mentioned unit.

Post tools return source-backed fields under source: the stable ID, original URL, title, publication and modification timestamps, and cleaned article text. Interpretive fields live separately under derived. The server sets derived.outdatedWarning when the article has not been modified for more than 180 days. This conservative threshold uses the only dependable freshness signal available in the source contract—the modification timestamp— and avoids inferring an offer-specific expiration date from prose. It is a prompt to verify the source, not a claim that the offer is valid or expired.

get_recent_posts falls back to the global or category-specific RSS feed when WordPress is unavailable or returns invalid data. RSS items use the same post shape, but RSS does not publish a modification timestamp, so modifiedAt is null for those results. Their outdated warning conservatively uses the publication timestamp instead. The server does not persist retrieved content or metadata.

search_posts uses WordPress search directly so relevance and all filters are applied by the source. It does not fall back to the recent-post RSS feed, because that feed cannot provide a complete or relevance-ranked search result.

get_big_deals applies a deterministic candidate policy to the 100 most recent posts (using the existing RSS fallback when WordPress is unavailable). An article qualifies when its cleaned title or text contains a dollar amount of at least $500 or an amount of at least 50,000 immediately followed by “points” or “miles.” Candidates are ordered by: number of qualifying signal types, largest dollar mention, largest points/miles mention, publication date, then stable post ID, all descending. The matched maxima and qualifying-signal count appear under derived.selectionSignals; they are text-selection signals, not assertions about an offer's value, availability, or validity. Every candidate otherwise retains the shared source and warning contract.

find_bank_bonuses searches up to 100 WordPress results using the supplied institution, the state's full name, and “bank bonus” as search terms. It then keeps only articles whose cleaned title/text contains both “bonus” and a banking term (bank, banking, checking, savings, credit union, or deposit account). Optional filters must also appear in the source text: the institution is matched case-insensitively, geography matches the full state name or uppercase postal code, and the largest dollar mention must meet amount_min. Results are ordered by publication date and stable ID, descending, then capped at 10. Match booleans and the largest dollar mention live under derived.bankBonusSignals; they identify candidate evidence only and do not assert geographic eligibility, direct-deposit requirements, availability, offer value, or current validity. Search failures return errors rather than falling back to an incomplete recent-post feed.

find_credit_card_offers searches up to 100 WordPress results using the supplied issuer, card name, and “credit card offer” as search terms. It keeps only articles whose cleaned title/text contains both a credit-card term and an offer signal (bonus, offer, welcome, or sign-up). Optional issuer and card filters must also occur in the source text. bonus_min matches when either the largest dollar mention or the largest points/miles mention meets the threshold in its own source unit; dollars and rewards are never converted or valued against one another. Results are ordered by publication date and stable ID, descending, then capped at 10. All match booleans and amount mentions live under derived.creditCardOfferSignals; they are candidate evidence only and do not assert eligibility, bonus value, restrictions, availability, or current validity. Search failures return errors rather than incomplete RSS results.

Upstream HTTP, network, and response-validation failures are returned as actionable MCP tool errors rather than empty or fabricated results.

Development

npm run typecheck
npm test

Tests exercise behavior through an MCP client. Most use an in-memory MCP transport with controlled upstream HTTP fixtures; a smoke test launches the compiled stdio entry point.

Planned tools

I’d next add higher-level research tools: Those higher-level tools would search and collect likely articles, but let the connected model interpret restrictions, expiration dates, direct-deposit rules, and similar prose. Results should always include: Original article URL Publication and modification dates Cleaned article text An explicit distinction between source data and AI-derived fields Warnings when an offer may be outdated Internally, it can use the WordPress endpoint first, RSS as a fallback, and a small SQLite cache. No separate public REST service is necessary—the MCP server itself becomes the interface. A TypeScript implementation using the official MCP SDK would make a clean local server that works over stdio, with optional remote HTTP support later.