PennyGems API integration & OpenData services

Protocol analysis, watchlist extraction, and ratings-history APIs for PennyGems: Screen Penny Stocks (StockRing, Inc.)

From $300 · Pay-per-call available
OpenData · OpenFinance · Protocol analysis · Market data ingestion

Turn PennyGems watchlists, Grab/Buy/Sell ratings, and stock metadata into a queryable data layer

PennyGems screens roughly 2,000 US penny stocks under $10 and publishes Grab, Buy, Hold, Sell, and Dump recommendations three times a day during market hours. That pipeline produces structured data — ratings, ticker metadata, intraday sparklines, fundamentals, and AI-curated news — that portfolio tools, compliance systems, and quant stacks can ingest if access is properly authorized and mapped. We build that mapping for you.

Watchlist extraction API — Pull a user's personalized watchlist, sort keys (daily gain, volume, volatility), and color-coded sparkline series for downstream dashboards.
Ratings history API — Access the Grab / Buy / Hold / Sell / Dump rating timeline across days, weeks, and months to validate signal accuracy and feed backtesting engines.
Ticker detail bundle — Fundamentals (EPS, revenue, debt, dividends), technicals (moving averages, volatility), company profile, and earnings-date calendar in one normalized payload.
News & story feed — AI-curated story stream per ticker, mapped to publisher, timestamp, and sentiment hooks for compliance logging or investor-relations tools.

Feature modules we build

Authenticated session mirror

We reverse engineer the PennyGems mobile authentication flow (device registration, token issuance, session refresh) and expose it as a typed server-side client. A downstream portfolio service can mint a session on behalf of an authorized user and reuse it for watchlist and ratings calls without forcing the user back into the app. Typical use: a broker's research portal that needs to surface a client's saved penny-stock picks inside its own dashboard.

Rating-change webhooks

Because PennyGems updates its Buy/Sell calls three times per trading session, batch polling wastes bandwidth. We wrap the refresh endpoint as a normalized webhook: every transition (for example Hold → Buy on ticker SNDL) is pushed as a JSON event with timestamps, previous rating, and confidence hints. Typical use: alerting an in-house trading Slack, or gating swing-trade entry rules.

Watchlist sync bridge

The watchlist holds ticker, sort preference, alert triggers, and daily performance snapshots. We mirror it into your system of record (Postgres, BigQuery, or a SaaS CRM) with conflict-safe upserts. Typical use: unifying a retail trader's PennyGems watchlist with their TradeStation or Interactive Brokers positions for a single blended PnL view.

Ratings-history backtester feed

A distinctive PennyGems feature is the multi-month history of its own ratings — users can audit how accurate past Buy calls turned out. We expose that time series as a flat CSV / Parquet feed indexed by (ticker, rating_date, rating_tier) so quant teams can regress it against actual price action or combine it with Alpha Vantage / Finnhub price history.

News story ingestion

The in-app news stream is AI-curated from dozens of business publishers. We normalize each item to {ticker, headline, publisher, published_at, canonical_url, summary}. Typical use: feeding an internal research wiki, or deduplicating stories already ingested from a Bloomberg or Reuters feed.

Export & reporting module

Any of the above data can be packaged into Excel, JSON, or PDF exports on a schedule. Typical use: month-end compliance archives, or investor-relations snapshots that log every rating change on a basket of micro-cap holdings. Outputs are tagged with source, retrieval time, and hash so downstream auditors can verify lineage.

Data available for integration

The table below lists the structured data PennyGems produces, mapped to the in-app surface where it originates. This is the inventory we typically normalize into OpenData-style endpoints.

Data typeSource (app surface)GranularityTypical downstream use
Rating tier (Grab / Buy / Hold / Sell / Dump)Stock detail & rating cardPer ticker, ~3× per trading dayAlerting, signal validation, backtesting
Rating historyHistory tab on any tickerPer ticker, daily/weekly/monthlyAccuracy audits, quant features, compliance archive
Watchlist membership & sort orderPersonal watchlist screenPer user, per tickerCross-platform watchlist sync, CRM enrichment
Price quote, daily range, % change, market capWatchlist rowsPer ticker, intradayDashboard widgets, risk limits, mid-day summaries
Sparkline seriesWatchlist & ticker cardIntraday, typically 1–5 min bucketsThumbnail charts in internal tools
Fundamentals (EPS, revenue, debt, dividends)Metrics tabPer ticker, refreshed around earningsScreening, peer comparison, research notes
Technicals (moving averages, volatility)Metrics tabPer ticker, dailyEntry/exit rules, volatility filters
Company profile & business descriptionProfile tabPer ticker, static-ishResearch summaries, onboarding copy
News stories (AI-curated)Top Stories feedPer ticker, continuousSentiment ingest, compliance logging
Search index (company name / ticker)Global search~1,200–2,000 US penny tickersAutocomplete, universe definition

Typical integration scenarios

1. Signal-to-execution bridge for a swing-trading desk

Context: A small swing-trading shop uses PennyGems as an idea generator and TradeStation or Interactive Brokers for execution.

Data / API involved: Ratings webhook for Grab/Buy transitions; watchlist sync for ticker allowlists; ticker detail bundle for pre-trade volatility and float checks.

OpenFinance mapping: PennyGems acts as the "signal producer"; the brokerage API (or a pay-per-call gateway we host) acts as the executor. Events flow signal → risk filter → order staging. Every rating change is persisted with source hash so post-trade compliance can trace the idea origin.

2. Retail wealth-app watchlist unification

Context: A consumer wealth app wants to let users import their PennyGems watchlist alongside holdings from Robinhood or a broker connected via Plaid-style aggregation.

Data / API involved: Authenticated session mirror, watchlist extraction API, ratings history for each imported ticker.

OpenData mapping: The integration looks like a classic OpenData feed — user authorizes, consent is logged, a read-only token is issued, and watchlist + ratings flow into the wealth app's canonical portfolio schema. No trading permissions are requested.

3. Quant research pipeline for micro-cap alpha

Context: A quant team wants to test whether PennyGems rating transitions have predictive power on next-day returns for stocks under $10.

Data / API involved: Ratings-history backtester feed (Parquet), ticker metadata, joined against Alpha Vantage or Financial Modeling Prep price history.

OpenFinance mapping: Outputs land in the team's research lake; downstream Jupyter notebooks compute information coefficients. We provide a stable schema and replay endpoint so the feature is reproducible across model retrains.

4. Investor-relations monitoring for micro-cap issuers

Context: An IR firm representing OTC / micro-cap issuers wants to track when PennyGems changes its rating on client tickers and what news stories the app is surfacing.

Data / API involved: Ratings webhook filtered by a ticker basket, news story ingestion, export module for weekly PDF reports.

OpenData mapping: Read-only ingest into the IR firm's existing media-monitoring stack. Each captured story includes canonical publisher URL so it can be cross-referenced against SEC EDGAR XBRL filings and FINRA OTC Transparency data for a fuller picture.

5. Educational & paper-trading platforms

Context: A trading-education product wants students to paper-trade against the same rating stream retail users see.

Data / API involved: Real-time ratings feed, ticker search, daily snapshot export for grading.

OpenFinance mapping: The education platform becomes a secondary consumer of PennyGems signals under a documented data-use agreement; we handle rate-limit shaping and user-level attribution so the source can validate traffic.

Technical implementation

Auth & session bootstrap

POST /api/v1/pennygems/session
Content-Type: application/json

{
  "device_id": "dev-9f2c...",
  "app_version": "com.stockring.cheapstocks/2025.x",
  "auth": { "type": "user_consent_token", "value": "<USER_TOKEN>" }
}

200 OK
{
  "session_id": "sess_7h2k...",
  "expires_at": "2026-04-23T20:15:00Z",
  "scopes": ["watchlist:read", "ratings:read", "news:read"]
}

Watchlist + ratings fetch

GET /api/v1/pennygems/watchlist?sort=gain_desc
Authorization: Bearer <SESSION_ID>

200 OK
{
  "items": [
    {
      "ticker": "SNDL",
      "rating": "BUY",
      "rating_changed_at": "2026-04-23T14:02:00Z",
      "price": 1.84,
      "pct_change": 3.95,
      "volume": 21450000,
      "sparkline": [1.77,1.78,1.81,1.83,1.84],
      "market_cap_usd": 482000000
    }
  ],
  "paging": { "cursor": null }
}

Rating-change webhook

POST https://your-app.example/hooks/pennygems
X-PennyGems-Signature: t=1714060000,v1=9a...

{
  "event": "rating.changed",
  "ticker": "MARA",
  "previous": "HOLD",
  "current":  "BUY",
  "rated_at": "2026-04-23T18:30:00Z",
  "source":   "pennygems.mobile.v1",
  "trace_id": "01HV7..."
}

Signature validation uses HMAC-SHA256 over the raw body with a per-tenant secret. Replay protection via t timestamp window (default 5 min).

Ratings history export (CSV / Parquet)

GET /api/v1/pennygems/ratings/history
  ?ticker=SNDL
  &from=2025-01-01
  &to=2026-04-23
  &format=parquet
Authorization: Bearer <SESSION_ID>

# Columns:
# ticker, rated_at, rating_tier, previous_tier,
# intraday_slot (1|2|3), source_hash

Errors follow a stable shape: { "error": { "code": "rate_limited", "message": "...", "retry_after": 12 } }. Clients can back off on 429 and reconcile missed webhooks through the history endpoint; no state is lost.

Compliance & privacy

PennyGems ships with a clear disclaimer: it is not trading advice and StockRing, Inc. disclaims liability for inaccurate or incomplete signals. Any integration we build preserves that disclaimer in-band — every rating payload carries a disclaimer_ref pointer so downstream UIs cannot strip it. Beyond that, penny-stock data touches several real regulatory surfaces:

  • SEC EDGAR & Regulation Best Interest: When rating signals are re-displayed to US retail users, disclosures must remain visible. The SEC EDGAR APIs (submissions and XBRL financial facts) are the canonical truth source we cross-reference when surfacing company fundamentals.
  • FINRA OTC Transparency: Many penny tickers trade OTC. Where volume or last-sale data is needed, we route through the FINRA OTC Transparency Data API rather than scraping quotes.
  • GDPR / CCPA: Personal data (watchlist ownership, device IDs) is handled under consent-based processing, with deletion endpoints and retention limits documented per tenant.
  • Data minimization: We only extract the fields a given use case actually needs; requests for whole-user dumps are declined.
  • Authorization only: We work under customer authorization or documented public/authorized APIs — no bypass of login, paywall, or anti-abuse controls.

Data flow & architecture

A minimal pipeline for most PennyGems integrations looks like this:

  1. Client app / authorized session — a consented user or a service account with a documented scope.
  2. Ingestion gateway — our normalized API layer that mirrors watchlist, ratings, news, and fundamentals endpoints.
  3. Storage & deduplication — append-only store (Postgres, BigQuery, or S3 + Parquet) keyed by (ticker, rated_at) or (user_id, ticker).
  4. Consumers — dashboards, webhook subscribers, quant notebooks, scheduled Excel / PDF exports.

Each stage emits structured logs with a shared trace_id, so a single rating event can be followed from the source refresh through to the Slack alert or broker order ticket that eventually acted on it.

Market positioning & user profile

PennyGems is developed by StockRing, Inc. and distributed across Google Play, the App Store, and the Amazon Appstore, with specific callouts for Google Pixel, Samsung Galaxy S / Note / Tab, and Wear OS — indicating a primarily US, Android-heavy retail audience. Typical users are day traders, swing traders, scalpers, and longer-term micro-cap investors who want triaged Buy/Sell calls on stocks under $10 rather than building their own screeners. Pricing is freemium with a Premium tier commonly cited at about $10/month or $100/year and a one-week free trial, so the user base skews toward self-directed retail traders rather than institutional desks. For integration work, that shapes the realistic scope: watchlists are small (tens of tickers per user), rating events are moderate frequency (three refreshes per trading day across ~2,000 tickers), and the highest-value data is the rating-history time series that is hard to reconstruct elsewhere.

Screenshots

Click any thumbnail to view a larger version.

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Similar apps & integration landscape

Teams working with PennyGems often also evaluate or integrate the following tools. We frame each purely as part of the micro-cap / retail-trading data ecosystem — different apps produce different slices of the same user's workflow, and unified integrations tend to deliver the most value.

  • VectorVest — a stock analysis app with its own proprietary rating system. Users who consult VectorVest's rating alongside PennyGems often want both signals aligned on a single ticker timeline; a unified integration avoids manual reconciliation.
  • Finviz (and Finviz Elite) — a browser-based screener with extensive export and API capability, including Excel, Python, and Google Sheets recipes. Pairing Finviz screens with PennyGems ratings gives a two-stage funnel: broad screen, then opinionated triage.
  • Penny Stocks Screener: Screens — an iOS-focused penny-stock screener with more than a hundred criteria. Teams that ingest its filter presets often combine them with PennyGems rating labels to seed starter watchlists.
  • Penny Stocks Screener: AI Scan — another App Store entry in the category. Its AI-derived signals are conceptually close to PennyGems Grab/Buy tiers, so cross-checking them is a common quant use case.
  • Penny Stocks - Stocks Alert (Sagamill) — a Google Play alerts-focused app. Integrations often dedupe its alerts against PennyGems rating changes to suppress redundant notifications.
  • Alpha Vantage — a free stock API in JSON and CSV covering realtime and historical prices, options, forex, and 50+ technical indicators. The natural price-data counterpart to PennyGems' rating signal.
  • Finnhub — real-time quotes, company fundamentals, estimates, and alternative data. Frequently joined against PennyGems rating events to compute forward returns.
  • Financial Modeling Prep (FMP) — fundamentals, CIK lookup, and SEC filing mapping. Useful when PennyGems fundamentals need to be cross-validated against primary filings.
  • Marketstack / Twelve Data / EODHD — broad market-data APIs that cover 30,000+ tickers including SEC filings and screener endpoints. Common upstream choices when PennyGems coverage (US penny tickers) must be extended to wider universes.
  • TradeStation, Interactive Brokers, and Robinhood — execution venues frequently mentioned alongside penny-stock workflows. Integrations typically treat PennyGems as the idea source and these as the execution endpoint, with a compliance log in between.
  • SEC EDGAR & FINRA OTC Transparency APIs — regulatory data sources that anchor any serious OTC / micro-cap pipeline. We recommend routing fundamentals and OTC volume questions through these rather than scraping the consumer app.

What we deliver

Deliverables checklist

  • OpenAPI / Swagger specification of the normalized PennyGems endpoints
  • Protocol and authentication report (session lifecycle, token refresh, anti-abuse signals)
  • Runnable source for watchlist, ratings, ratings-history, and news endpoints (Python or Node.js)
  • Webhook sample with HMAC verification middleware
  • Excel / CSV / Parquet export templates
  • Integration test suite and sample fixtures
  • Compliance notes: disclaimer propagation, retention, consent logging

Engagement models

  • Source-code delivery from $300 — ready-to-run API source and documentation; pay after delivery upon satisfaction.
  • Pay-per-call hosted API — call our managed endpoints and pay only for what you use; no upfront commitment, ideal for early-stage products.
  • Retainer — monthly retainer for teams that need ongoing schema updates as PennyGems evolves.

About our studio

We are an independent technical studio focused on app-interface integration, authorized API integration, and OpenData / OpenFinance delivery for global clients. Our engineers come from fintech backends, mobile reverse engineering, and data-pipeline work; we have shipped production integrations for banking, brokerage, e-commerce, travel, and social apps. For PennyGems specifically, our edge is understanding both the micro-cap data domain and the mobile session model that produces it — we can move from "can this be integrated?" to a compliant, documented API without the client having to do the reverse engineering themselves.

  • Protocol analysis, session modelling, and token lifecycle design
  • OpenAPI-first delivery with typed Python / Node.js / Go clients
  • Cloud hosting patterns (webhook fan-out, schedulers, Parquet lakes)
  • Security reviews, consent logging, and retention policies
  • Transparent pricing: source code delivery from $300, or pay-per-call hosted API

Contact

Share the target app and your integration requirements and we will scope it within one to two business days.

Contact page

Typical response time: under 24 hours on business days. NDA available on request.

Engagement workflow

  1. Scope confirmation — which endpoints (watchlist, ratings, news), which export formats, and which compliance surface.
  2. Protocol analysis and API design (typically 2–5 business days).
  3. Implementation and internal validation (typically 3–8 business days).
  4. Documentation, OpenAPI spec, sample clients, and test cases (1–2 business days).
  5. First delivery in about 5–15 business days; edge cases and third-party approvals can extend timing.

FAQ

What do you need from me to start?

The target app (PennyGems is already specified), the exact data you want to extract or mirror, any existing sandbox or authorized account, and your downstream stack (so we pick matching client libraries).

How long does a first drop usually take?

For PennyGems-scale integrations, expect 5–12 business days for the first runnable API plus documentation.

How do you handle the app's disclaimer?

The disclaimer that PennyGems is not trading or investing advice is preserved in-band on every rating payload, and we document how downstream UIs should surface it.

Do you support pay-per-call pricing?

Yes. If you prefer not to own the source code, you can call our hosted endpoints and pay per successful call.
📱 Original app overview (appendix)

PennyGems: Screen Penny Stocks (package com.stockring.cheapstocks) is a penny-stock screener and tracker published by StockRing, Inc. It is available on Google Play, the Apple App Store (as "PennyGems: Scan Penny Stocks"), and the Amazon Appstore, with device coverage including Google Pixel, Samsung Galaxy S / Note / Tab, and Wear OS.

The app covers roughly 2,000 US penny stocks trading under $10 and lets users search, scan, and follow them in personalized watchlists. Each stock receives a five-tier rating — Grab (Super Buy), Buy, Hold, Sell, and Dump (Super Sell) — updated during market hours, and users can review the history of those ratings across days, weeks, and months to audit their accuracy.

  • Stock ratings: Grab / Buy / Hold / Sell / Dump, with rating history per ticker and filters to show only Grab or Buy names.
  • Watchlist: Add tickers with Buy ratings, sort by daily gain, trading volume, or volatility; view price quotes, daily range, dollar/percent change, market cap, and color-coded sparklines.
  • Charts & details: Tap any ticker for price charts across weeks, months, and multi-year windows; Profile, Metrics, and History tabs cover company description, fundamentals (dividends, debt, income, revenue, EPS), technicals (moving averages, volatility), and earnings dates.
  • Business news: AI-curated Top Stories per ticker from dozens of business publications, formatted for Android phones and tablets.
  • Device reach: Works across Android phones, tablets, and Wear OS; iOS version available under the same StockRing developer account.
  • Target users: Day traders, swing traders, scalpers, and long-term micro-cap investors seeking triaged Buy/Sell calls.
  • Pricing (as commonly reported): Free tier plus a Premium subscription around $10/month or $100/year, with a one-week free trial.

Disclaimer (as stated in the app): PennyGems is not intended to be trading or investing advice. Always do your own due diligence using multiple sources of information, and consult a licensed professional before trading or investing. StockRing, Inc., its officers, directors, investors, and contractors disclaim liability to the maximum extent permitted by law for any commentary, analysis, information, opinions, advice, or recommendations that prove inaccurate, incomplete, or unreliable, or that result in any investment or other losses.