An AI assistant only gives you useful answers about your money, not generic advice, when it can see two different things: what the market is doing, and what you actually own. Polygon.io is built for the first half. Here's what's possible with a Polygon.io MCP today, and how to add the second half, your real accounts and net worth, decoded into one view your AI can reason about, so your assistant reasons across both. No code, free to start.

If you've ever wired up clean market data and still couldn't ask your AI "given where my portfolio actually sits, what should this move mean for me?", it's not you. Polygon.io's endpoints are organized by ticker. That answer is organized by account, and your accounts sit behind separate logins that a market-data API doesn't reach. This guide covers how to connect Polygon.io to an AI assistant and bring those accounts together with it, so your AI can finally reason about market context and your real position in the same conversation.

1. Create a free Truthifi account. Sign up at truthifi.com — no credit card for the free tier.

2. Link your accounts. Connect brokerage, retirement, bank and card accounts via Plaid, Yodlee, or Morningstar ByAllAccounts. By Truthifi's design, your credentials go to the aggregator rather than to Truthifi.

3. Turn on MCP access. Connecting your own AI assistant via MCP works on every current consumer plan, including free ones.

4. Add Truthifi to your assistant. Add a custom connector with URL https://api.truthifi.com/mcp in your AI assistant's connector settings, and authorize.

5. Turn it on and ask. Toggle Truthifi on and ask: What's my net worth, and am I on track to retire?

What is an MCP?

An MCP, or Model Context Protocol, is an open standard that lets your AI assistant pull live data from a connected source instead of relying on what you type in. Anthropic introduced it, and other companies including OpenAI have since built support for it, so Polygon.io's MCP server works with a growing range of assistants. A "Polygon.io MCP" means a connector that feeds Polygon.io market data to your AI this way. (Truthifi's own connector is described on the Truthifi MCP page.)

Does Polygon.io have an MCP server?

Yes. According to its public GitHub repository, Polygon.io publishes an official MCP server (Polygon.io's official MCP server), and community-built servers exist alongside it. You can connect it to an AI assistant to work with Polygon.io market data, read-only, over MCP. That's the open standard Anthropic introduced and others, including OpenAI, have since adopted. This lets a growing range of AI assistants use the same connector instead of you copy-pasting numbers or uploading exports by hand.

Pairing Polygon.io's market feed with your actual holdings is a different job, and that's where Truthifi fits alongside it: one read-only, decoded view of the accounts you connect that your AI can reason about (see below, or learn more).

What Polygon.io does

Polygon.io is a market-data infrastructure provider. According to Polygon.io's own documentation, its REST and WebSocket APIs deliver real-time and historical financial market data to developers, fintech apps, and AI agents.1 It's designed for:

• Real-time and historical market data: US equities, options, forex, and crypto, via REST and WebSocket. (Getting started)

• Aggregated bars, trades, quotes, and snapshots: OHLCV data across asset classes.

• Fundamentals and corporate data: SEC filings, earnings, dividends, stock splits, and financials.

• Technical indicators: SMA, EMA, MACD, and RSI, available as API endpoints.

• Market news and ticker details: for thousands of symbols.

It runs a freemium model. According to its pricing page (2026), a free tier with limited API calls scales through paid plans to custom enterprise pricing for higher call volumes, real-time WebSocket data, and deeper historical access. Pricing tiers change, so confirm current plan prices on the Polygon.io pricing page.

About Polygon.io: a privately held market-data company serving developers, fintech apps, and institutions.

Good to know about Polygon.io

Four practical questions to settle before you wire Polygon.io into an AI workflow:2

• What does it cost? A free tier exists with limited calls; paid plans scale up for real-time data, higher volumes, and extended history. See pricing.

• What's on the free tier? Limited API calls and delayed data on the entry tier, with real-time WebSocket and the heaviest historical access on paid plans. Check the pricing page for current limits.

• What asset classes are covered? US equities, options, forex, and crypto across REST and WebSocket. (docs)

• Is it for me, or for developers? Polygon.io is a B2B data API: it's the raw market-data engine that powers fintech apps and quant systems, not a personal-finance product.

That gap, between market data and your own financial accounts, is where adding Truthifi to your setup shines.

Polygon.io API: getting your Polygon.io data for AI

Does Polygon.io have an API? Yes, a public market-data API (Polygon.io docs), but it serves market data, not your own account balances and holdings. Truthifi gives your AI assistant read-only, programmatic access to the bank, brokerage and card accounts you connect. Your AI can then reason about your whole financial picture alongside Polygon.io's market data over MCP (the Model Context Protocol). There's no code and no API keys, and by Truthifi's design your credentials go to the aggregator rather than to Truthifi. Your assistant can query balances, holdings, and transactions from the accounts you've connected in one view, read-only by architecture. Connect your accounts to your AI →

How Truthifi can help

Truthifi's job here is narrower than Polygon.io's: it reads only the accounts you choose to connect, not the market. Accounts at any of 18,000+ institutions (per Truthifi platform data, see the source note2) are decoded into clean data from an independent source that earns no commissions, carries no ads, and gives no advice. (See how this compares with other connectors on the financial MCP servers hub. The Alpaca MCP and Plaid MCP guides are close neighbors.) Along the way, Truthifi checks and reconciles figures across the statements it reads, running 130+ automated diagnostics (a self-reported Truthifi figure, 2026), so your AI works from corrected numbers rather than raw feeds. Once that's connected, try questions like these:

• "What's my net worth across my connected accounts right now?"

• "Am I on track to retire, and what's dragging on my returns?"

• "Which of my investments cost the most in fees?"

• "Where am I most concentrated, and is that a risk?"

Here's where the ticker-versus-account split bites in practice. Your script streams options quotes over Polygon.io's WebSocket and pulls earnings from the REST API to flag earnings plays. Every response comes back keyed by ticker symbol, with no field for which of your accounts already holds that ticker. Your 401(k) at Fidelity, Roth IRA at Vanguard, and taxable account at Schwab each answer that only for themselves. So when you ask, "Given everything I actually hold, can I retire at 62?", the screen has nothing to offer. Once those three accounts are connected, the same AI that reads Polygon.io's market data can answer that retirement question directly, using Truthifi's data, refreshed automatically once a day (an on-demand refresh costs 3 credits). Once a second account is linked, look for things that are hard to see across separate logins, such as two funds that hold mostly the same stocks, or a fee that didn't show up as a line on a statement.

Put the two together and most questions get a ticker side and an account side. Polygon.io supplies the price, the indicator, or the filing; Truthifi supplies how much of that ticker you hold and where, decoded from your statements into one read-only view of your connected accounts. Then your AI can answer questions like these:

• "The market dropped 4% today. Given what I actually hold, how much did my net worth move?"

• "Polygon shows my sector is overbought. How concentrated am I in it across my connected accounts?"

• "If I rebalanced toward what the data favors, what would it cost me in fees across my connected accounts?"

To be clear on the division of labor for a Polygon.io setup: Truthifi covers your personal accounts, investments, and net worth, read-only, decoded, cross-institution. Market data, indicators, and feeds for your quant or trading workflow stay in Polygon.io, and you keep using it for exactly that. Truthifi doesn't connect to Polygon.io itself; it sits alongside it as the layer that brings your real financial picture to the same AI.

For more prompts that use your account side, see how to ask your AI about your real investment accounts.

Two ways to start. Run a free portfolio-analysis scan and let Truthifi put your connected accounts in one plain-language scorecard, or connect them to the AI assistant you already use and ask in plain English. Live AI access works on every current consumer plan, including free ones.

Is it safe to connect my accounts to Truthifi?

No online connection is ever completely risk-free, but these protections are built into how the connection works. Your assistant has read-only access to the bank, brokerage and card accounts you connect, it gets a sign-in token rather than your password, and your data is encrypted in transit and at rest. You can revoke access any time under Connections → Agents → Revoke. (See how Truthifi keeps your accounts secure.)

• Read-only by architecture. Truthifi can't move money, place trades, or change a setting. That limit lives in the connection itself, not in a terms-of-service promise.

• Credentials go to the aggregator, not Truthifi (by design). According to Truthifi's documented setup, your login is encrypted in your browser and passed straight to the aggregator (Plaid, Yodlee, or Morningstar ByAllAccounts), which returns a read-only token.

• Requests logged. You get per-tool daily and monthly counts of what each AI assistant accessed, useful for your own oversight.

• Bank-grade encryption in transit and at rest, and you control access per account, revoke it anytime, in your assistant's connector settings or inside Truthifi.

How to connect your accounts to your AI assistant

No command line is needed: the whole setup happens in your browser, on any MCP-capable assistant. (Background on the connector itself is on the Truthifi MCP page.)

• Create a free Truthifi account at truthifi.com, no credit card for the free tier.

• Link your accounts, including your brokerage, retirement, bank, and card accounts, through Truthifi's secure Plaid, Yodlee, or Morningstar ByAllAccounts connection.

• Turn on MCP access. Creating an account and running a portfolio-analysis scan is free, and connecting your own AI assistant via MCP works on every current consumer plan, including free ones. Fee breakdowns, benchmarks and deeper diagnostics are part of paid Monitoring plans ($8.99/mo or $79.99/yr as of October 2026).

• Add Truthifi to your assistant. The same connector URL works across MCP-capable assistants: https://api.truthifi.com/mcp. Inside your assistant's connector settings (usually Settings → Connectors), add a custom connector called Truthifi, paste in the URL, and authorize. (Most assistants require a paid plan for custom connectors. For exact, step-by-step setup for your specific assistant, see the connect guides.)

• Turn it on and ask: "What's my net worth, and how am I tracking toward retirement?"

What you can ask your AI

• "What's my net worth across my connected accounts today?"

• "Is my current savings rate enough to retire on track? Model conservative, moderate, and optimistic cases."

• "Total up the fund fees I'm paying across my connected accounts this year, and show the 10-year cost at 7% growth."

• "Where am I most concentrated, by holding, sector, and single account, and is any of it a risk?"

• "Stress-test my whole portfolio against a 2008-style drop: how far would I fall, and how long to recover?"

• "Find any duplicate or overlapping holdings across my accounts that I didn't realize I had."

• "The market's down sharply this week, how much did my actual net worth move?"

• "If I move $5,000 from savings into investing, what does it do to my net worth over 10 and 20 years?"

With & Without Truthifi

A basic connector gets an account into your AI, and that's genuinely useful on its own. Truthifi is the layer on top, turning those raw feeds into verified, household-level data your AI can reason on.

Dig deeper: track your net worth, hidden investment fees, and retirement readiness.

Common questions about Polygon.io

Is Polygon.io worth it? That depends on whether you need a real-time, programmatic market-data feed. Polygon.io is built for developers, fintech apps and quant systems, and its free tier lets you test before paying. If your real question is "where do I actually stand financially," that's a personal-account view. Adding Truthifi brings your real holdings into your AI alongside the market data.

What do people say about Polygon.io? This isn't a formal survey: in the public developer threads we reviewed (Reddit r/algotrading and GitHub issues, October 2026; see the source note2), the topics that came up most were API coverage, data depth, and the freemium tiers. The free tier's call limits and delayed data come up often, as do trade-offs around historical depth on lower tiers. For seeing your own portfolio rather than the market, a connector like Truthifi is one option.

Are there alternatives to Polygon.io? Other market-data APIs exist. If what you actually want is an AI that sees your whole financial life, your real holdings and net worth rather than just market prices, that's a different tool. A connector like Truthifi sits on top of the accounts you already have, alongside whatever data feed you use.

Why am I hitting rate limits on Polygon.io's free tier? The entry tier caps API calls and serves delayed data; higher-volume and real-time access live on paid plans. Check current limits on the pricing page.

Does Truthifi connect Polygon.io itself? No. Polygon.io is the market-data layer in your setup; Truthifi is the complementary, read-only layer that brings your personal accounts to the same AI. They sit side by side, Truthifi doesn't replace or plug into Polygon.io.

Do I need to write code to set up Truthifi? No. The entire Truthifi setup runs in your browser, no command line, API keys, or config files. (The community Polygon.io MCP servers do involve code; Truthifi does not.)

Which AI assistants does Truthifi work with? In principle, any MCP-capable assistant that supports custom connectors. MCP is an open standard that Anthropic introduced and OpenAI and others have since adopted, so a growing range of assistants can use the same Truthifi connector URL.

Truthifi and the data layer

Polygon.io solved a real, hard problem: getting quotes, aggregates, indicators and SEC filings into motion so other systems can use them. That plumbing works. What it can't hand your AI is your own position, because that lives in statements your institutions write, not in a market feed. Truthifi is the complementary layer that makes that side Decoded, Verified, and yours. Positions are named and fees identified wherever your institutions report them, independently confirmed, and refreshed automatically once a day into one whole-picture foundation your AI can reason over.

A Polygon.io feed is keyed by ticker, while your exposure is keyed by account, and the two rarely line up one-to-one. Polygon.io's ticker details describe the company behind a symbol, not the funds in your accounts that hold it. A 4% move in that stock can still reach you through an index fund in your 401(k) and an ETF in your taxable account, with no position in your name. The market feed doesn't know what you hold, and a single brokerage login doesn't know what your other accounts hold. It takes the pairing to turn a ticker move into a dollar figure for you.

Keep going

• See every connector: the financial MCP servers hub, including the Stripe MCP, Alpaca MCP, and Plaid MCP guides.

• How to ask your AI about your real investment accounts

• How to spot hidden investment fees

• What is Truthifi? and how Truthifi keeps your accounts secure

The short version

The definitive answer: Yes, Polygon.io has an official MCP server, and it gives your AI market data. It can't see your accounts, so add Truthifi if you want your AI to know what you actually hold. Polygon.io powers the market-data layer in your stack. If you want your AI to see your own financial picture too, your real holdings and net worth alongside the market, connect your accounts with Truthifi. Adding it takes about three minutes, free to start and no code. A good first test: pick a ticker you follow on Polygon.io and ask your AI what share of your net worth it represents across your connected accounts. If that number surprises you, your next prompt isn't a market question at all; it's a concentration question about your own accounts. Connect your accounts to your AI →

See every connector on the financial MCP servers hub, or browse all connect guides.

Read next from the Truthifi blog

• What's my net worth?

• What am I paying in fees?

• Am I on track to retire?

About the author

Truthifi Bot drafts these provider guides from Truthifi's data and public sources. Every page is reviewed by the Truthifi Team before publishing.

• "What Polygon.io does", capabilities, asset coverage, and pricing model sourced from Polygon.io's own documentation (polygon.io/docs/stocks/getting-started, polygon.io/pricing) and reviewed October 2026. Founding year, founders, and specific plan prices are cited in secondary press and change frequently, confirm current specifics on polygon.io. ↩

• Category questions and "Common questions" answers draw on public developer discussion (Reddit r/algotrading, community GitHub issues) reviewed October 6, 2026. Community MCP repos named in code spans are public projects, not confirmed official. Truthifi data-quality figures (semantic decoders, 130+ portfolio-health checks, 18,000+ institutions) from truthifi.com / Truthifi, reviewed October 6, 2026. ↩

Related connectors in Infra/Data:

• Stripe MCP

• Alpaca MCP

• Plaid MCP

Informational only — Truthifi provides data tools, not financial, investment, tax, or legal advice. Connecting your accounts gives your AI assistant read-only access to your own data; any decisions remain yours. Product details change — confirm current specifics on the provider's official site.

Truthifi is not an investment adviser and doesn't give investment, tax or legal advice.