Migrate from Intrinio

This guide is for developers who call the Intrinio API v2 and want to run the same app on Massive. It maps each common endpoint to the Massive endpoint that replaces it, and lists the differences that change your results. To compare the two products before you switch, see Massive vs Intrinio.

If your product depends on Intrinio data that Massive doesn't currently offer, such as mutual funds or ESG scores, you can keep Intrinio for that and use Massive for prices, options, and futures.

Before you start

• Sign up and copy your API key from the dashboard.
• Pick a plan for each market you use on the pricing page.
• Read the REST quickstart for the response shape that every endpoint shares.

Using AI?

Paste this into Claude Code, Cursor, Codex, or any coding agent that can read files and fetch a URL:

Find every place my project calls Intrinio.
Switch those calls to the Massive REST API.
Read https://massive.com/docs/migration/guides/intrinio.md for the endpoint map and the differences to handle.
Read https://massive.com/docs/llms.txt for the rest of the API.
Read the API key from the MASSIVE_API_KEY environment variable.
Keep my function signatures and data shapes the same, and list anything Massive does not cover.

To let the agent check real responses while it works, connect the Massive MCP server. Massive also publishes skills and plugins for coding agents.

The request

Both APIs take the key in an Authorization: Bearer header, and both treat the start and end dates as inclusive. Intrinio puts the dates in query parameters. Massive puts them in the path.

curl "https://api-v2.intrinio.com/securities/AAPL/prices?start_date=2025-10-01&end_date=2025-10-03&frequency=daily" \
  -H "Authorization: Bearer YOUR_API_KEY"

curl "https://api.massive.com/v2/aggs/ticker/AAPL/range/1/day/2025-10-01/2025-10-03?adjusted=false" \
  -H "Authorization: Bearer YOUR_API_KEY"

from massive import RESTClient

client = RESTClient("YOUR_API_KEY")
bars = list(client.list_aggs("AAPL", 1, "day", "2025-10-01", "2025-10-03", adjusted=False))

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/massive-com/client-go/v3/rest"
	"github.com/massive-com/client-go/v3/rest/gen"
)

func main() {
	c := rest.NewWithOptions("YOUR_API_KEY", rest.WithPagination(true))
	ctx := context.Background()

	params := &gen.GetStocksAggregatesParams{
		Adjusted: rest.Ptr(false),
		Sort:     "asc",
	}

	resp, err := c.GetStocksAggregatesWithResponse(ctx, "AAPL", 1, "day", "2025-10-01", "2025-10-03", params)
	if err != nil {
		log.Fatal(err)
	}
	if err := rest.CheckResponse(resp); err != nil {
		log.Fatal(err)
	}

	iter := rest.NewIteratorFromResponse(c, resp)
	for iter.Next() {
		fmt.Printf("%+v\n", iter.Item())
	}
	if err := iter.Err(); err != nil {
		log.Fatal(err)
	}
}

import { restClient } from '@massive.com/client-js';

const rest = restClient('YOUR_API_KEY', 'https://api.massive.com');

const response = await rest.getStocksAggregates({
  stocksTicker: "AAPL",
  multiplier: "1",
  timespan: "day",
  from: "2025-10-01",
  to: "2025-10-03",
  adjusted: "false"
});

import com.massive.client.apis.DefaultApi
import com.massive.client.apis.DefaultApi.TimespanGetStocksAggregates
import com.massive.client.infrastructure.*

fun main() {
    ApiClient.apiKey["apiKey"] = "YOUR_API_KEY"

    val bars = DefaultApi().getStocksAggregates(
        stocksTicker = "AAPL",
        multiplier = 1,
        timespan = TimespanGetStocksAggregates.day,
        from = "2025-10-01",
        to = "2025-10-03",
        adjusted = false
    )
    println(bars)
}

• Identifiers. Intrinio accepts a ticker, FIGI, ISIN, CUSIP, or Intrinio ID in the path. Massive takes tickers in the path. To find the ticker for a CUSIP, call All Tickers with cusip.
• Paging. Intrinio returns a next_page token. Massive returns a next_url to call as is. The Python client follows it for you.

The response

Intrinio returns raw prices, plus adj_* fields adjusted for splits and dividends:

{
  "stock_prices": [
    {
      "date": "2025-10-01",
      "open": 255.04,
      "high": 258.79,
      "low": 254.93,
      "close": 255.45
    }
  ],
  "next_page": null
}

Massive returns one set of prices, chosen by adjusted:

{
  "results": [
    {
      "t": 1759291200000,
      "o": 255.04,
      "h": 258.79,
      "l": 254.93,
      "c": 255.45,
      "v": 48713940,
      "vw": 256.004,
      "n": 535581
    }
  ]
}

• Weekly and monthly bars. Intrinio dates each row on the last day of the period. Massive t is the start of the period.
• Intraday times. Intrinio returns time in the timezone you request. Massive returns Unix milliseconds, so convert them yourself.

Symbols

Prices

• Set adjusted=false on Massive to match Intrinio's raw open, high, low, close, and volume.
• No Massive setting matches the adj_* fields, because they include dividends. To rebuild them, use the historical adjustment factor from Dividends.
• If you need both raw and split-adjusted prices, make two requests.

Sources: Intrinio authentication, paging, stock prices by security.

Endpoint map

This map covers the most common calls. It is not a full list. To find the Massive endpoint for another call, search these docs.

Massive currently doesn't have an equivalent for Intrinio ESG data, mutual funds, or lookups by FIGI or ISIN. New data and features ship often, so check the product roadmap for what's planned. Massive adds forex, crypto, indices, and futures.

Streaming

Intrinio real-time data comes through its realtime SDKs. Each SDK gets a token from a feed host, then joins tickers on a WebSocket. Massive takes your API key in an auth message on the WebSocket itself:

• Stocks: connect to wss://socket.massive.com/stocks and subscribe to trades and quotes.
• Options: connect to wss://socket.massive.com/options and subscribe to trades and quotes.

See the WebSocket quickstart.

Bulk history

Intrinio serves bulk downloads as links from /bulk_downloads/links. Massive flat files are on an S3-compatible endpoint, so you can sync them with standard S3 tools. Each file holds one day of stock trades, stock daily bars, or options daily bars.

SDKs

Sources

Intrinio details were checked against the Intrinio API documentation on October 29, 2026. Intrinio is a trademark of its owner. Massive is not affiliated with Intrinio.