S3

Access Bulk Historical Financial Data Through S3

Retrieve large historical datasets through the FinFeedAPI Flat Files S3-compatible API.

Instead of paginating through thousands of individual API requests, research teams can browse and download compressed historical files using familiar S3 tools, SDKs, and data infrastructure.

What Is an S3 API for Financial Data?

An S3-compatible financial data API provides file-based access to historical datasets using the same interaction model and tooling commonly used with Amazon S3.

File-based historical access

Instead of requesting individual records or small time ranges through REST, applications can discover and download complete historical data files.

FinFeedAPI provides S3-compatible access through the Flat Files API, designed for workloads where large volumes of historical data need to be processed efficiently.

FinFeedAPI S3 access is focused on retrieving available historical datasets. It is not intended to function as general-purpose cloud object storage.

Typical workflows include

  • quantitative research
  • backtesting
  • machine learning
  • historical market analysis
  • data warehouse ingestion
  • batch processing
  • large-scale data pipelines

Why Use FinFeedAPI S3-Compatible Access?

REST works well for targeted queries. Large historical workloads are different. Downloading extensive datasets through many paginated API requests adds unnecessary request overhead and makes large-scale ingestion more complicated. This makes Flat Files particularly useful when the workload is defined by large historical ranges rather than individual API queries.

List → Inspect → Download

Browse available datasets, identify the files required for your research period, and download them directly.

  • Bulk historical retrieval without REST pagination
  • S3-compatible access using established tools and SDKs
  • Compressed files for efficient transfer and storage
  • Predictable dataset organization by exchange, data type, period, and date
  • Daily historical files suitable for batch processing
  • Easy integration with research and data-engineering workflows
  • Programmatic object discovery before downloading data
  • Standard S3 tooling instead of proprietary download software

Predictable Historical File Organization

Flat Files are organized into structured prefixes that make large archives easier to browse programmatically. A typical path identifies Exchange → Dataset → Period → Date. This predictable hierarchy makes it possible to identify and automate downloads for specific exchanges, datasets, periods, and dates.

Example path

s3
E-IEXG/T-OHLCV+TP-1MIN/D-20260102.csv.gz

In this structure

SegmentMeaning
E-IEXGidentifies the exchange
T-OHLCVidentifies the dataset
TP-1MINidentifies the aggregation period
D-20260102identifies the date
.csv.gzidentifies the compressed CSV format

How FinFeedAPI S3 Access Works

The core Flat Files workflow is built around three steps. Supported retrieval-oriented S3 operations include LIST, GET, and HEAD where supported. The interface is intentionally focused on accessing FinFeedAPI datasets rather than creating, uploading, deleting, or managing arbitrary customer objects.

List, inspect, then download

  1. 1List. Browse available prefixes and objects to identify the historical datasets available for your workflow.
  2. 2Inspect. Check object information and determine which files correspond to the exchange, dataset, period, and dates you need.
  3. 3Download. Retrieve the selected .csv.gz objects and process them using your preferred analytics, database, or research environment.

Use Familiar S3 Tools and SDKs

The FinFeedAPI S3-compatible interface works with common tools already used in cloud and data-engineering environments. This means existing S3-based ingestion workflows can be adapted to retrieve FinFeedAPI Flat Files without requiring a proprietary file-transfer client.

Compatible options documented by FinFeedAPI include

  • AWS CLI
  • Boto3 for Python
  • AWS SDK for JavaScript
  • AWS SDK for Java
  • AWS SDK for .NET
  • S3 Browser
  • other compatible S3 clients

Connect to the FinFeedAPI S3-Compatible API

Authentication uses your FinFeedAPI API key as the S3 Access Key ID, with S3-compatible request signing. The service supports AWS Signature Version 2 and Version 4 compatibility, and SDK configurations use the us-east-1 region. An unencrypted HTTP endpoint is also available, but HTTPS is the recommended option for production integrations.

Recommended production endpoint

https
https://s3.flatfiles.finfeedapi.com/

Examples use the bucket finfeedapi.

http
http://s3.flatfiles.finfeedapi.com/

From Dataset Prefix to Historical File

Suppose a research workflow needs historical 1-minute OHLCV data from IEXG. Instead of requesting each candle individually, the application downloads the historical file and processes the dataset locally or inside its data infrastructure. This pattern scales naturally to research workflows covering many days or larger historical ranges.

Browse the dataset, then select a date

The dataset can be browsed through:

s3
s3://finfeedapi/E-IEXG/T-OHLCV+TP-1MIN/

Individual daily files can then be selected by date:

s3
s3://finfeedapi/E-IEXG/T-OHLCV+TP-1MIN/D-20260102.csv.gz

When Should You Use S3 Flat Files?

S3-compatible Flat Files are designed for workloads where bulk historical retrieval is more efficient than individual API requests.

Quantitative Research

Load historical datasets into research environments for statistical analysis and strategy development.

Backtesting

Download defined historical periods and reuse the same files across repeated strategy simulations.

Machine Learning

Build training and validation datasets from historical market data without repeatedly querying an API.

Data Warehouses

Ingest compressed historical files into internal storage, warehouse, or analytics infrastructure.

Large Historical Backfills

Retrieve longer historical ranges without paginating through many REST responses.

Reproducible Research

Work from date-partitioned files that can be stored and reused across analytical runs.

Built for Large Historical Workloads

The difference between REST and Flat Files becomes more important as the requested historical range grows. REST is useful when an application needs a specific resource or targeted time range. Flat Files allow complete historical files to be transferred and processed in bulk.

Volume is the primary requirement

For example, a multi-month OHLCV workflow may involve discovering the required daily objects once and downloading each compressed file directly rather than issuing large numbers of smaller historical-data requests.

This makes S3-compatible delivery especially useful for data engineering, quantitative research, machine learning, and other workloads where historical volume is the primary requirement.

Best Practices for Flat Files S3 Access

Efficient Flat Files workflows start by identifying the exact dataset and date range required. The right access method depends on whether the workload is query-oriented or file-oriented.

Keep discovery and transfer aligned

  • List before downloading. Discover available objects rather than constructing large numbers of file paths blindly.
  • Use structured prefixes. Narrow listings by exchange, dataset, period, and date whenever possible.
  • Download only required dates. Avoid transferring historical files outside the research period.
  • Process compressed files efficiently. Flat Files are distributed as .csv.gz files suitable for automated pipelines.
  • Keep your API key secure. Treat S3 credentials as application secrets.
  • Use HTTPS in production. Prefer the encrypted S3-compatible endpoint.
  • Use REST for targeted queries. Small or highly specific requests may not require bulk files.
  • Use MCP for file discovery when appropriate. FinFeedAPI Flat Files also provides MCP tools for discovering buckets, prefixes, and objects.

How Flat Files Usage Is Measured

S3 workflows can involve both object operations and data transfer. The number and size of files therefore matter when planning larger historical workloads. For example, a workflow covering many daily files can include an initial object listing followed by metadata checks and downloads for each required date.

Typical operations include

  • LIST to discover available objects
  • HEAD to inspect object metadata where needed
  • GET to retrieve a file
  • Data transfer based on the files downloaded

S3 vs REST for Historical Financial Data

Choose the access method based on the size and shape of the workload. Many systems use both. REST can handle targeted queries and metadata-driven application workflows, while Flat Files provide the larger historical datasets used for research and bulk processing.

REST APIFlat Files / S3
Access modelRequest-responseFile-based retrieval
Best forTargeted queriesBulk historical data
Data selectionParameters and time rangesFiles and prefixes
Historical scaleSmall to targeted rangesLarge ranges and batch workloads
Typical processingImmediate application responseLocal, warehouse, or batch processing
Common use casesDashboards, applications, specific research queriesBacktesting, ML, warehouses, large-scale research

S3 vs Other FinFeedAPI Interfaces

FinFeedAPI provides different interfaces for different ways of consuming financial data. The interfaces are complementary rather than interchangeable. A research pipeline, for example, can use MCP to discover available Flat Files, S3 to download them, and REST for smaller targeted queries.

InterfaceBest ForTypical Use Cases
Flat Files / S3Bulk historical retrievalBacktesting, ML, research, warehouses
REST APIRequest-response accessHistorical queries, snapshots, metadata
WebSocketContinuous live streaming where supportedExchange rates, SEC filing monitoring
JSON-RPCRPC-style request-response accessRPC-based integrations
MCPAI and tool-driven workflowsAgents, copilots, data discovery
S3

Access Historical Data at Scale

Move large historical datasets into research, analytics, machine learning, and data infrastructure without relying on thousands of individual REST requests.

Use FinFeedAPI Flat Files with familiar S3-compatible tools and workflows.