What is Chart Library?

Chart Library is a chart-pattern intelligence engine for humans and AI agents. Anchor any (symbol, date, timeframe) and it returns the cohort of historical analogs — from 25M+ indexed patterns across 19,000+ symbols and 10 years — what those analogs did next, and a calibrated forward-return distribution, over web, REST API, and MCP.

Does Chart Library predict stock prices?

No. Chart Library never forecasts. It returns historical distributions — what actually happened after setups like yours (median, p10/p90 band, up rate) — plus the receipts to audit them. Direction and decisions stay with you or your agent.

How calibrated are Chart Library's bands?

The nominal 80% forward-return band held 80.8% across 300,000+ live, audited cases under symbol-disjoint evaluation. The coverage record is public and recomputed continuously at chartlibrary.io/calibration.

Chart Library

Open the app Get a key

Pricing · the core loop is free

The core research loop is free — for humans and agents.

No key, no signup. The web app is free, the hosted MCP is free, and the canonical loop — search, pull_comps, introspect, track_record — is open to every human and every agent. Keys exist only to buy volume, SLAs, and premium surfaces on top of that loop. They never gate the loop itself.

What free includes · the worked row

Everything you need to run the loop, at zero cost.

This is not a trial or a teaser tier — it is the product. Anchor a chart, pull its comp set, slice it, and audit the record. No account stands between an agent and any of it.

searchAnchor any (symbol, date, timeframe); get the comp set.free

pull_compsThe 500 closest historical analogs + outcome distribution.free

introspectSlice the comp set by macro / technical / event attributes.free

track_recordThe live coverage record — the receipt you can audit.free

Hosted MCP https://chartlibrary.io/mcp·Keyless rate: 2 req/sec, burst 40·View /llms.txt →

Paid keys · agent & API infrastructure

Keys buy volume, SLAs, and premium surfaces — never the loop.

When an agent moves real traffic, a key buys a sustained lane past the keyless burst, an uptime SLA, usage metering, and operational surfaces like portfolio tracking. Same canonical tools on every tier — only the volume, rate, and surfaces change. Cancel anytime.

Keyless

The core loop, open to everyone

2 req/sec · burst 40

The full canonical loop, no key
search · pull_comps · introspect · track_record
Hosted MCP — no account, no human
Every calibration receipt, live

Start keyless

Builder

$29/mo

A keyed lane past the burst ceiling

50K calls/mo

Everything keyless, at sustained volume
60 req/min steady rate
Usage dashboard + per-key metering
Email support

Get a key

Most agents

Scale

$99/mo

Production agents under real load

500K calls/mo

Everything in Builder
300 req/min steady rate
Uptime SLA + priority queue
Priority support

Get a key

Agent

$299/mo

Fleets and premium surfaces

2M calls/mo

Everything in Scale
1,000 req/min + burst headroom
Portfolio tracking + nightly briefings
Custom partitions / adapters at GA

Get a key

Enterprise

Let's talk

Dedicated infrastructure + terms

Unmetered

Everything in Agent
Dedicated index replica
Custom SLAs + data licensing
Direct line to the team

Contact the team

Full API docs →·MCP source on GitHub →·Stripe-secure · no long-term commitment

Premium surfaces · what a key adds on top

Operational layers around the free loop.

These sit on top of the read loop — they are the reasons a desk or a production agent reaches for a key, not a paywall on the core research.

Portfolio trackinglive

Add holdings → nightly comp-set analysis → daily briefings.

Volume SLAslive

Sustained rate beyond the keyless burst, with an uptime SLA.

Usage meteringlive

Per-key dashboards, call accounting, and team seats.

Custom partitions / adaptersat GA

Calibrate over your own buckets; bring your own objective.

The web app · for individual traders

The search interface at `/app` is free, forever.

Type a ticker, anchor a chart, read the cohort and its coverage record — no account required. An optional Pro plan adds convenience layers for individual traders: AI cohort summaries, the scenario analyzer, alerts, daily setups, and portfolio briefings. The core read is never behind it.

Web app

$0/ forever

Comp-set search, outcome distribution, top matches, the coverage record, and share cards. No signup to read.

·Anchor any ticker + date
·Full cohort + 5-day distribution
·Live coverage receipt inline
·Shareable comp-set cards

Open the app →

Pro · optional

$15.83/ month

billed $190/year

Convenience layers on top of the free read — for individual traders who want the analysis written up, simulated, and delivered.

·AI cohort summaries
·Scenario analyzer
·Feature importance + regime analytics
·Risk profile + pattern memory
·Alerts + daily setups
·Portfolio briefings

Cancel anytime during trial

Cancel anytime·Stripe-secure payments·No long-term commitment·25M+ patterns · 10 years

The core research loop is free — for humans and agents.

Everything you need to run the loop, at zero cost.

Keys buy volume, SLAs, and premium surfaces — never the loop.

Operational layers around the free loop.

The search interface at /app is free, forever.

The search interface at `/app` is free, forever.