API Reference

Build, backtest, deploy, and manage investment strategies programmatically. 21 endpoints across 5 resource types.

BASE URLhttps://api.staxlabs.org/api/v1

Getting Started

Works with Claude Code, OpenAI Codex, and the Stax CLI. Install once, then use /stax in any Claude Code session or run commands directly from the terminal.

Install via Claude Code

bash

git clone https://github.com/Stax-app/stax-skill.git ~/.claude/skills/stax

Then use /stax in any Claude Code session.

Install via Codex

bash

git clone https://github.com/Stax-app/stax-skill.git ~/.codex/skills/stax

CLI Setup

bash

cd cli && ./setup.sh && stax login

Authentication

All API requests (except GET /health) require a Bearer token. Keys are scoped to your account and can be revoked at any time.

Browser flow (recommended)

bash

stax login

Opens a browser tab for zero-paste OAuth. Key is saved to ~/.stax/config.json.

One-liner for agents / CI

bash

stax login --key sk_<id>_<secret>

Environment variable

bash

export STAX_API_KEY="sk_<id>_<secret>"

Request header format

Header

Authorization: Bearer sk_<id>_<secret>

The secret portion of your key is shown once at creation time. Store it immediately. Keys are hashed at rest — Stax cannot retrieve a lost secret.

CLI

The Stax CLI mirrors the full API surface. Run interactively or chain commands in scripts.

Interactive mode

bash

stax

Launches the REPL. Browse presets, configure strategies, run backtests — all from a guided prompt.

Direct commands

bash

stax backtest          # Run a backtest
stax screen            # Screen the stock universe
stax strategies list   # List saved strategies
stax deploy            # Deploy a strategy
stax deployments       # View active deployments
stax account           # Show tier, usage, and keys

Built-in presets

Run any preset with stax backtest --preset <name>

Preset	Momentum	Key Filters	Top N
Momentum Quality	80%	ROE ≥ 15%, rev growth ≥ 10%	10
Classic Value	0%	P/E ≤ 15, P/B ≤ 1.5	15
Dividend Compounder	30%	div yield ≥ 2%, payout ≤ 60%	20
Cash Machine	20%	FCF yield ≥ 5%, debt/eq ≤ 1.0	12
Large Cap Core	50%	market cap ≥ $50B	20

Endpoints

Core

3 endpoints

Strategies

5 endpoints

Deployments

6 endpoints

Account

4 endpoints

Community

3 endpoints

Metrics

Fundamental metrics power both the screening endpoint and strategy filters. All metrics support raw-value operators (gte, lte, gt, lt) and percentile operators (percentile_gte, percentile_lte) that rank within the current screened universe.

Metric categories

Category	Count	Examples
Profitability	12	return_on_equity, net_profit_margin, gross_profit_margin, return_on_assets
Valuation	14	price_to_earnings_ratio, price_to_book_ratio, ev_to_ebitda, price_to_sales_ratio
Growth	8	revenue_growth, earnings_growth, free_cash_flow_growth, dividend_growth
Liquidity	6	current_ratio, quick_ratio, cash_ratio, debt_to_equity
Momentum	4	price_change_1m, price_change_3m, price_change_6m, price_change_12m
Size	3	market_cap, enterprise_value, shares_outstanding

Filter operators

Operator	Description
gte	Greater than or equal to a raw value
lte	Less than or equal to a raw value
gt	Strictly greater than a raw value
lt	Strictly less than a raw value
percentile_gte	Above the Nth percentile in the universe
percentile_lte	Below the Nth percentile in the universe

Rate Limits

Backtest requests are metered per calendar day (UTC). Limits reset at 00:00 UTC. Screening, strategy CRUD, and deployment management are not metered.

10 / day

Pro

50 / day

Elite

500 / day

Unlimited

Check your current usage at any time with GET /account or stax account. The response includes rateLimits.remaining and rateLimits.resetAt.

Guardrails

Hard limits enforced on every request to keep compute times deterministic.

Limit	Value
Max symbols per backtest	1,000
Max date range	5 years
Max initial capital	$100,000,000
Equity curve max points	500
Max trades in response	10,000
Max API keys per account	5

Stax Labs API v1

Claude Code Skill