Rystic — Realistic API simulators for training and testing

Rystic

1 min read Original article ↗

Slack, GitHub, Kalshi, PayPal, Lob, Okta, Linear, Stripe, Resendon localhost.

Test against a simulator, not the live API.

A support agent that answers from real context

A question arrives by email or Slack. The agent reads Zendesk, the docs, Stripe, Linear and GitHub, then writes its reply from what it found.

Context

Billing and code

Email

Slack

Zendesk

Stripe

Linear

GitHub

Our simulators are…

local

Runs on your laptop or in CI, with no rate limits.

stateful

Every call sees the ones before it.

settable

Seed any state you need before the first call.

Current catalog

  • Slack

  • GitHub Pulls

  • Kalshi

  • PayPal

  • Lob

  • Okta

  • Linear

  • Stripe

  • Resend

  • Anthropic

  • Clerk

  • Dropbox

  • Gmail

  • Google Drive

  • Jira

  • Notion

  • PostHog

  • QuickBooks

  • S3

  • Shopify

  • Word

  • OpenAIsoon

  • ElevenLabssoon
  • NetSuitesoon

  • Squaresoon

  • Sentrysoon

meet the team

  • Evan Whitehouse

    Evan Whitehouse

    Co-founder

    Evan came up with Rystic while building agents on Roblox’s service mesh team, previously built virtual K8s environments at LinkedIn. Former professional Magic: the Gathering player.

  • Zachary Kiihne

    Zachary Kiihne

    Co-founder

    Zachary is a former professional magic player and spent 4 years at Google working on integrating Gemini into Gmail and Google Docs.

rystic

Test against a simulator, not the live API.