FAQ
Frequently asked questions
Start with the decision: compare a prediction with a modeled action, test the distinction in Spark, then carry the reasoning into a licensed SDK when your product needs it.
From prediction to action
Why not stop at a prediction?
A prediction asks what is likely under observed evidence. An intervention asks what the declared causal model predicts when you set an action instead. In the Simpson Recovery example, compare observing Treatment = treated with setting do(Treatment = treated) on the same graph, then inspect why the Recovery posterior moves. Sign in and open Simpson Recovery from Examples.
Can I test prediction against action before paying?
Yes. Spark opens the workspace without a card. After signing in, choose Examples, load Simpson Recovery, and compare the observed Treatment value with the adjacent do intervention. Workspace access, saved files, sharing, and graph limits continue to follow the current plan contract. Review Spark and paid plan boundaries.
How does inspected reasoning reach a production application?
Use the public SDK guides to inspect the named prediction, intervention, counterfactual, or decision operation for your model family, then license the exact language and platform your application needs. An Online subscription does not include an SDK license, and production deployment guidance is delivered with the licensed artifact. Inspect public SDK guidance and examples.
When should I use an SDK instead of MCP?
Use a licensed SDK to embed supported Darkstar capabilities in an application or service you build and operate. MCP exposes supported capabilities to an authorized agent client and returns a structured result, job, or refusal. MCP access follows the configured deployment, authorization, plan, and runtime policies. Compare application and agent integration.
Accounts and billing
What is Darkstar Online?
Darkstar Online is a self-serve Causal AI workspace for building Bayesian-network decision models, testing evidence, interventions, counterfactuals, and sensitivity, using Studio influence diagrams for policy and VOI analysis, saving cloud documents, sharing review links, and moving into licensed SDK deployment.
Does Spark require a card?
No. Spark opens the workspace without collecting a payment method. Paid upgrades use Stripe Checkout.
What happens if I cancel a paid plan?
Cancellation keeps paid access through the current paid period. After expiration, the account can continue at Spark limits. Upgrade again to restore paid cloud, sharing, support, and graph limits.
Can I switch between paid plans?
Yes. Existing paid subscriptions change through the Stripe billing portal. Upgrades are intended to apply immediately with Stripe proration, while downgrades are scheduled for the end of the current paid period.
Which plans are available?
Spark is the entry tier. Pro is billed monthly, Premium is billed every six months, and Studio is billed annually. Studio has the highest self-service limits and includes influence diagrams, VOI ranking, and public read-only sharing.
Does Rocket Vector store card numbers?
No. Stripe stores payment methods, handles invoices, and runs recurring billing. Darkstar stores billing consent, subscription status, and Stripe references needed to manage access.
Can I change my payment method?
Yes. The public Plans page explains the flow, and signed-in users can open the Stripe billing portal from the internal Plans page to update payment methods and view invoices.
Workspace and files
How are graph documents saved?
Spark documents stay local through download, import, and browser recovery. Paid plans save graph documents to cloud storage with Firestore metadata, SHA-256 hashes, soft deletes, and autosave.
Which export formats are available?
Spark exports PNG images and normalized JSON documents. Paid plans can export graph images as SVG, PNG, or JPEG.
Are sampling and layouts limited by plan?
Yes. Tier limits control sampling rows, runtime operations, node counts, arc counts, parents per node, states per node, and CPT size. The app enforces those limits while you build.
Do the analysis tools include sensitivity and value of information?
Yes. The workspace can rank CPT sensitivity for Bayesian networks. Studio adds influence diagrams, expected utility policy solving, and value-of-information ranking for candidate observations.
Sharing and support
Can I share a model publicly?
Paid saved cloud documents can be published as revocable read-only shares. Studio supports public unlisted links, and Pro and Premium support invited recipient links within plan limits.
How do I contact Rocket Vector?
Use the Contact page if you are anonymous or signed out. Paid signed-in users can create an in-app support ticket from the account area. Open contact.
SDKs and commercial licensing
How are the SDKs sold?
Darkstar SDKs are sold per platform, per language, and per paid license type. The catalog is 13 languages across Windows, Linux, and macOS for 39 platform-language targets, with Developer Seat, Solo Internal Runtime, and Small Team Internal Runtime bringing the paid total to 117 products before support add-ons. Open SDK pricing.
Is SDK support included?
No. SDK technical support is purchased separately through ticket credits or support plans. Anonymous visitors start on the Contact page, while signed-in eligible customers use tickets from the account area. Open contact.
Are all SDK docs public?
Public docs cover trust-building and API shape, including influence-diagram policy solving and analysis-pattern examples. High-value customer docs such as production deployment, compatibility notes, and packaging recipes are versioned to the licensed artifact and delivered through the account surface. Open SDK docs.