ContractSpec docs

OSS-first docs

These docs teach the open system first: contracts, generated surfaces, runtimes, governance, and incremental adoption. Studio shows up as the operating layer on top, not as the source of truth.

AI index

Windmill

Windmill is an open-source platform that turns scripts into endpoints, workflows and UIs. It seeks to remove boilerplate by generating interfaces and workflows around existing code

Platform features

  • Script-driven model.

    Write scripts in TypeScript, Python, Go, PHP, Bash, C#, SQL or Rust; Windmill infers dependencies, creates lockfiles and JSON schemas, then serves minimal UIs automatically

  • Visual flow editor.

    Compose scripts into workflows with retries, error handling, loops, branching, suspending flows and approval steps

  • Low-code UI builder.

    Build dashboards and admin panels using inline scripts and trigger flows from the UI

  • Enterprise readiness.

    Features include RBAC permissions, secret management, OAuth handling, CLI/git sync, scheduling and webhooks

  • Use cases.

    Deploy scripts as webhooks or cron jobs; create “applicative workflows” combining external APIs; build ETLs and interactive dashboards

  • Open source & self-hosting.

    Windmill emphasises an open-source codebase and self-hosting options

Comparison with ContractSpec

Feature

Windmill

ContractSpec

Entry model

Write scripts; platform auto-generates UI and workflows

Define typed specs (Capabilities, DataViews, Workflows, Policies); compiler outputs back-end, front-end and forms.

Language support

20+ languages via embedded runtimes

Uses TypeScript/JavaScript for providers; supports other back-ends through capability providers.

UI generation

Minimal UI forms from script parameters; low-code app builder

Generates full web and mobile UIs from specs; user layouts can be customised via signed overlays.

Policy & personalization

RBAC and secret management; no per-user overlay concept

Built-in policy engine enforcing ABAC/PII on every render/mutate; overlays allow safe per-user customisation.

Open source

Fully open source and self-hostable

Closed-source core (SDK is open); offers hosted and on-prem modes.

Ideal for

Teams wanting to expose scripts as APIs, workflows or dashboards without heavy infrastructure.

Teams needing a spec-driven platform that generates code and UI, enforces policies and lets non-technical users tailor the experience.

Windmill excels at converting scripts into workflows and admin panels. ContractSpec takes a spec-first approach, generating the entire stack and enforcing policies, making it suitable for long-lived applications that must evolve safely.

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Why ContractSpec

Keep educational and comparison content reachable without letting it define the primary OSS learning path.