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The Bridge

Declarative dataflow for API integrations

The Bridge is a hyper-lightweight execution engine that routes, reshapes, and secures traffic
Getting Started Interactive Playground

How It Works

Section titled “How It Works”

The Bridge replaces imperative orchestration code with static .bridge files. Instead of writing complex async/await logic, manual Promise.all wrappers, and custom data mappers, you simply define what data you need and where it comes from.

The Bridge engine parses your wiring diagram, builds a dependency graph, and executes it - automatically handling parallelization, fallbacks, and data reshaping.

How it looks

Section titled “How it looks”

You write the topology; the engine handles the execution.

version 1.5


# 1. Define your tools (APIs, DB queries, or custom TS functions)
tool geo from httpCall { .baseUrl = "https://api.map.com" }
tool weather from httpCall { .baseUrl = "https://api.weather.com" }


bridge Query.should_i_go_outside {
  with geo
  with weather
  with input as i
  with output as o


  # 2. Wire inputs to tools
  geo.city <- i.cityName


  # 3. Chain tools together (Engine auto-resolves dependencies)
  weather.lat <- geo.lat
  weather.lon <- geo.lon


  # 4. Map the final output
  o.why.temperature <- weather.current.tempC ?? 0.0


  # 5. Final decision (business rules)
  o.decision <- weather.current.tempC > 25
}


# should_i_go_outside({cityName: "San Francisco"}) => { decision: true, why: { temperature: 28 }}

Why a language instead of code?

Section titled “Why a language instead of code?”
  • Zero Orchestration Boilerplate: The engine inherently knows which tools can run concurrently. No manual Promise.all or batching logic required.
  • Separation of Concerns: Keep your core business logic inside isolated TypeScript tools, completely separate from your routing, mapping, and orchestration logic.
  • Safe for LLM Automation: Because The Bridge is a strictly declarative, constrained dataflow language, it is much safer for AI generation than general-purpose code. You can confidently let an LLM wire up your API mappings without the risk of it hallucinating infinite loops, memory leaks, or rogue system calls.
  • Hot-Reloadable Logic: Since .bridge files are just text parsed into an execution graph, you don’t need to recompile, rebuild, or redeploy your entire Node application to change a data mapping or swap an API provider. You can update and hot-reload your rules on the fly.
  • Portable Execution: The engine is hyper-lightweight and framework-agnostic. Run it in a Node backend, an Edge Worker (Cloudflare/Vercel), or directly in the browser.

Primary Use Cases

Section titled “Primary Use Cases”

Because The Bridge strictly controls how data flows from inputs to tools to outputs, it is the perfect engine for architectures that require strict boundaries and clean mappings.

  1. The “No-Code” BFF (Backend-for-Frontend) Spin up a GraphQL BFF without maintaining a secondary codebase of resolvers, types, and DTOs. Frontend teams can aggregate and shape backend data just by writing .bridge files.
  2. The Egress Gateway Funnel external third-party API calls through a single point. Swap providers (e.g., SendGrid ↔ AWS SES) by changing a .bridge file without ever touching the calling service’s code.
  3. The Rule Engine / Policy Evaluator Encapsulate complex conditional business logic and data enrichment into a single, highly readable file that returns a boolean. Perfect for authorization checks or fraud detection flows.
Section titled “Read Next”

Standard Library

Browse all built-in tools — HTTP client, string & array helpers, audit logging, and more.

VS Code extension

To get syntax highlighting and IntelliSense install the VS Code extension.

The Bridge - Declarative dataflow for API integrations | Product Hunt