Create or Use a Custom Autorouter

Use algorithmFn when you want to create or use a custom autorouter in your tscircuit project without running a separate autorouter server. The function receives the board's SimpleRouteJson routing problem and returns a GenericLocalAutorouter.

This example recreates the tscircuit/example-custom-autorouter project. The board is a four-wire crossover adapter. The custom router draws Manhattan routes, cycles traces across the available layers, and uses obstacles from the SimpleRouteJson input to route around the center mounting hole.

import { SimpleCustomAutorouter } from "./src/simple-custom-autorouter"

const LEFT_HEADER_X = -13
const RIGHT_HEADER_X = 13

export default () => (
  <board
    width="34mm"
    height="22mm"
    layers={4}
    minTraceWidth={0.18}
    nominalTraceWidth={0.22}
    minViaPadDiameter={0.55}
    minViaHoleDiameter={0.3}
    pcbStyle={{
      viaPadDiameter: 0.55,
      viaHoleDiameter: 0.3,
    }}
    autorouter={{
      algorithmFn: async (simpleRouteJson) =>
        new SimpleCustomAutorouter(simpleRouteJson),
    }}
  >
    <pinheader
      name="J_LEFT"
      pinCount={4}
      pitch="2.54mm"
      pcbX={LEFT_HEADER_X}
      pcbY={0}
      pcbOrientation="vertical"
      schX={-5}
      schY={0}
      schFacingDirection="right"
    />
    <pinheader
      name="J_RIGHT"
      pinCount={4}
      pitch="2.54mm"
      pcbX={RIGHT_HEADER_X}
      pcbY={0}
      pcbOrientation="vertical"
      schX={5}
      schY={0}
      schFacingDirection="left"
    />

    <hole name="CENTER_MOUNT" diameter="3.2mm" pcbX={0} pcbY={0} />

    <silkscreentext
      text="CUSTOM ROUTER"
      pcbX={0}
      pcbY={9}
      fontSize="1mm"
      anchorAlignment="center"
    />

    <trace from=".J_LEFT > .pin1" to=".J_RIGHT > .pin4" />
    <trace from=".J_LEFT > .pin2" to=".J_RIGHT > .pin3" />
    <trace from=".J_LEFT > .pin3" to=".J_RIGHT > .pin2" />
    <trace from=".J_LEFT > .pin4" to=".J_RIGHT > .pin1" />
  </board>
)

Use an Autorouter in a Board

Pass an object with algorithmFn to the autorouter prop. The function can construct your own router, call a library, or wrap an existing routing implementation:

<board
  autorouter={{
    algorithmFn: async (simpleRouteJson) =>
      new SimpleCustomAutorouter(simpleRouteJson),
  }}
>
  {/* components and traces */}
</board>

algorithmFn receives a SimpleRouteJson object. Return an object that implements GenericLocalAutorouter, usually with these methods:

start() to begin asynchronous routing and emit a complete event
stop() to cancel routing
on("progress" | "complete" | "error", callback) to report router state
solveSync() to return SimplifiedPcbTrace[] synchronously when supported

Create a Router

The router output is a list of simplified PCB traces. Each trace should use the source trace ID when one is present, then return a route made of wire and optional via points.

The example's SimpleCustomAutorouter is intentionally small, but it shows the full shape: event handlers, sync solving, trace IDs, route widths, layer selection, obstacle checks, and progress/error reporting.

Run the Example Locally

git clone https://github.com/tscircuit/example-custom-autorouter
cd example-custom-autorouter
bun install
bun run typecheck
bun run build

Use bun run dev to open the interactive tscircuit viewer.

For a custom autorouter that runs as an HTTP service instead of inside the tscircuit process, see the Autorouting API.

Use an Autorouter in a Board​

Create a Router​

Run the Example Locally​

Use an Autorouter in a Board

Create a Router

Run the Example Locally