API Reference

A short list of every public export, with links to the pages that explain them.

`tacho`

export	from
`tacho()`	`tacho`	Procedure builder. Call it as `rpc({ ... })` to make a router.
`router(def)`	`tacho`	Identity helper. Same as `rpc({ ... })`.
`RpcError`	`tacho`	Throw from a procedure or middleware. See errors.
`JSON_RPC_ERROR`	`tacho`	`-32700` parse, `-32600` invalid request, `-32601` method not found, `-32602` invalid params, `-32603` internal.
`APP_ERROR_RANGE`	`tacho`	`{ min: -32099, max: -32000 }` for your own codes.
`toOpenRpc(router, info)`	`tacho`	Walk a router into an OpenRPC document.

Transports

export	from
`handle(router, opts?)`	`tacho/transport/fetch`	`(Request) => Promise<Response>`. HTTP.
`createClient(opts)`	`tacho/client/http`	Typed proxy over POST.
`handle(router, opts?)`	`tacho/transport/ws`	crossws hooks. WebSocket.
`createClient(opts)`	`tacho/client/ws`	One socket. `.ready` and `.close()`.

A File or Blob in params or the result is Files. An async function* is SSE.

Low-level

For a custom transport.

function resolveProcedure(router: AnyRouter, method: string): ProcedureDef<any, any, any> | undefinedresolveProcedure(const router: {
    ping: ProcedureDef<{}, undefined, "pong">;
}router, "ping");
await function runOne(router: AnyRouter, raw: unknown, ctx: Context, opts?: {
    stream?: false;
}): Promise<JsonRpcResponse | undefined> (+1 overload)runOne(const router: {
    ping: ProcedureDef<{}, undefined, "pong">;
}router, { jsonrpc: stringjsonrpc: "2.0", method: stringmethod: "ping", id: numberid: 1 }, const ctx: {
    req: Request;
}ctx);
await function runBatch(router: AnyRouter, items: unknown[], ctx: Context): Promise<JsonRpcErrorResponse | JsonRpcResponse[] | undefined>runBatch(
  const router: {
    ping: ProcedureDef<{}, undefined, "pong">;
}router,
  [{ jsonrpc: stringjsonrpc: "2.0", method: stringmethod: "ping", id: numberid: 1 }],
  const ctx: {
    req: Request;
}ctx,
);
function rpcResult(body: {
    result?: unknown;
    error?: {
        message: string;
        code?: number;
        data?: unknown;
    };
}): unknownrpcResult({ result?: unknownresult: "pong" });
function rpcResult(body: {
    result?: unknown;
    error?: {
        message: string;
        code?: number;
        data?: unknown;
    };
}): unknownrpcResult({ error?: {
    message: string;
    code?: number;
    data?: unknown;
} | undefinederror: { message: stringmessage: "nope", code?: number | undefinedcode: -32603 } });

const const client: RPCClient<{
    ping: ProcedureDef<{}, undefined, "pong">;
}>client = createProxyClient<{
    ping: ProcedureDef<{}, undefined, "pong">;
}, {}>(send: (method: string, params: unknown, opts?: CallOptions) => Promise<unknown>, extras?: {} | undefined): RPCClient<{
    ping: ProcedureDef<{}, undefined, "pong">;
}>createProxyClient<typeof const router: {
    ping: ProcedureDef<{}, undefined, "pong">;
}router>(
  async (method: stringmethod, params: unknownparams) => {
    const const res: JsonRpcResponse | undefinedres = await function runOne(router: AnyRouter, raw: unknown, ctx: Context, opts?: {
    stream?: false;
}): Promise<JsonRpcResponse | undefined> (+1 overload)runOne(
      const router: {
    ping: ProcedureDef<{}, undefined, "pong">;
}router,
      { jsonrpc: stringjsonrpc: "2.0", method: stringmethod, params: unknownparams, id: numberid: 1 },
      const ctx: {
    req: Request;
}ctx,
    );
    return function rpcResult(body: {
    result?: unknown;
    error?: {
        message: string;
        code?: number;
        data?: unknown;
    };
}): unknownrpcResult(const res: JsonRpcResponse | undefinedres ?? {});
  },
);
await const client: RPCClient<{
    ping: ProcedureDef<{}, undefined, "pong">;
}>client.ping: (input?: undefined, opts?: CallOptions | undefined) => Promise<"pong">ping();

export
`resolveProcedure(router, method)`	Procedure, or `undefined`.
`runOne(router, request, ctx)`	One JSON-RPC call. No `id` → `undefined` (notification).
`runBatch(router, requests, ctx)`	Many calls. All notifications → `undefined`.
`rpcResult(body)`	Result, or throws `RpcError`.
`createProxyClient(send)`	Typed proxy over your own `send`.