ce7cb702218693d08ea6d83464d2457c9250027c

services/codex-bridge/rpc.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os/exec"
+	"syscall"
+)
+
+type object = map[string]any
+
+type rpcError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+type event struct {
+	ID     json.RawMessage `json:"id"`
+	Method string          `json:"method"`
+	Params json.RawMessage `json:"params"`
+	Result json.RawMessage `json:"result"`
+	Error  *rpcError       `json:"error"`
+}
+
+type client struct {
+	cmd    *exec.Cmd
+	input  *json.Encoder
+	output *json.Decoder
+	id     int
+	queued []event
+}
+
+func (b *bridge) start(ctx context.Context) (*client, error) {
+	args := []string{"app-server"}
+	if b.mcpURL != "" {
+		url, err := json.Marshal(b.mcpURL)
+		if err != nil {
+			return nil, err
+		}
+		args = append(args, "-c", "mcp_servers.gateway.url="+string(url), "-c", "mcp_servers.gateway.required=true")
+	}
+	cmd := exec.CommandContext(ctx, b.binary, args...)
+	cmd.Dir = b.dir
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	cmd.Cancel = func() error { return syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL) }
+	in, err := cmd.StdinPipe()
+	if err != nil {
+		return nil, err
+	}
+	out, err := cmd.StdoutPipe()
+	if err != nil {
+		_ = in.Close()
+		return nil, err
+	}
+	if err := cmd.Start(); err != nil {
+		_ = in.Close()
+		_ = out.Close()
+		return nil, err
+	}
+	c := &client{cmd: cmd, input: json.NewEncoder(in), output: json.NewDecoder(out)}
+	if _, err := c.call("initialize", object{"clientInfo": object{"name": "codex_bridge", "version": "0.1.0"}, "capabilities": object{"experimentalApi": true}}); err != nil {
+		c.close()
+		return nil, err
+	}
+	if err := c.input.Encode(object{"method": "initialized", "params": object{}}); err != nil {
+		c.close()
+		return nil, err
+	}
+	return c, nil
+}
+
+func (c *client) close() {
+	_ = syscall.Kill(-c.cmd.Process.Pid, syscall.SIGKILL)
+	_ = c.cmd.Wait()
+}
+
+func (c *client) read() (event, error) {
+	var e event
+	if err := c.output.Decode(&e); err != nil {
+		if errors.Is(err, io.EOF) {
+			return e, errors.New("codex app-server closed its output")
+		}
+		return e, err
+	}
+	if len(e.ID) > 0 && e.Method != "" {
+		return e, fmt.Errorf("unsupported Codex client request: %s", e.Method)
+	}
+	return e, nil
+}
+
+func (c *client) call(method string, params object) (json.RawMessage, error) {
+	c.id++
+	id := fmt.Sprint(c.id)
+	if err := c.input.Encode(object{"id": c.id, "method": method, "params": params}); err != nil {
+		return nil, err
+	}
+	for {
+		e, err := c.read()
+		if err != nil {
+			return nil, err
+		}
+		if string(e.ID) != id {
+			c.queued = append(c.queued, e)
+			continue
+		}
+		if e.Error != nil {
+			return nil, fmt.Errorf("%s: %s", method, e.Error.Message)
+		}
+		return e.Result, nil
+	}
+}
+
+func (c *client) next() (event, error) {
+	if len(c.queued) == 0 {
+		return c.read()
+	}
+	e := c.queued[0]
+	c.queued = c.queued[1:]
+	return e, nil
+}