CrossRelay stage 2: Codex /v1/responses relay, config.toml manager, Codex page

internal/responses/types.go

@@ -0,0 +1,177 @@
+// Package responses describes the OpenAI Responses API that Codex
+// speaks and converts it to and from Chat Completions.
+package responses
+
+import (
+	"bytes"
+	"encoding/json"
+	"strings"
+)
+
+// Request is the Responses API request body. Only the fields CrossRelay
+// understands are modelled; everything else is ignored.
+type Request struct {
+	Model           string          `json:"model"`
+	Instructions    string          `json:"instructions,omitempty"`
+	Input           json.RawMessage `json:"input"`
+	Tools           []Tool          `json:"tools,omitempty"`
+	ToolChoice      json.RawMessage `json:"tool_choice,omitempty"`
+	MaxOutputTokens int             `json:"max_output_tokens,omitempty"`
+	Temperature     *float64        `json:"temperature,omitempty"`
+	TopP            *float64        `json:"top_p,omitempty"`
+	Stream          bool            `json:"stream,omitempty"`
+}
+
+// Tool is one tool definition. Type is "function" for regular tools;
+// "custom" and "local_shell" are freeform forms Codex may send.
+type Tool struct {
+	Type        string          `json:"type"`
+	Name        string          `json:"name"`
+	Description string          `json:"description,omitempty"`
+	Parameters  json.RawMessage `json:"parameters,omitempty"`
+}
+
+// Item is one entry of the input array. Only the fields belonging to
+// Type are populated.
+type Item struct {
+	Type string `json:"type"` // message | function_call | function_call_output | reasoning
+	Role string `json:"role,omitempty"`
+	// message
+	Content json.RawMessage `json:"content,omitempty"` // string or []ContentPart
+	// function_call
+	CallID    string `json:"call_id,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Arguments string `json:"arguments,omitempty"`
+	// function_call_output
+	Output json.RawMessage `json:"output,omitempty"`
+	// reasoning
+	Summary json.RawMessage `json:"summary,omitempty"`
+}
+
+// ContentPart is one part of a message item's content.
+type ContentPart struct {
+	Type string `json:"type"` // input_text | output_text | input_image
+	Text string `json:"text,omitempty"`
+	// input_image
+	ImageURL string `json:"image_url,omitempty"`
+}
+
+// Response is the Responses API response body.
+type Response struct {
+	ID                string      `json:"id"`
+	Object            string      `json:"object"`
+	CreatedAt         int64       `json:"created_at"`
+	Status            string      `json:"status"`
+	Model             string      `json:"model"`
+	Output            []OutItem   `json:"output"`
+	OutputText        string      `json:"output_text,omitempty"`
+	Usage             *Usage      `json:"usage,omitempty"`
+	IncompleteDetails *Incomplete `json:"incomplete_details,omitempty"`
+	Error             *RespError  `json:"error,omitempty"`
+}
+
+// OutItem is one output entry: an assistant message or a function call.
+type OutItem struct {
+	ID        string        `json:"id,omitempty"`
+	Type      string        `json:"type"` // message | function_call
+	Role      string        `json:"role,omitempty"`
+	Status    string        `json:"status,omitempty"`
+	Content   []ContentPart `json:"content,omitempty"`
+	CallID    string        `json:"call_id,omitempty"`
+	Name      string        `json:"name,omitempty"`
+	Arguments string        `json:"arguments,omitempty"`
+}
+
+// Usage reports token counts.
+type Usage struct {
+	InputTokens  int `json:"input_tokens"`
+	OutputTokens int `json:"output_tokens"`
+	TotalTokens  int `json:"total_tokens"`
+}
+
+// IncompleteDetails explains a non-completed response.
+type Incomplete struct {
+	Reason string `json:"reason"`
+}
+
+// RespError is the error payload of a failed response.
+type RespError struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+// ErrorResponse is the Responses API error envelope.
+type ErrorResponse struct {
+	Error Detail `json:"error"`
+}
+
+// Detail is the error payload.
+type Detail struct {
+	Type    string `json:"type"`
+	Message string `json:"message"`
+}
+
+// ParseInput decodes the input field, which is either a plain string
+// or an array of items.
+func ParseInput(raw json.RawMessage) ([]Item, error) {
+	trimmed := bytes.TrimSpace(raw)
+	if len(trimmed) == 0 || string(trimmed) == "null" {
+		return nil, nil
+	}
+	if trimmed[0] == '"' {
+		var s string
+		if err := json.Unmarshal(trimmed, &s); err != nil {
+			return nil, err
+		}
+		if s == "" {
+			return nil, nil
+		}
+		return []Item{{Type: "message", Role: "user", Content: trimmed}}, nil
+	}
+	var items []Item
+	if err := json.Unmarshal(trimmed, &items); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+// ParseContent decodes a message item's content field into parts. A
+// plain string becomes a single text part.
+func ParseContent(raw json.RawMessage) ([]ContentPart, error) {
+	trimmed := bytes.TrimSpace(raw)
+	if len(trimmed) == 0 || string(trimmed) == "null" {
+		return nil, nil
+	}
+	if trimmed[0] == '"' {
+		var s string
+		if err := json.Unmarshal(trimmed, &s); err != nil {
+			return nil, err
+		}
+		if s == "" {
+			return nil, nil
+		}
+		return []ContentPart{{Type: "input_text", Text: s}}, nil
+	}
+	var parts []ContentPart
+	if err := json.Unmarshal(trimmed, &parts); err != nil {
+		return nil, err
+	}
+	return parts, nil
+}
+
+// OutputText flattens a function_call_output output field, which is
+// either a plain string or an array of text parts.
+func OutputText(raw json.RawMessage) string {
+	parts, err := ParseContent(raw)
+	if err != nil {
+		return ""
+	}
+	var sb strings.Builder
+	for _, p := range parts {
+		switch p.Type {
+		case "output_text", "input_text", "text":
+			sb.WriteString(p.Text)
+		}
+	}
+	return sb.String()
+}