1 files changed, 55 insertions, 0 deletions
diff --git a/packages/cli/src/message.ts b/packages/cli/src/message.ts
new file mode 100644
index 0000000..0c3f538
--- /dev/null
+++ b/packages/cli/src/message.ts
@@ -0,0 +1,55 @@
+/**
+ * Pure message composition — zero I/O.
+ *
+ * Combines text and file content into a single message string,
+ * and builds a ChatRequest from a parsed command.
+ */
+
+import type { ChatRequest } from "@dispatch/transport-contract";
+
+interface ComposeInput {
+	readonly text?: string;
+	readonly file?: string;
+	readonly fileContent?: string;
+}
+
+function basename(filePath: string): string {
+	const segments = filePath.split("/");
+	return segments[segments.length - 1] ?? filePath;
+}
+
+export function composeMessage(input: ComposeInput): string {
+	const { text, fileContent } = input;
+	const file = input.file;
+
+	if (text && file) {
+		return `${text}\n\nAttached file (${basename(file)}):\n${fileContent ?? ""}`;
+	}
+	if (file) {
+		return `Attached file (${basename(file)}):\n${fileContent ?? ""}`;
+	}
+	return text ?? "";
+}
+
+interface ChatCmd {
+	readonly modelName: string;
+	readonly text?: string | undefined;
+	readonly file?: string | undefined;
+	readonly cwd?: string | undefined;
+	readonly conversationId?: string | undefined;
+	readonly showReasoning: boolean;
+}
+
+interface BuildCtx {
+	readonly cwd: string;
+	readonly message: string;
+}
+
+export function buildChatRequest(cmd: ChatCmd, ctx: BuildCtx): ChatRequest {
+	return {
+		message: ctx.message,
+		model: cmd.modelName,
+		...(cmd.conversationId !== undefined && { conversationId: cmd.conversationId }),
+		...(cmd.cwd !== undefined ? { cwd: cmd.cwd } : { cwd: ctx.cwd }),
+	};
+}