feat: add conversation schemas (#155)

apps/freya-backend/src/conversations/http.ts

@@ -1,12 +1,22 @@
 import type { Context, Hono } from "hono"
 
-import { ConversationEntryVisibility } from "@freya/core"
+import {
+	AssistantMessagePayload,
+	AttachmentPayload,
+	ConversationEntryKind,
+	ConversationEntryVisibility,
+	ContextSummaryPayload,
+	GenericObjectPayload,
+	UserMessagePayload,
+	type Conversation,
+	type ConversationEntry,
+} from "@freya/core"
 import { type } from "arktype"
 import { createMiddleware } from "hono/factory"
 
 import type { AuthSessionMiddleware } from "../auth/session-middleware.ts"
 import type { Database } from "../db/index.ts"
-import type { ConversationRow } from "./storage.ts"
+import type { ConversationEntryRow, ConversationRow } from "./storage.ts"
 
 import { ConversationNotFoundError } from "./errors.ts"
 import { conversations } from "./storage.ts"
@@ -18,19 +28,20 @@ type Env = {
 	}
 }
 
-/** Serialized conversation summary returned by the list endpoint. */
-interface ConversationSummaryResponse {
-	id: string
-	createdAt: string
-	updatedAt: string
-}
-
 /** Dependencies required to register conversation HTTP handlers. */
 interface ConversationsHttpHandlersDeps {
 	db: Database
 	authSessionMiddleware: AuthSessionMiddleware
 }
 
+interface ListConversationsResponse {
+	conversations: Conversation[]
+}
+
+interface ListConversationEntriesResponse {
+	entries: ConversationEntry[]
+}
+
 const ConversationIdParam = type("string.uuid")
 
 export function registerConversationsHttpHandlers(
@@ -49,12 +60,13 @@ export function registerConversationsHttpHandlers(
 async function handleListConversations(c: Context<Env>) {
 	const user = c.get("user")!
 	const db = c.get("db")
-
-	return c.json({
+	const response: ListConversationsResponse = {
 		conversations: (await conversations(db, user.id).listConversations()).map(
 			serializeConversation,
 		),
-	})
+	}
+
+	return c.json(response)
 }
 
 async function handleListEntries(c: Context<Env>) {
@@ -73,20 +85,11 @@ async function handleListEntries(c: Context<Env>) {
 		const entries = await conversations(db, user.id).listEntries(parsedConversationId, {
 			visibility: ConversationEntryVisibility.UserVisible,
 		})
+		const response: ListConversationEntriesResponse = {
+			entries: entries.map(serializeConversationEntry),
+		}
 
-		return c.json({
-			entries: entries.map((row) => ({
-				id: row.id,
-				conversationId: row.conversationId,
-				sequence: row.sequence,
-				kind: row.kind,
-				visibility: row.visibility,
-				fileId: row.fileId,
-				payload: row.payload,
-				metadata: row.metadata,
-				createdAt: row.createdAt.toISOString(),
-			})),
-		})
+		return c.json(response)
 	} catch (err) {
 		if (err instanceof ConversationNotFoundError) {
 			return c.json({ error: "Conversation not found" }, 404)
@@ -95,10 +98,89 @@ async function handleListEntries(c: Context<Env>) {
 	}
 }
 
-function serializeConversation(row: ConversationRow): ConversationSummaryResponse {
+function serializeConversation(row: ConversationRow): Conversation {
 	return {
 		id: row.id,
 		createdAt: row.createdAt.toISOString(),
 		updatedAt: row.updatedAt.toISOString(),
 	}
 }
+
+function serializeConversationEntry(row: ConversationEntryRow): ConversationEntry {
+	const base = {
+		id: row.id,
+		conversationId: row.conversationId,
+		sequence: row.sequence,
+		visibility: row.visibility,
+		metadata: row.metadata,
+		createdAt: row.createdAt.toISOString(),
+	}
+
+	switch (row.kind) {
+		case ConversationEntryKind.UserMessage:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: UserMessagePayload.assert(row.payload),
+			}
+		case ConversationEntryKind.AssistantMessage:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: AssistantMessagePayload.assert(row.payload),
+			}
+		case ConversationEntryKind.Attachment:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: requireFileId(row),
+				payload: AttachmentPayload.assert(row.payload),
+			}
+		case ConversationEntryKind.ToolCall:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: GenericObjectPayload.assert(row.payload),
+			}
+		case ConversationEntryKind.ToolResult:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: GenericObjectPayload.assert(row.payload),
+			}
+		case ConversationEntryKind.ContextSummary:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: ContextSummaryPayload.assert(row.payload),
+			}
+		case ConversationEntryKind.SystemNote:
+			return {
+				...base,
+				kind: row.kind,
+				fileId: nullFileId(row),
+				payload: GenericObjectPayload.assert(row.payload),
+			}
+	}
+}
+
+function requireFileId(row: ConversationEntryRow): string {
+	if (!row.fileId) {
+		throw new Error(`Conversation attachment entry "${row.id}" is missing a file id`)
+	}
+
+	return row.fileId
+}
+
+function nullFileId(row: ConversationEntryRow): null {
+	if (row.fileId !== null) {
+		throw new Error(`Conversation entry "${row.id}" unexpectedly references a file`)
+	}
+
+	return null
+}

packages/freya-core/src/conversation.test.ts

@@ -4,7 +4,11 @@ import {
 	AttachmentType,
 	AttachmentPayload,
 	ContextSummaryPayload,
+	Conversation,
+	ConversationEntry,
+	ConversationEntryKind,
 	ConversationEntryMetadata,
+	ConversationEntryVisibility,
 	GenericObjectPayload,
 	UserMessagePayload,
 } from "./conversation"
@@ -143,4 +147,99 @@ describe("conversation entry schemas", () => {
 			}),
 		).toThrow()
 	})
+
+	test("parses conversation summaries", () => {
+		const conversation = Conversation.assert({
+			id: "11111111-1111-4111-8111-111111111111",
+			createdAt: "2026-06-17T09:30:00.000Z",
+			updatedAt: "2026-06-17T09:35:00.000Z",
+		})
+
+		expect(conversation.id).toBe("11111111-1111-4111-8111-111111111111")
+	})
+
+	test("parses kind-specific conversation entries", () => {
+		const userMessageEntry = ConversationEntry.assert({
+			id: "22222222-2222-4222-8222-222222222222",
+			conversationId: "11111111-1111-4111-8111-111111111111",
+			sequence: 1,
+			kind: ConversationEntryKind.UserMessage,
+			visibility: ConversationEntryVisibility.UserVisible,
+			fileId: null,
+			payload: {
+				role: "user",
+				parts: [{ type: "text", text: "hello" }],
+			},
+			metadata: {},
+			createdAt: "2026-06-17T09:30:00.000Z",
+		})
+		const attachmentEntry = ConversationEntry.assert({
+			id: "33333333-3333-4333-8333-333333333333",
+			conversationId: "11111111-1111-4111-8111-111111111111",
+			sequence: 2,
+			kind: ConversationEntryKind.Attachment,
+			visibility: ConversationEntryVisibility.UserVisible,
+			fileId: "44444444-4444-4444-8444-444444444444",
+			payload: {
+				role: "user",
+				name: "photo.png",
+				mimeType: "image/png",
+				attachmentType: AttachmentType.Image,
+			},
+			metadata: {},
+			createdAt: "2026-06-17T09:31:00.000Z",
+		})
+
+		expect(userMessageEntry.kind).toBe(ConversationEntryKind.UserMessage)
+		expect(attachmentEntry.kind).toBe(ConversationEntryKind.Attachment)
+	})
+
+	test("rejects conversation entries whose payload does not match the kind", () => {
+		expect(() =>
+			ConversationEntry.assert({
+				id: "22222222-2222-4222-8222-222222222222",
+				conversationId: "11111111-1111-4111-8111-111111111111",
+				sequence: 1,
+				kind: ConversationEntryKind.UserMessage,
+				visibility: ConversationEntryVisibility.UserVisible,
+				fileId: null,
+				payload: {
+					role: "assistant",
+					parts: [{ type: "text", text: "hello" }],
+				},
+				metadata: {},
+				createdAt: "2026-06-17T09:30:00.000Z",
+			}),
+		).toThrow()
+	})
+
+	test("rejects serialized conversations with extra fields", () => {
+		expect(() =>
+			Conversation.assert({
+				id: "11111111-1111-4111-8111-111111111111",
+				createdAt: "2026-06-17T09:30:00.000Z",
+				updatedAt: "2026-06-17T09:35:00.000Z",
+				title: "not yet part of the schema",
+			}),
+		).toThrow()
+	})
+
+	test("rejects file ids on non-attachment entries", () => {
+		expect(() =>
+			ConversationEntry.assert({
+				id: "22222222-2222-4222-8222-222222222222",
+				conversationId: "11111111-1111-4111-8111-111111111111",
+				sequence: 1,
+				kind: ConversationEntryKind.UserMessage,
+				visibility: ConversationEntryVisibility.UserVisible,
+				fileId: "44444444-4444-4444-8444-444444444444",
+				payload: {
+					role: "user",
+					parts: [{ type: "text", text: "hello" }],
+				},
+				metadata: {},
+				createdAt: "2026-06-17T09:30:00.000Z",
+			}),
+		).toThrow()
+	})
 })

packages/freya-core/src/conversation.ts

@@ -159,3 +159,115 @@ export type ConversationEntryPayload =
 	| AttachmentPayload
 	| ContextSummaryPayload
 	| GenericObjectPayload
+
+export const Conversation = type({
+	"+": "reject",
+	id: "string.uuid",
+	createdAt: "string.date.iso",
+	updatedAt: "string.date.iso",
+})
+
+export type Conversation = typeof Conversation.infer
+
+export const UserMessageConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'user_message'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: UserMessagePayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const AssistantMessageConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'assistant_message'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: AssistantMessagePayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const AttachmentConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'attachment'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "string.uuid",
+	payload: AttachmentPayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const ToolCallConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'tool_call'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: GenericObjectPayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const ToolResultConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'tool_result'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: GenericObjectPayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const ContextSummaryConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'context_summary'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: ContextSummaryPayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const SystemNoteConversationEntry = type({
+	"+": "reject",
+	id: "string.uuid",
+	conversationId: "string.uuid",
+	sequence: "number.integer >= 1",
+	kind: "'system_note'",
+	visibility: type.enumerated(...Object.values(ConversationEntryVisibility)),
+	fileId: "null",
+	payload: GenericObjectPayload,
+	metadata: ConversationEntryMetadata,
+	createdAt: "string.date.iso",
+})
+
+export const ConversationEntry = type.or(
+	UserMessageConversationEntry,
+	AssistantMessageConversationEntry,
+	AttachmentConversationEntry,
+	ToolCallConversationEntry,
+	ToolResultConversationEntry,
+	ContextSummaryConversationEntry,
+	SystemNoteConversationEntry,
+)
+
+export type ConversationEntry = typeof ConversationEntry.infer

packages/freya-core/src/index.ts

@@ -10,10 +10,15 @@ export { UnknownActionError } from "./action"
 export type { ConversationEntryPayload } from "./conversation"
 export {
 	AssistantMessagePayload,
+	AssistantMessageConversationEntry,
 	AttachmentPayload,
+	AttachmentConversationEntry,
 	AttachmentType,
 	ContextSummary,
+	ContextSummaryConversationEntry,
 	ContextSummaryPayload,
+	Conversation,
+	ConversationEntry,
 	ConversationEntryKind,
 	ConversationEntryMetadata,
 	ConversationEntryVisibility,
@@ -21,8 +26,12 @@ export {
 	JsonMessagePart,
 	MessagePart,
 	ModelRunMetadata,
+	SystemNoteConversationEntry,
 	TextMessagePart,
+	ToolCallConversationEntry,
+	ToolResultConversationEntry,
 	UserMessagePayload,
+	UserMessageConversationEntry,
 } from "./conversation"
 
 // Feed