diff --git a/src/lib/conversation-schema/content/ImageContentSchema.ts b/src/lib/conversation-schema/content/ImageContentSchema.ts
new file mode 100644
index 0000000..a08df21
--- /dev/null
+++ b/src/lib/conversation-schema/content/ImageContentSchema.ts
@@ -0,0 +1,10 @@
+import { z } from 'zod'
+
+export const ImageContentSchema = z.object({
+  type: z.literal('image'),
+  source: z.object({
+    type: z.literal('base64'),
+    data: z.string(),
+    media_type: z.enum(['image/png']),
+  }),
+}).strict()
diff --git a/src/lib/conversation-schema/content/TextContentSchema.ts b/src/lib/conversation-schema/content/TextContentSchema.ts
new file mode 100644
index 0000000..46eb68b
--- /dev/null
+++ b/src/lib/conversation-schema/content/TextContentSchema.ts
@@ -0,0 +1,6 @@
+import { z } from 'zod'
+
+export const TextContentSchema = z.object({
+  type: z.literal('text'),
+  text: z.string(),
+}).strict()
diff --git a/src/lib/conversation-schema/content/ThinkingContentSchema.ts b/src/lib/conversation-schema/content/ThinkingContentSchema.ts
new file mode 100644
index 0000000..b77bb1d
--- /dev/null
+++ b/src/lib/conversation-schema/content/ThinkingContentSchema.ts
@@ -0,0 +1,7 @@
+import { z } from 'zod'
+
+export const ThinkingContentSchema = z.object({
+  type: z.literal('thinking'),
+  thinking: z.string(),
+  signature: z.string().optional(),
+}).strict()
diff --git a/src/lib/conversation-schema/content/ToolResultContentSchema.ts b/src/lib/conversation-schema/content/ToolResultContentSchema.ts
new file mode 100644
index 0000000..0fe2a49
--- /dev/null
+++ b/src/lib/conversation-schema/content/ToolResultContentSchema.ts
@@ -0,0 +1,16 @@
+import { z } from 'zod'
+import { TextContentSchema } from './TextContentSchema'
+import { ImageContentSchema } from './ImageContentSchema'
+
+export const ToolResultContentSchema = z.object({
+  type: z.literal('tool_result'),
+  tool_use_id: z.string(),
+  content: z.union([z.string(), z.array(z.union([
+    TextContentSchema,
+    ImageContentSchema
+  ]))]),
+  is_error: z.boolean().optional(),
+}).strict()
+
+
+export type ToolResultContent = z.infer<typeof ToolResultContentSchema>
diff --git a/src/lib/conversation-schema/content/ToolUseContentSchema.ts b/src/lib/conversation-schema/content/ToolUseContentSchema.ts
new file mode 100644
index 0000000..799285c
--- /dev/null
+++ b/src/lib/conversation-schema/content/ToolUseContentSchema.ts
@@ -0,0 +1,8 @@
+import { z } from 'zod'
+
+export const ToolUseContentSchema = z.object({
+  type: z.literal('tool_use'),
+  id: z.string(),
+  name: z.string(),
+  input: z.record(z.string(), z.unknown()),
+}).strict()
diff --git a/src/lib/conversation-schema/entry/AssistantEntrySchema.ts b/src/lib/conversation-schema/entry/AssistantEntrySchema.ts
new file mode 100644
index 0000000..d4130fc
--- /dev/null
+++ b/src/lib/conversation-schema/entry/AssistantEntrySchema.ts
@@ -0,0 +1,15 @@
+import { z } from 'zod'
+import { AssistantMessageSchema } from '../message/AssistantMessageSchema'
+import { BaseEntrySchema } from './BaseEntrySchema'
+
+export const AssistantEntrySchema = BaseEntrySchema.extend({
+  // discriminator
+  type: z.literal('assistant'),
+
+  // required
+  message: AssistantMessageSchema,
+
+  // optional
+  requestId: z.string().optional(),
+  isApiErrorMessage: z.boolean().optional(),
+}).strict()
diff --git a/src/lib/conversation-schema/entry/BaseEntrySchema.ts b/src/lib/conversation-schema/entry/BaseEntrySchema.ts
new file mode 100644
index 0000000..12d1498
--- /dev/null
+++ b/src/lib/conversation-schema/entry/BaseEntrySchema.ts
@@ -0,0 +1,21 @@
+import { z } from 'zod'
+
+export const BaseEntrySchema = z.object({
+  // required
+  isSidechain: z.boolean(),
+  userType: z.enum(['external']),
+  cwd: z.string(),
+  sessionId: z.string(),
+  version: z.string(),
+  uuid: z.uuid(),
+  timestamp: z.string(),
+
+  // nullable
+  parentUuid: z.uuid().nullable(),
+
+  // optional
+  isMeta: z.boolean().optional(),
+  toolUseResult: z.unknown().optional(), // スキーマがツールごとに異なりすぎるし利用もしなそうなので unknown
+  gitBranch: z.string().optional(),
+  isCompactSummary: z.boolean().optional(),
+}).strict()
diff --git a/src/lib/conversation-schema/entry/SummaryEntrySchema.ts b/src/lib/conversation-schema/entry/SummaryEntrySchema.ts
new file mode 100644
index 0000000..7c798d1
--- /dev/null
+++ b/src/lib/conversation-schema/entry/SummaryEntrySchema.ts
@@ -0,0 +1,7 @@
+import { z } from 'zod'
+
+export const SummaryEntrySchema = z.object({
+  type: z.literal('summary'),
+  summary: z.string(),
+  leafUuid: z.string().uuid(),
+}).strict()
diff --git a/src/lib/conversation-schema/entry/SystemEntrySchema.ts b/src/lib/conversation-schema/entry/SystemEntrySchema.ts
new file mode 100644
index 0000000..a232731
--- /dev/null
+++ b/src/lib/conversation-schema/entry/SystemEntrySchema.ts
@@ -0,0 +1,12 @@
+import { z } from 'zod'
+import { BaseEntrySchema } from './BaseEntrySchema'
+
+export const SystemEntrySchema = BaseEntrySchema.extend({
+  // discriminator
+  type: z.literal('system'),
+
+  // required
+  content: z.string(),
+  toolUseID: z.string(),
+  level: z.enum(['info']),
+}).strict()
diff --git a/src/lib/conversation-schema/entry/UserEntrySchema.ts b/src/lib/conversation-schema/entry/UserEntrySchema.ts
new file mode 100644
index 0000000..56f1f13
--- /dev/null
+++ b/src/lib/conversation-schema/entry/UserEntrySchema.ts
@@ -0,0 +1,11 @@
+import { z } from 'zod'
+import { UserMessageSchema } from '../message/UserMessageSchema'
+import { BaseEntrySchema } from './BaseEntrySchema'
+
+export const UserEntrySchema = BaseEntrySchema.extend({
+  // discriminator
+  type: z.literal('user'),
+
+  // required
+  message: UserMessageSchema,
+}).strict()
diff --git a/src/lib/conversation-schema/index.ts b/src/lib/conversation-schema/index.ts
new file mode 100644
index 0000000..1f533b9
--- /dev/null
+++ b/src/lib/conversation-schema/index.ts
@@ -0,0 +1,14 @@
+import { z } from 'zod'
+import { UserEntrySchema } from './entry/UserEntrySchema'
+import { AssistantEntrySchema } from './entry/AssistantEntrySchema'
+import { SummaryEntrySchema } from './entry/SummaryEntrySchema'
+import { SystemEntrySchema } from './entry/SystemEntrySchema'
+
+export const ConversationSchema = z.union([
+  UserEntrySchema,
+  AssistantEntrySchema,
+  SummaryEntrySchema,
+  SystemEntrySchema,
+])
+
+export type Conversation = z.infer<typeof ConversationSchema>
diff --git a/src/lib/conversation-schema/message/AssistantMessageSchema.ts b/src/lib/conversation-schema/message/AssistantMessageSchema.ts
new file mode 100644
index 0000000..de16f6d
--- /dev/null
+++ b/src/lib/conversation-schema/message/AssistantMessageSchema.ts
@@ -0,0 +1,38 @@
+import { z } from 'zod'
+import { ThinkingContentSchema } from '../content/ThinkingContentSchema'
+import { TextContentSchema } from '../content/TextContentSchema'
+import { ToolUseContentSchema } from '../content/ToolUseContentSchema'
+import { ToolResultContentSchema } from '../content/ToolResultContentSchema'
+
+const AssistantMessageContentSchema = z.union([
+  ThinkingContentSchema,
+  TextContentSchema,
+  ToolUseContentSchema,
+  ToolResultContentSchema,
+])
+
+export type AssistantMessageContent = z.infer<typeof AssistantMessageContentSchema>
+
+export const AssistantMessageSchema = z.object({
+  id: z.string(),
+  type: z.literal('message'),
+  role: z.literal('assistant'),
+  model: z.string(),
+  content: z.array(AssistantMessageContentSchema),
+  stop_reason: z.string().nullable(),
+  stop_sequence: z.string().nullable(),
+  usage: z.object({
+    input_tokens: z.number(),
+    cache_creation_input_tokens: z.number().optional(),
+    cache_read_input_tokens: z.number().optional(),
+    cache_creation: z.object({
+      ephemeral_5m_input_tokens: z.number(),
+      ephemeral_1h_input_tokens: z.number(),
+    }).optional(),
+    output_tokens: z.number(),
+    service_tier: z.string().nullable().optional(),
+    server_tool_use: z.object({
+      web_search_requests: z.number(),
+    }).optional(),
+  }),
+}).strict()
diff --git a/src/lib/conversation-schema/message/UserMessageSchema.ts b/src/lib/conversation-schema/message/UserMessageSchema.ts
new file mode 100644
index 0000000..675e496
--- /dev/null
+++ b/src/lib/conversation-schema/message/UserMessageSchema.ts
@@ -0,0 +1,25 @@
+import { z } from 'zod'
+import { ToolResultContentSchema } from '../content/ToolResultContentSchema'
+import { TextContentSchema } from '../content/TextContentSchema'
+import { ImageContentSchema } from '../content/ImageContentSchema'
+
+
+const UserMessageContentSchema = z.union([
+  z.string(),
+  TextContentSchema,
+  ToolResultContentSchema,
+  ImageContentSchema
+])
+
+export type UserMessageContent = z.infer<typeof UserMessageContentSchema>
+
+export const UserMessageSchema = z.object({
+  role: z.literal('user'),
+  content: z.union([
+    z.string(),
+    z.array(z.union([
+      z.string(),
+      UserMessageContentSchema
+    ]))
+  ]),
+}).strict()
diff --git a/src/lib/conversation-schema/tool/CommonToolSchema.ts b/src/lib/conversation-schema/tool/CommonToolSchema.ts
new file mode 100644
index 0000000..132982f
--- /dev/null
+++ b/src/lib/conversation-schema/tool/CommonToolSchema.ts
@@ -0,0 +1,59 @@
+import { z } from 'zod'
+import { StructuredPatchSchema } from './StructuredPatchSchema'
+
+export const CommonToolResultSchema = z.union([
+  z.object({
+    stdout: z.string(),
+    stderr: z.string(),
+    interrupted: z.boolean(),
+    isImage: z.boolean(),
+  }).strict(),
+
+  // create
+  z.object({
+    type: z.literal('create'),
+    filePath: z.string(),
+    content: z.string(),
+    structuredPatch: z.array(StructuredPatchSchema)
+  }).strict(),
+  
+  // update
+  z.object({
+    filePath: z.string(),
+    oldString: z.string(),
+    newString: z.string(),
+    originalFile: z.string(),
+    userModified: z.boolean(),
+    replaceAll: z.boolean(),
+    structuredPatch: z.array(StructuredPatchSchema)
+  }).strict(),
+
+  // search?
+  z.object({
+    filenames: z.array(z.string()),
+    durationMs: z.number(),
+    numFiles: z.number(),
+    truncated: z.boolean(),
+  }).strict(),
+
+  // text
+  z.object({
+    type: z.literal('text'),
+    file: z.object({
+      filePath: z.string(),
+      content: z.string(),
+      numLines: z.number(),
+      startLine: z.number(),
+      totalLines: z.number(),
+    })
+  }).strict(),
+
+  // content
+  z.object({
+    mode: z.literal('content'),
+    numFiles: z.number(),
+    filenames: z.array(z.string()),
+    content: z.string(),
+    numLines: z.number(),
+  }).strict(),
+])
diff --git a/src/lib/conversation-schema/tool/StructuredPatchSchema.ts b/src/lib/conversation-schema/tool/StructuredPatchSchema.ts
new file mode 100644
index 0000000..8922a65
--- /dev/null
+++ b/src/lib/conversation-schema/tool/StructuredPatchSchema.ts
@@ -0,0 +1,9 @@
+import { z } from 'zod'
+
+export const StructuredPatchSchema = z.object({
+  oldStart: z.number(),
+  oldLines: z.number(),
+  newStart: z.number(),
+  newLines: z.number(),
+  lines: z.array(z.string()),
+}).strict()
diff --git a/src/lib/conversation-schema/tool/TodoSchema.ts b/src/lib/conversation-schema/tool/TodoSchema.ts
new file mode 100644
index 0000000..61e16b4
--- /dev/null
+++ b/src/lib/conversation-schema/tool/TodoSchema.ts
@@ -0,0 +1,13 @@
+import z from "zod";
+
+const TodoSchema = z.object({
+  content: z.string(),
+  status: z.enum(['pending', 'in_progress', 'completed']),
+  priority: z.enum(['low', 'medium', 'high']),
+  id: z.string(),
+}).strict()
+
+export const TodoToolResultSchema = z.object({
+  oldTodos: z.array(TodoSchema).optional(),
+  newTodos: z.array(TodoSchema).optional(),
+}).strict()
diff --git a/src/lib/conversation-schema/tool/index.ts b/src/lib/conversation-schema/tool/index.ts
new file mode 100644
index 0000000..48d2fa5
--- /dev/null
+++ b/src/lib/conversation-schema/tool/index.ts
@@ -0,0 +1,9 @@
+import { z } from "zod";
+import { TodoToolResultSchema } from "./TodoSchema";
+import { CommonToolResultSchema } from "./CommonToolSchema";
+
+export const ToolUseResultSchema = z.union([
+  z.string(),
+  TodoToolResultSchema,
+  CommonToolResultSchema,
+]);
diff --git a/src/server/hono/route.ts b/src/server/hono/route.ts
index a1fbb10..70b590b 100644
--- a/src/server/hono/route.ts
+++ b/src/server/hono/route.ts
@@ -1,20 +1,32 @@
-import { zValidator } from "@hono/zod-validator";
-import { z } from "zod";
 import type { HonoAppType } from "./app";
-
-const helloBodySchema = z.object({
-  name: z.string(),
-});
+import { getProjects } from "../service/project/getProjects";
+import { getProject } from "../service/project/getProject";
+import { getSessions } from "../service/session/getSessions";
+import { getSession } from "../service/session/getSession";
 
 export const routes = (app: HonoAppType) => {
-  return (
-    app
-      // routes
-      .get("/hello", zValidator("json", helloBodySchema), (c) => {
-        const { name } = c.req.valid("json");
-        return c.json({ message: `Hello ${name}` });
-      })
-  );
+  return app
+    .get("/projects", async (c) => {
+      const { projects } = await getProjects();
+      return c.json({ projects });
+    })
+
+    .get("/projects/:projectId", async (c) => {
+      const { projectId } = c.req.param();
+
+      const [{ project }, { sessions }] = await Promise.all([
+        getProject(projectId),
+        getSessions(projectId),
+      ] as const);
+
+      return c.json({ project, sessions });
+    })
+
+    .get("/projects/:projectId/sessions/:sessionId", async (c) => {
+      const { projectId, sessionId } = c.req.param();
+      const { session } = await getSession(projectId, sessionId);
+      return c.json({ session });
+    });
 };
 
 export type RouteType = ReturnType<typeof routes>;
diff --git a/src/server/service/parseCommandXml.ts b/src/server/service/parseCommandXml.ts
new file mode 100644
index 0000000..d00388a
--- /dev/null
+++ b/src/server/service/parseCommandXml.ts
@@ -0,0 +1,82 @@
+import { z } from "zod";
+
+const regExp = /<(?<tag>[^>]+)>(?<content>\s*[^<]*?\s*)<\/\k<tag>>/g;
+
+const matchSchema = z.object({
+  tag: z.string(),
+  content: z.string(),
+});
+
+export const parseCommandXml = (
+  content: string
+):
+  | {
+      kind: "command";
+      commandName: string;
+      commandArgs: string;
+      commandMessage?: string;
+    }
+  | {
+      kind: "local-command-1";
+      commandName: string;
+      commandMessage: string;
+    }
+  | {
+      kind: "local-command-2";
+      stdout: string;
+    }
+  | {
+      kind: "text";
+      content: string;
+    } => {
+  const matches = Array.from(content.matchAll(regExp))
+    .map((match) => matchSchema.safeParse(match.groups))
+    .filter((result) => result.success)
+    .map((result) => result.data);
+
+  if (matches.length === 0) {
+    return {
+      kind: "text",
+      content,
+    };
+  }
+
+  const commandName = matches.find(
+    (match) => match.tag === "command-name"
+  )?.content;
+  const commandArgs = matches.find(
+    (match) => match.tag === "command-args"
+  )?.content;
+  const commandMessage = matches.find(
+    (match) => match.tag === "command-message"
+  )?.content;
+  const localCommandStdout = matches.find(
+    (match) => match.tag === "local-command-stdout"
+  )?.content;
+
+  switch (true) {
+    case commandName !== undefined && commandArgs !== undefined:
+      return {
+        kind: "command",
+        commandName,
+        commandArgs,
+        commandMessage: commandMessage,
+      };
+    case commandName !== undefined && commandMessage !== undefined:
+      return {
+        kind: "local-command-1",
+        commandName,
+        commandMessage,
+      };
+    case localCommandStdout !== undefined:
+      return {
+        kind: "local-command-2",
+        stdout: localCommandStdout,
+      };
+    default:
+      return {
+        kind: "text",
+        content,
+      };
+  }
+};
diff --git a/src/server/service/parseJsonl.ts b/src/server/service/parseJsonl.ts
new file mode 100644
index 0000000..a22a312
--- /dev/null
+++ b/src/server/service/parseJsonl.ts
@@ -0,0 +1,18 @@
+import { ConversationSchema } from "../../lib/conversation-schema";
+
+export const parseJsonl = (content: string) => {
+  const lines = content
+    .trim()
+    .split("\n")
+    .filter((line) => line.trim() !== "");
+
+  return lines.flatMap((line) => {
+    const parsed = ConversationSchema.safeParse(JSON.parse(line));
+    if (!parsed.success) {
+      console.warn("Failed to parse jsonl, skipping", parsed.error);
+      return [];
+    }
+
+    return parsed.data;
+  });
+};
diff --git a/src/server/service/paths.ts b/src/server/service/paths.ts
new file mode 100644
index 0000000..e87e728
--- /dev/null
+++ b/src/server/service/paths.ts
@@ -0,0 +1,4 @@
+import { homedir } from "node:os";
+import { resolve } from "node:path";
+
+export const claudeProjectPath = resolve(homedir(), ".claude", "projects");
diff --git a/src/server/service/project/getProject.ts b/src/server/service/project/getProject.ts
new file mode 100644
index 0000000..09b9e24
--- /dev/null
+++ b/src/server/service/project/getProject.ts
@@ -0,0 +1,24 @@
+import { existsSync } from "node:fs";
+
+import type { Project } from "../types";
+import { decodeProjectId } from "./id";
+import { getProjectMeta } from "./getProjectMeta";
+
+export const getProject = async (
+  projectId: string
+): Promise<{ project: Project }> => {
+  const fullPath = decodeProjectId(projectId);
+  if (!existsSync(fullPath)) {
+    throw new Error("Project not found");
+  }
+
+  const meta = await getProjectMeta(fullPath);
+
+  return {
+    project: {
+      id: projectId,
+      claudeProjectPath: fullPath,
+      meta,
+    },
+  };
+};
diff --git a/src/server/service/project/getProjectMeta.ts b/src/server/service/project/getProjectMeta.ts
new file mode 100644
index 0000000..dadbd24
--- /dev/null
+++ b/src/server/service/project/getProjectMeta.ts
@@ -0,0 +1,83 @@
+import { statSync } from "node:fs";
+import { readdir, readFile } from "node:fs/promises";
+import { dirname, resolve } from "node:path";
+
+import { parseJsonl } from "../parseJsonl";
+import type { ProjectMeta } from "../types";
+
+const projectMetaCache = new Map<string, ProjectMeta>();
+
+const extractMetaFromJsonl = async (filePath: string) => {
+  const content = await readFile(filePath, "utf-8");
+  const lines = content.split("\n");
+
+  let cwd: string | null = null;
+
+  for (const line of lines) {
+    const conversation = parseJsonl(line).at(0);
+
+    if (conversation === undefined || conversation.type === "summary") {
+      continue;
+    }
+
+    cwd = conversation.cwd;
+
+    break;
+  }
+
+  return {
+    cwd,
+  } as const;
+};
+
+export const getProjectMeta = async (
+  claudeProjectPath: string
+): Promise<ProjectMeta> => {
+  const cached = projectMetaCache.get(claudeProjectPath);
+  if (cached !== undefined) {
+    return cached;
+  }
+
+  const dirents = await readdir(claudeProjectPath, { withFileTypes: true });
+  const files = dirents
+    .filter((d) => d.isFile() && d.name.endsWith(".jsonl"))
+    .map(
+      (d) =>
+        ({
+          fullPath: resolve(d.parentPath, d.name),
+          stats: statSync(resolve(d.parentPath, d.name)),
+        } as const)
+    )
+    .toSorted((a, b) => {
+      return a.stats.ctime.getTime() - b.stats.ctime.getTime();
+    });
+
+  const lastModifiedUnixTime = files.at(-1)?.stats.ctime.getTime();
+
+  let cwd: string | null = null;
+
+  for (const file of files) {
+    const result = await extractMetaFromJsonl(file.fullPath);
+
+    if (result.cwd === null) {
+      continue;
+    }
+
+    cwd = result.cwd;
+
+    break;
+  }
+
+  const projectMeta: ProjectMeta = {
+    projectName: cwd ? dirname(cwd) : null,
+    projectPath: cwd,
+    lastModifiedAt: lastModifiedUnixTime
+      ? new Date(lastModifiedUnixTime)
+      : null,
+    sessionCount: files.length,
+  };
+
+  projectMetaCache.set(claudeProjectPath, projectMeta);
+
+  return projectMeta;
+};
diff --git a/src/server/service/project/getProjects.ts b/src/server/service/project/getProjects.ts
new file mode 100644
index 0000000..731c5cf
--- /dev/null
+++ b/src/server/service/project/getProjects.ts
@@ -0,0 +1,29 @@
+import { readdir } from "node:fs/promises";
+import { resolve } from "node:path";
+
+import { claudeProjectPath } from "../paths";
+import type { Project } from "../types";
+import { encodeProjectId } from "./id";
+import { getProjectMeta } from "./getProjectMeta";
+
+export const getProjects = async (): Promise<{ projects: Project[] }> => {
+  const dirents = await readdir(claudeProjectPath, { withFileTypes: true });
+  const projects = await Promise.all(
+    dirents
+      .filter((d) => d.isDirectory())
+      .map(async (d) => {
+        const fullPath = resolve(d.parentPath, d.name);
+        const id = encodeProjectId(fullPath);
+
+        return {
+          id,
+          claudeProjectPath: fullPath,
+          meta: await getProjectMeta(fullPath),
+        };
+      })
+  );
+
+  return {
+    projects,
+  };
+};
diff --git a/src/server/service/project/id.ts b/src/server/service/project/id.ts
new file mode 100644
index 0000000..5b9f64c
--- /dev/null
+++ b/src/server/service/project/id.ts
@@ -0,0 +1,7 @@
+export const encodeProjectId = (fullPath: string) => {
+  return Buffer.from(fullPath).toString("base64url");
+};
+
+export const decodeProjectId = (id: string) => {
+  return Buffer.from(id, "base64url").toString("utf-8");
+};
diff --git a/src/server/service/session/getSession.ts b/src/server/service/session/getSession.ts
new file mode 100644
index 0000000..509f078
--- /dev/null
+++ b/src/server/service/session/getSession.ts
@@ -0,0 +1,31 @@
+import { readFile } from "node:fs/promises";
+import { decodeProjectId } from "../project/id";
+import { resolve } from "node:path";
+import { parseJsonl } from "../parseJsonl";
+import type { SessionDetail } from "../types";
+import { getSessionMeta } from "./getSessionMeta";
+
+export const getSession = async (
+  projectId: string,
+  sessionId: string
+): Promise<{
+  session: SessionDetail;
+}> => {
+  const projectPath = decodeProjectId(projectId);
+  const sessionPath = resolve(projectPath, `${sessionId}.jsonl`);
+
+  const content = await readFile(sessionPath, "utf-8");
+
+  const conversations = parseJsonl(content);
+
+  const sessionDetail: SessionDetail = {
+    id: sessionId,
+    jsonlFilePath: sessionPath,
+    meta: await getSessionMeta(sessionPath),
+    conversations,
+  };
+
+  return {
+    session: sessionDetail,
+  };
+};
diff --git a/src/server/service/session/getSessionMeta.ts b/src/server/service/session/getSessionMeta.ts
new file mode 100644
index 0000000..bbc371c
--- /dev/null
+++ b/src/server/service/session/getSessionMeta.ts
@@ -0,0 +1,60 @@
+import { statSync } from "node:fs";
+import { readFile } from "node:fs/promises";
+
+import { parseJsonl } from "../parseJsonl";
+import type { Conversation } from "../../../lib/conversation-schema";
+import type { SessionMeta } from "../types";
+
+const sessionMetaCache = new Map<string, SessionMeta>();
+
+export const getSessionMeta = async (
+  jsonlFilePath: string
+): Promise<SessionMeta> => {
+  const cached = sessionMetaCache.get(jsonlFilePath);
+  if (cached !== undefined) {
+    return cached;
+  }
+
+  const stats = statSync(jsonlFilePath);
+  const lastModifiedUnixTime = stats.ctime.getTime();
+
+  const content = await readFile(jsonlFilePath, "utf-8");
+  const lines = content.split("\n");
+
+  let firstUserMessage: Conversation | null = null;
+
+  for (const line of lines) {
+    const conversation = parseJsonl(line).at(0);
+
+    if (conversation === undefined || conversation.type !== "user") {
+      continue;
+    }
+
+    firstUserMessage = conversation;
+
+    break;
+  }
+
+  const sessionMeta: SessionMeta = {
+    messageCount: lines.length,
+    firstContent:
+      firstUserMessage === null
+        ? null
+        : typeof firstUserMessage.message.content === "string"
+        ? firstUserMessage.message.content
+        : (() => {
+            const firstContent = firstUserMessage.message.content.at(0);
+            if (firstContent === undefined) return null;
+            if (typeof firstContent === "string") return firstContent;
+            if (firstContent.type === "text") return firstContent.text;
+            return null;
+          })(),
+    lastModifiedAt: lastModifiedUnixTime
+      ? new Date(lastModifiedUnixTime)
+      : null,
+  };
+
+  sessionMetaCache.set(jsonlFilePath, sessionMeta);
+
+  return sessionMeta;
+};
diff --git a/src/server/service/session/getSessions.ts b/src/server/service/session/getSessions.ts
new file mode 100644
index 0000000..31e1f72
--- /dev/null
+++ b/src/server/service/session/getSessions.ts
@@ -0,0 +1,31 @@
+import { readdir } from "node:fs/promises";
+import { resolve } from "node:path";
+
+import { decodeProjectId } from "../project/id";
+import type { Session } from "../types";
+import { getSessionMeta } from "./getSessionMeta";
+
+export const getSessions = async (
+  projectId: string
+): Promise<{ sessions: Session[] }> => {
+  const claudeProjectPath = decodeProjectId(projectId);
+
+  const dirents = await readdir(claudeProjectPath, { withFileTypes: true });
+  const sessions = await Promise.all(
+    dirents
+      .filter((d) => d.isFile() && d.name.endsWith(".jsonl"))
+      .map(async (d): Promise<Session> => {
+        const fullPath = resolve(d.parentPath, d.name);
+
+        return {
+          id: d.name,
+          jsonlFilePath: fullPath,
+          meta: await getSessionMeta(fullPath),
+        };
+      })
+  );
+
+  return {
+    sessions,
+  };
+};
diff --git a/src/server/service/types.ts b/src/server/service/types.ts
new file mode 100644
index 0000000..9e120fc
--- /dev/null
+++ b/src/server/service/types.ts
@@ -0,0 +1,30 @@
+import type { Conversation } from "../../lib/conversation-schema";
+
+export type Project = {
+  id: string;
+  claudeProjectPath: string;
+  meta: ProjectMeta;
+};
+
+export type ProjectMeta = {
+  projectName: string | null;
+  projectPath: string | null;
+  lastModifiedAt: Date | null;
+  sessionCount: number;
+};
+
+export type Session = {
+  id: string;
+  jsonlFilePath: string;
+  meta: SessionMeta;
+};
+
+export type SessionMeta = {
+  messageCount: number;
+  firstContent: string | null;
+  lastModifiedAt: Date | null;
+};
+
+export type SessionDetail = Session & {
+  conversations: Conversation[];
+};
diff --git a/tsconfig.json b/tsconfig.json
index 37ffbcc..ed4ef0a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,7 @@
   "extends": "@tsconfig/strictest/tsconfig.json",
   "compilerOptions": {
     // transpile target
-    "target": "ES2017",
+    "target": "ES2020",
     "lib": ["dom", "dom.iterable", "esnext"],
     "noEmit": true,
     // module