diff --git a/packages/opencode/src/cli/cmd/session.ts b/packages/opencode/src/cli/cmd/session.ts
index 7fb5fda97b9..c26e6290e8a 100644
--- a/packages/opencode/src/cli/cmd/session.ts
+++ b/packages/opencode/src/cli/cmd/session.ts
@@ -73,6 +73,11 @@ export const SessionListCommand = cmd({
   describe: "list sessions",
   builder: (yargs: Argv) => {
     return yargs
+      .option("all", {
+        alias: "a",
+        describe: "list sessions across all projects",
+        type: "boolean",
+      })
       .option("max-count", {
         alias: "n",
         describe: "limit to N most recent sessions",
@@ -87,7 +92,9 @@ export const SessionListCommand = cmd({
   },
   handler: async (args) => {
     await bootstrap(process.cwd(), async () => {
-      const sessions = [...Session.list({ roots: true, limit: args.maxCount })]
+      const sessions = args.all
+        ? [...Session.listGlobal({ roots: true, limit: args.maxCount })]
+        : [...Session.list({ roots: true, limit: args.maxCount })]
 
       if (sessions.length === 0) {
         return
@@ -97,7 +104,7 @@ export const SessionListCommand = cmd({
       if (args.format === "json") {
         output = formatSessionJSON(sessions)
       } else {
-        output = formatSessionTable(sessions)
+        output = formatSessionTable(sessions, args.all)
       }
 
       const shouldPaginate = process.stdout.isTTY && !args.maxCount && args.format === "table"
@@ -124,26 +131,31 @@ export const SessionListCommand = cmd({
   },
 })
 
-function formatSessionTable(sessions: Session.Info[]): string {
+export function formatSessionTable(sessions: Session.Info[], all?: boolean): string {
   const lines: string[] = []
 
   const maxIdWidth = Math.max(20, ...sessions.map((s) => s.id.length))
+  const maxProjectWidth = all ? Math.max(10, ...sessions.map((s) => s.projectID.length)) : 10
   const maxTitleWidth = Math.max(25, ...sessions.map((s) => s.title.length))
 
-  const header = `Session ID${" ".repeat(maxIdWidth - 10)}  Title${" ".repeat(maxTitleWidth - 5)}  Updated`
+  const header = all
+    ? `Session ID${" ".repeat(maxIdWidth - 10)}  Project ID${" ".repeat(maxProjectWidth - 10)}  Title${" ".repeat(maxTitleWidth - 5)}  Updated`
+    : `Session ID${" ".repeat(maxIdWidth - 10)}  Title${" ".repeat(maxTitleWidth - 5)}  Updated`
   lines.push(header)
   lines.push("─".repeat(header.length))
   for (const session of sessions) {
     const truncatedTitle = Locale.truncate(session.title, maxTitleWidth)
     const timeStr = Locale.todayTimeOrDateTime(session.time.updated)
-    const line = `${session.id.padEnd(maxIdWidth)}  ${truncatedTitle.padEnd(maxTitleWidth)}  ${timeStr}`
+    const line = all
+      ? `${session.id.padEnd(maxIdWidth)}  ${session.projectID.padEnd(maxProjectWidth)}  ${truncatedTitle.padEnd(maxTitleWidth)}  ${timeStr}`
+      : `${session.id.padEnd(maxIdWidth)}  ${truncatedTitle.padEnd(maxTitleWidth)}  ${timeStr}`
     lines.push(line)
   }
 
   return lines.join(EOL)
 }
 
-function formatSessionJSON(sessions: Session.Info[]): string {
+export function formatSessionJSON(sessions: Session.Info[]): string {
   const jsonData = sessions.map((session) => ({
     id: session.id,
     title: session.title,
diff --git a/packages/opencode/test/cli/session-list.test.ts b/packages/opencode/test/cli/session-list.test.ts
new file mode 100644
index 00000000000..4620c0843ce
--- /dev/null
+++ b/packages/opencode/test/cli/session-list.test.ts
@@ -0,0 +1,70 @@
+import { describe, expect, test } from "bun:test"
+import { formatSessionJSON, formatSessionTable } from "../../src/cli/cmd/session"
+import type { Session } from "../../src/session"
+
+function buildSession(input: { id: string; projectID: string; title: string; updated: number }): Session.Info {
+  return {
+    id: input.id,
+    slug: "test-slug",
+    projectID: input.projectID,
+    directory: "/tmp/project",
+    title: input.title,
+    version: "1.0.0",
+    time: {
+      created: input.updated,
+      updated: input.updated,
+    },
+  }
+}
+
+describe("session list formatting", () => {
+  test("shows Project ID column for all sessions table", () => {
+    const sessions = [
+      buildSession({
+        id: "ses_1",
+        projectID: "proj_1",
+        title: "Session One",
+        updated: 1710000000000,
+      }),
+    ]
+
+    const output = formatSessionTable(sessions, true)
+    const lines = output.split("\n")
+
+    expect(lines[0]).toContain("Project ID")
+    expect(lines[2]).toContain("proj_1")
+  })
+
+  test("hides Project ID column for default table", () => {
+    const sessions = [
+      buildSession({
+        id: "ses_1",
+        projectID: "proj_1",
+        title: "Session One",
+        updated: 1710000000000,
+      }),
+    ]
+
+    const output = formatSessionTable(sessions)
+    const lines = output.split("\n")
+
+    expect(lines[0]).not.toContain("Project ID")
+    expect(lines[2]).not.toContain("proj_1")
+  })
+
+  test("json output includes project id", () => {
+    const sessions = [
+      buildSession({
+        id: "ses_1",
+        projectID: "proj_1",
+        title: "Session One",
+        updated: 1710000000000,
+      }),
+    ]
+
+    const output = formatSessionJSON(sessions)
+    const parsed = JSON.parse(output) as { projectId: string }[]
+
+    expect(parsed[0].projectId).toBe("proj_1")
+  })
+})
diff --git a/packages/opencode/test/server/global-session-list.test.ts b/packages/opencode/test/server/global-session-list.test.ts
index 05d6de04b1b..7e3aef1beeb 100644
--- a/packages/opencode/test/server/global-session-list.test.ts
+++ b/packages/opencode/test/server/global-session-list.test.ts
@@ -86,4 +86,29 @@ describe("Session.listGlobal", () => {
     expect(ids).toContain(first.id)
     expect(ids).not.toContain(second.id)
   })
+
+  test("filters root sessions across projects", async () => {
+    await using first = await tmpdir({ git: true })
+    await using second = await tmpdir({ git: true })
+
+    const root = await Instance.provide({
+      directory: first.path,
+      fn: async () => Session.create({ title: "root-session" }),
+    })
+    const child = await Instance.provide({
+      directory: first.path,
+      fn: async () => Session.create({ title: "child-session", parentID: root.id }),
+    })
+    const otherRoot = await Instance.provide({
+      directory: second.path,
+      fn: async () => Session.create({ title: "other-root-session" }),
+    })
+
+    const sessions = [...Session.listGlobal({ roots: true, limit: 200 })]
+    const ids = sessions.map((session) => session.id)
+
+    expect(ids).toContain(root.id)
+    expect(ids).toContain(otherRoot.id)
+    expect(ids).not.toContain(child.id)
+  })
 })