feat(id): brand SessionID through Drizzle and Zod schemas (#16953)

2026-04-01 23:02:26 +00:00 · 2026-03-11 19:16:56 -04:00
parent 4e73473119
commit cb67465675
44 changed files with 226 additions and 158 deletions
--- a/packages/opencode/src/cli/cmd/export.ts
+++ b/packages/opencode/src/cli/cmd/export.ts
@@ -1,5 +1,6 @@
 import type { Argv } from "yargs"
 import { Session } from "../../session"
+import { SessionID } from "../../session/schema"
 import { cmd } from "./cmd"
 import { bootstrap } from "../bootstrap"
 import { UI } from "../ui"
@@ -17,7 +18,7 @@ export const ExportCommand = cmd({
  },
  handler: async (args) => {
    await bootstrap(process.cwd(), async () => {
-      let sessionID = args.sessionID
+      let sessionID = args.sessionID ? SessionID.make(args.sessionID) : undefined
      process.stderr.write(`Exporting session: ${sessionID ?? "latest"}\n`)

      if (!sessionID) {
@@ -58,7 +59,7 @@ export const ExportCommand = cmd({
          throw new UI.CancelledError()
        }

-        sessionID = selectedSession as string
+        sessionID = selectedSession

        prompts.outro("Exporting session...", {
          output: process.stderr,
@@ -67,7 +68,7 @@ export const ExportCommand = cmd({

      try {
        const sessionInfo = await Session.get(sessionID!)
-        const messages = await Session.messages({ sessionID: sessionID! })
+        const messages = await Session.messages({ sessionID: sessionInfo.id })

        const exportData = {
          info: sessionInfo,
--- a/packages/opencode/src/cli/cmd/github.ts
+++ b/packages/opencode/src/cli/cmd/github.ts
@@ -22,6 +22,7 @@ import { ModelsDev } from "../../provider/models"
 import { Instance } from "@/project/instance"
 import { bootstrap } from "../bootstrap"
 import { Session } from "../../session"
+import type { SessionID } from "../../session/schema"
 import { Identifier } from "../../id/id"
 import { Provider } from "../../provider/provider"
 import { Bus } from "../../bus"
@@ -481,7 +482,7 @@ export const GithubRunCommand = cmd({
      let octoRest: Octokit
      let octoGraph: typeof graphql
      let gitConfig: string
-      let session: { id: string; title: string; version: string }
+      let session: { id: SessionID; title: string; version: string }
      let shareId: string | undefined
      let exitCode = 0
      type PromptFiles = Awaited<ReturnType<typeof getUserPrompt>>["promptFiles"]
--- a/packages/opencode/src/cli/cmd/import.ts
+++ b/packages/opencode/src/cli/cmd/import.ts
@@ -1,6 +1,7 @@
 import type { Argv } from "yargs"
 import type { Session as SDKSession, Message, Part } from "@opencode-ai/sdk/v2"
 import { Session } from "../../session"
+import { SessionID } from "../../session/schema"
 import { cmd } from "./cmd"
 import { bootstrap } from "../bootstrap"
 import { Database } from "../../storage/db"
@@ -152,7 +153,12 @@ export const ImportCommand = cmd({
        return
      }

-      const row = Session.toRow({ ...exportData.info, projectID: Instance.project.id })
+      const row = Session.toRow({
+        ...exportData.info,
+        id: SessionID.make(exportData.info.id),
+        parentID: exportData.info.parentID ? SessionID.make(exportData.info.parentID) : undefined,
+        projectID: Instance.project.id,
+      })
      Database.use((db) =>
        db
          .insert(SessionTable)
@@ -167,7 +173,7 @@ export const ImportCommand = cmd({
            .insert(MessageTable)
            .values({
              id: msg.info.id,
-              session_id: exportData.info.id,
+              session_id: row.id,
              time_created: msg.info.time?.created ?? Date.now(),
              data: msg.info,
            })
@@ -182,7 +188,7 @@ export const ImportCommand = cmd({
              .values({
                id: part.id,
                message_id: msg.info.id,
-                session_id: exportData.info.id,
+                session_id: row.id,
                data: part,
              })
              .onConflictDoNothing()
--- a/packages/opencode/src/cli/cmd/session.ts
+++ b/packages/opencode/src/cli/cmd/session.ts
@@ -1,6 +1,7 @@
 import type { Argv } from "yargs"
 import { cmd } from "./cmd"
 import { Session } from "../../session"
+import { SessionID } from "../../session/schema"
 import { bootstrap } from "../bootstrap"
 import { UI } from "../ui"
 import { Locale } from "../../util/locale"
@@ -57,13 +58,14 @@ export const SessionDeleteCommand = cmd({
  },
  handler: async (args) => {
    await bootstrap(process.cwd(), async () => {
+      const sessionID = SessionID.make(args.sessionID)
      try {
-        await Session.get(args.sessionID)
+        await Session.get(sessionID)
      } catch {
        UI.error(`Session not found: ${args.sessionID}`)
        process.exit(1)
      }
-      await Session.remove(args.sessionID)
+      await Session.remove(sessionID)
      UI.println(UI.Style.TEXT_SUCCESS_BOLD + `Session ${args.sessionID} deleted` + UI.Style.TEXT_NORMAL)
    })
  },
--- a/packages/opencode/src/cli/cmd/tui/event.ts
+++ b/packages/opencode/src/cli/cmd/tui/event.ts
@@ -1,5 +1,6 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
+import { SessionID } from "@/session/schema"
 import z from "zod"

 export const TuiEvent = {
@@ -42,7 +43,7 @@ export const TuiEvent = {
  SessionSelect: BusEvent.define(
    "tui.session.select",
    z.object({
-      sessionID: z.string().regex(/^ses/).describe("Session ID to navigate to"),
+      sessionID: SessionID.zod.describe("Session ID to navigate to"),
    }),
  ),
 }
--- a/packages/opencode/src/command/index.ts
+++ b/packages/opencode/src/command/index.ts
@@ -1,4 +1,5 @@
 import { BusEvent } from "@/bus/bus-event"
+import { SessionID } from "@/session/schema"
 import z from "zod"
 import { Config } from "../config/config"
 import { Instance } from "../project/instance"
@@ -14,7 +15,7 @@ export namespace Command {
      "command.executed",
      z.object({
        name: z.string(),
-        sessionID: Identifier.schema("session"),
+        sessionID: SessionID.zod,
        arguments: z.string(),
        messageID: Identifier.schema("message"),
      }),
--- a/packages/opencode/src/permission/index.ts
+++ b/packages/opencode/src/permission/index.ts
@@ -1,5 +1,6 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
+import { SessionID } from "@/session/schema"
 import z from "zod"
 import { Log } from "../util/log"
 import { Identifier } from "../id/id"
@@ -24,7 +25,7 @@ export namespace Permission {
      id: z.string(),
      type: z.string(),
      pattern: z.union([z.string(), z.array(z.string())]).optional(),
-      sessionID: z.string(),
+      sessionID: SessionID.zod,
      messageID: z.string(),
      callID: z.string().optional(),
      message: z.string(),
@@ -43,7 +44,7 @@ export namespace Permission {
    Replied: BusEvent.define(
      "permission.replied",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        permissionID: z.string(),
        response: z.string(),
      }),
--- a/packages/opencode/src/permission/next.ts
+++ b/packages/opencode/src/permission/next.ts
@@ -2,6 +2,7 @@ import { Bus } from "@/bus"
 import { BusEvent } from "@/bus/bus-event"
 import { Config } from "@/config/config"
 import { Identifier } from "@/id/id"
+import { SessionID } from "@/session/schema"
 import { Instance } from "@/project/instance"
 import { Database, eq } from "@/storage/db"
 import { PermissionTable } from "@/session/session.sql"
@@ -69,7 +70,7 @@ export namespace PermissionNext {
  export const Request = z
    .object({
      id: Identifier.schema("permission"),
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      permission: z.string(),
      patterns: z.string().array(),
      metadata: z.record(z.string(), z.any()),
@@ -100,7 +101,7 @@ export namespace PermissionNext {
    Replied: BusEvent.define(
      "permission.replied",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        requestID: z.string(),
        reply: Reply,
      }),
--- a/packages/opencode/src/question/index.ts
+++ b/packages/opencode/src/question/index.ts
@@ -1,6 +1,7 @@
 import { Bus } from "@/bus"
 import { BusEvent } from "@/bus/bus-event"
 import { Identifier } from "@/id/id"
+import { SessionID } from "@/session/schema"
 import { Instance } from "@/project/instance"
 import { Log } from "@/util/log"
 import z from "zod"
@@ -34,7 +35,7 @@ export namespace Question {
  export const Request = z
    .object({
      id: Identifier.schema("question"),
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      questions: z.array(Info).describe("Questions to ask"),
      tool: z
        .object({
@@ -65,7 +66,7 @@ export namespace Question {
    Replied: BusEvent.define(
      "question.replied",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        requestID: z.string(),
        answers: z.array(Answer),
      }),
@@ -73,7 +74,7 @@ export namespace Question {
    Rejected: BusEvent.define(
      "question.rejected",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        requestID: z.string(),
      }),
    ),
@@ -95,7 +96,7 @@ export namespace Question {
  })

  export async function ask(input: {
-    sessionID: string
+    sessionID: SessionID
    questions: Info[]
    tool?: { messageID: string; callID: string }
  }): Promise<Answer[]> {
--- a/packages/opencode/src/server/routes/session.ts
+++ b/packages/opencode/src/server/routes/session.ts
@@ -1,6 +1,7 @@
 import { Hono } from "hono"
 import { stream } from "hono/streaming"
 import { describeRoute, validator, resolver } from "hono-openapi"
+import { SessionID } from "@/session/schema"
 import z from "zod"
 import { Session } from "../../session"
 import { MessageV2 } from "../../session/message-v2"
@@ -173,7 +174,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      async (c) => {
@@ -258,7 +259,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
        }),
      ),
      validator(
@@ -309,7 +310,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", Session.initialize.schema.omit({ sessionID: true })),
@@ -372,7 +373,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
        }),
      ),
      async (c) => {
@@ -401,7 +402,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
        }),
      ),
      async (c) => {
@@ -502,7 +503,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator(
@@ -561,7 +562,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator(
@@ -605,7 +606,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
          messageID: z.string().meta({ description: "Message ID" }),
        }),
      ),
@@ -640,7 +641,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
          messageID: z.string().meta({ description: "Message ID" }),
        }),
      ),
@@ -674,7 +675,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
          messageID: z.string().meta({ description: "Message ID" }),
          partID: z.string().meta({ description: "Part ID" }),
        }),
@@ -709,7 +710,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
          messageID: z.string().meta({ description: "Message ID" }),
          partID: z.string().meta({ description: "Part ID" }),
        }),
@@ -753,7 +754,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
@@ -785,7 +786,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
@@ -825,7 +826,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", SessionPrompt.CommandInput.omit({ sessionID: true })),
@@ -857,7 +858,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string().meta({ description: "Session ID" }),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", SessionPrompt.ShellInput.omit({ sessionID: true })),
@@ -889,7 +890,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
        }),
      ),
      validator("json", SessionRevert.RevertInput.omit({ sessionID: true })),
@@ -924,7 +925,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
        }),
      ),
      async (c) => {
@@ -955,7 +956,7 @@ export const SessionRoutes = lazy(() =>
      validator(
        "param",
        z.object({
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
          permissionID: z.string(),
        }),
      ),
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -2,6 +2,7 @@ import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
 import { Session } from "."
 import { Identifier } from "../id/id"
+import { SessionID } from "./schema"
 import { Instance } from "../project/instance"
 import { Provider } from "../provider/provider"
 import { MessageV2 } from "./message-v2"
@@ -22,7 +23,7 @@ export namespace SessionCompaction {
    Compacted: BusEvent.define(
      "session.compacted",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
      }),
    ),
  }
@@ -55,7 +56,7 @@ export namespace SessionCompaction {
  // goes backwards through parts until there are 40_000 tokens worth of tool
  // calls. then erases output of previous tool calls. idea is to throw away old
  // tool calls that are no longer relevant.
-  export async function prune(input: { sessionID: string }) {
+  export async function prune(input: { sessionID: SessionID }) {
    const config = await Config.get()
    if (config.compaction?.prune === false) return
    log.info("pruning")
@@ -101,7 +102,7 @@ export namespace SessionCompaction {
  export async function process(input: {
    parentID: string
    messages: MessageV2.WithParts[]
-    sessionID: string
+    sessionID: SessionID
    abort: AbortSignal
    auto: boolean
    overflow?: boolean
@@ -295,7 +296,7 @@ When constructing the summary, try to stick to this template:

  export const create = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      agent: z.string(),
      model: z.object({
        providerID: z.string(),
--- a/packages/opencode/src/session/index.ts
+++ b/packages/opencode/src/session/index.ts
@@ -24,6 +24,7 @@ import { Command } from "../command"
 import { Snapshot } from "@/snapshot"
 import { WorkspaceContext } from "../control-plane/workspace-context"
 import { ProjectID } from "../project/schema"
+import { SessionID } from "./schema"

 import type { Provider } from "@/provider/provider"
 import { PermissionNext } from "@/permission/next"
@@ -119,12 +120,12 @@ export namespace Session {

  export const Info = z
    .object({
-      id: Identifier.schema("session"),
+      id: SessionID.zod,
      slug: z.string(),
      projectID: ProjectID.zod,
      workspaceID: z.string().optional(),
      directory: z.string(),
-      parentID: Identifier.schema("session").optional(),
+      parentID: SessionID.zod.optional(),
      summary: z
        .object({
          additions: z.number(),
@@ -201,14 +202,14 @@ export namespace Session {
    Diff: BusEvent.define(
      "session.diff",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        diff: Snapshot.FileDiff.array(),
      }),
    ),
    Error: BusEvent.define(
      "session.error",
      z.object({
-        sessionID: z.string().optional(),
+        sessionID: SessionID.zod.optional(),
        error: MessageV2.Assistant.shape.error,
      }),
    ),
@@ -217,7 +218,7 @@ export namespace Session {
  export const create = fn(
    z
      .object({
-        parentID: Identifier.schema("session").optional(),
+        parentID: SessionID.zod.optional(),
        title: z.string().optional(),
        permission: Info.shape.permission,
        workspaceID: Identifier.schema("workspace").optional(),
@@ -236,7 +237,7 @@ export namespace Session {

  export const fork = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      messageID: Identifier.schema("message").optional(),
    }),
    async (input) => {
@@ -277,7 +278,7 @@ export namespace Session {
    },
  )

-  export const touch = fn(Identifier.schema("session"), async (sessionID) => {
+  export const touch = fn(SessionID.zod, async (sessionID) => {
    const now = Date.now()
    Database.use((db) => {
      const row = db
@@ -293,15 +294,15 @@ export namespace Session {
  })

  export async function createNext(input: {
-    id?: string
+    id?: SessionID
    title?: string
-    parentID?: string
+    parentID?: SessionID
    workspaceID?: string
    directory: string
    permission?: PermissionNext.Ruleset
  }) {
    const result: Info = {
-      id: Identifier.descending("session", input.id),
+      id: SessionID.descending(input.id),
      slug: Slug.create(),
      version: Installation.VERSION,
      projectID: Instance.project.id,
@@ -342,13 +343,13 @@ export namespace Session {
    return path.join(base, [input.time.created, input.slug].join("-") + ".md")
  }

-  export const get = fn(Identifier.schema("session"), async (id) => {
+  export const get = fn(SessionID.zod, async (id) => {
    const row = Database.use((db) => db.select().from(SessionTable).where(eq(SessionTable.id, id)).get())
    if (!row) throw new NotFoundError({ message: `Session not found: ${id}` })
    return fromRow(row)
  })

-  export const share = fn(Identifier.schema("session"), async (id) => {
+  export const share = fn(SessionID.zod, async (id) => {
    const cfg = await Config.get()
    if (cfg.share === "disabled") {
      throw new Error("Sharing is disabled in configuration")
@@ -364,7 +365,7 @@ export namespace Session {
    return share
  })

-  export const unshare = fn(Identifier.schema("session"), async (id) => {
+  export const unshare = fn(SessionID.zod, async (id) => {
    // Use ShareNext to remove the share (same as share function uses ShareNext to create)
    const { ShareNext } = await import("@/share/share-next")
    await ShareNext.remove(id)
@@ -378,7 +379,7 @@ export namespace Session {

  export const setTitle = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      title: z.string(),
    }),
    async (input) => {
@@ -399,7 +400,7 @@ export namespace Session {

  export const setArchived = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      time: z.number().optional(),
    }),
    async (input) => {
@@ -420,7 +421,7 @@ export namespace Session {

  export const setPermission = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      permission: PermissionNext.Ruleset,
    }),
    async (input) => {
@@ -441,7 +442,7 @@ export namespace Session {

  export const setRevert = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      revert: Info.shape.revert,
      summary: Info.shape.summary,
    }),
@@ -467,7 +468,7 @@ export namespace Session {
    },
  )

-  export const clearRevert = fn(Identifier.schema("session"), async (sessionID) => {
+  export const clearRevert = fn(SessionID.zod, async (sessionID) => {
    return Database.use((db) => {
      const row = db
        .update(SessionTable)
@@ -487,7 +488,7 @@ export namespace Session {

  export const setSummary = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      summary: Info.shape.summary,
    }),
    async (input) => {
@@ -511,7 +512,7 @@ export namespace Session {
    },
  )

-  export const diff = fn(Identifier.schema("session"), async (sessionID) => {
+  export const diff = fn(SessionID.zod, async (sessionID) => {
    try {
      return await Storage.read<Snapshot.FileDiff[]>(["session_diff", sessionID])
    } catch {
@@ -521,7 +522,7 @@ export namespace Session {

  export const messages = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      limit: z.number().optional(),
    }),
    async (input) => {
@@ -647,7 +648,7 @@ export namespace Session {
    }
  }

-  export const children = fn(Identifier.schema("session"), async (parentID) => {
+  export const children = fn(SessionID.zod, async (parentID) => {
    const project = Instance.project
    const rows = Database.use((db) =>
      db
@@ -659,7 +660,7 @@ export namespace Session {
    return rows.map(fromRow)
  })

-  export const remove = fn(Identifier.schema("session"), async (sessionID) => {
+  export const remove = fn(SessionID.zod, async (sessionID) => {
    const project = Instance.project
    try {
      const session = await get(sessionID)
@@ -705,7 +706,7 @@ export namespace Session {

  export const removeMessage = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      messageID: Identifier.schema("message"),
    }),
    async (input) => {
@@ -727,7 +728,7 @@ export namespace Session {

  export const removePart = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      messageID: Identifier.schema("message"),
      partID: Identifier.schema("part"),
    }),
@@ -775,7 +776,7 @@ export namespace Session {

  export const updatePartDelta = fn(
    z.object({
-      sessionID: z.string(),
+      sessionID: SessionID.zod,
      messageID: z.string(),
      partID: z.string(),
      field: z.string(),
@@ -873,7 +874,7 @@ export namespace Session {

  export const initialize = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      modelID: z.string(),
      providerID: z.string(),
      messageID: Identifier.schema("message"),
--- a/packages/opencode/src/session/message-v2.ts
+++ b/packages/opencode/src/session/message-v2.ts
@@ -1,4 +1,5 @@
 import { BusEvent } from "@/bus/bus-event"
+import { SessionID } from "./schema"
 import z from "zod"
 import { NamedError } from "@opencode-ai/util/error"
 import { APICallError, convertToModelMessages, LoadAPIKeyError, type ModelMessage, type UIMessage } from "ai"
@@ -79,7 +80,7 @@ export namespace MessageV2 {

  const PartBase = z.object({
    id: z.string(),
-    sessionID: z.string(),
+    sessionID: SessionID.zod,
    messageID: z.string(),
  })

@@ -344,7 +345,7 @@ export namespace MessageV2 {

  const Base = z.object({
    id: z.string(),
-    sessionID: z.string(),
+    sessionID: SessionID.zod,
  })

  export const User = Base.extend({
@@ -457,7 +458,7 @@ export namespace MessageV2 {
    Removed: BusEvent.define(
      "message.removed",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        messageID: z.string(),
      }),
    ),
@@ -470,7 +471,7 @@ export namespace MessageV2 {
    PartDelta: BusEvent.define(
      "message.part.delta",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        messageID: z.string(),
        partID: z.string(),
        field: z.string(),
@@ -480,7 +481,7 @@ export namespace MessageV2 {
    PartRemoved: BusEvent.define(
      "message.part.removed",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        messageID: z.string(),
        partID: z.string(),
      }),
@@ -728,7 +729,7 @@ export namespace MessageV2 {
    )
  }

-  export const stream = fn(Identifier.schema("session"), async function* (sessionID) {
+  export const stream = fn(SessionID.zod, async function* (sessionID) {
    const size = 50
    let offset = 0
    while (true) {
@@ -792,7 +793,7 @@ export namespace MessageV2 {

  export const get = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      messageID: Identifier.schema("message"),
    }),
    async (input): Promise<WithParts> => {
--- a/packages/opencode/src/session/message.ts
+++ b/packages/opencode/src/session/message.ts
@@ -1,4 +1,5 @@
 import z from "zod"
+import { SessionID } from "./schema"
 import { NamedError } from "@opencode-ai/util/error"

 export namespace Message {
@@ -142,7 +143,7 @@ export namespace Message {
          error: z
            .discriminatedUnion("name", [AuthError.Schema, NamedError.Unknown.Schema, OutputLengthError.Schema])
            .optional(),
-          sessionID: z.string(),
+          sessionID: SessionID.zod,
          tool: z.record(
            z.string(),
            z
--- a/packages/opencode/src/session/processor.ts
+++ b/packages/opencode/src/session/processor.ts
@@ -15,6 +15,7 @@ import { Config } from "@/config/config"
 import { SessionCompaction } from "./compaction"
 import { PermissionNext } from "@/permission/next"
 import { Question } from "@/question"
+import type { SessionID } from "./schema"

 export namespace SessionProcessor {
  const DOOM_LOOP_THRESHOLD = 3
@@ -25,7 +26,7 @@ export namespace SessionProcessor {

  export function create(input: {
    assistantMessage: MessageV2.Assistant
-    sessionID: string
+    sessionID: SessionID
    model: Provider.Model
    abort: AbortSignal
  }) {
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -4,6 +4,7 @@ import fs from "fs/promises"
 import z from "zod"
 import { Filesystem } from "../util/filesystem"
 import { Identifier } from "../id/id"
+import { SessionID } from "./schema"
 import { MessageV2 } from "./message-v2"
 import { Log } from "../util/log"
 import { SessionRevert } from "./revert"
@@ -84,13 +85,13 @@ export namespace SessionPrompt {
    },
  )

-  export function assertNotBusy(sessionID: string) {
+  export function assertNotBusy(sessionID: SessionID) {
    const match = state()[sessionID]
    if (match) throw new Session.BusyError(sessionID)
  }

  export const PromptInput = z.object({
-    sessionID: Identifier.schema("session"),
+    sessionID: SessionID.zod,
    messageID: Identifier.schema("message").optional(),
    model: z
      .object({
@@ -254,7 +255,7 @@ export namespace SessionPrompt {
    return s[sessionID].abort.signal
  }

-  export function cancel(sessionID: string) {
+  export function cancel(sessionID: SessionID) {
    log.info("cancel", { sessionID })
    const s = state()
    const match = s[sessionID]
@@ -269,7 +270,7 @@ export namespace SessionPrompt {
  }

  export const LoopInput = z.object({
-    sessionID: Identifier.schema("session"),
+    sessionID: SessionID.zod,
    resume_existing: z.boolean().optional(),
  })
  export const loop = fn(LoopInput, async (input) => {
@@ -731,7 +732,7 @@ export namespace SessionPrompt {
    throw new Error("Impossible")
  })

-  async function lastModel(sessionID: string) {
+  async function lastModel(sessionID: SessionID) {
    for await (const item of MessageV2.stream(sessionID)) {
      if (item.info.role === "user" && item.info.model) return item.info.model
    }
@@ -1467,7 +1468,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
  }

  export const ShellInput = z.object({
-    sessionID: Identifier.schema("session"),
+    sessionID: SessionID.zod,
    agent: z.string(),
    model: z
      .object({
@@ -1719,7 +1720,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the

  export const CommandInput = z.object({
    messageID: Identifier.schema("message").optional(),
-    sessionID: Identifier.schema("session"),
+    sessionID: SessionID.zod,
    agent: z.string().optional(),
    model: z.string().optional(),
    arguments: z.string(),
--- a/packages/opencode/src/session/revert.ts
+++ b/packages/opencode/src/session/revert.ts
@@ -1,5 +1,6 @@
 import z from "zod"
 import { Identifier } from "../id/id"
+import { SessionID } from "./schema"
 import { Snapshot } from "../snapshot"
 import { MessageV2 } from "./message-v2"
 import { Session } from "."
@@ -15,7 +16,7 @@ export namespace SessionRevert {
  const log = Log.create({ service: "session.revert" })

  export const RevertInput = z.object({
-    sessionID: Identifier.schema("session"),
+    sessionID: SessionID.zod,
    messageID: Identifier.schema("message"),
    partID: Identifier.schema("part").optional(),
  })
@@ -79,7 +80,7 @@ export namespace SessionRevert {
    return session
  }

-  export async function unrevert(input: { sessionID: string }) {
+  export async function unrevert(input: { sessionID: SessionID }) {
    log.info("unreverting", input)
    SessionPrompt.assertNotBusy(input.sessionID)
    const session = await Session.get(input.sessionID)
--- a/packages/opencode/src/session/schema.ts
+++ b/packages/opencode/src/session/schema.ts
@@ -0,0 +1,17 @@
+import { Schema } from "effect"
+import z from "zod"
+
+import { withStatics } from "@/util/schema"
+import { Identifier } from "@/id/id"
+
+const sessionIdSchema = Schema.String.pipe(Schema.brand("SessionId"))
+
+export type SessionID = typeof sessionIdSchema.Type
+
+export const SessionID = sessionIdSchema.pipe(
+  withStatics((schema: typeof sessionIdSchema) => ({
+    make: (id: string) => schema.makeUnsafe(id),
+    descending: (id?: string) => schema.makeUnsafe(Identifier.descending("session", id)),
+    zod: z.string().startsWith("ses").pipe(z.custom<SessionID>()),
+  })),
+)
--- a/packages/opencode/src/session/session.sql.ts
+++ b/packages/opencode/src/session/session.sql.ts
@@ -4,6 +4,7 @@ import type { MessageV2 } from "./message-v2"
 import type { Snapshot } from "../snapshot"
 import type { PermissionNext } from "../permission/next"
 import type { ProjectID } from "../project/schema"
+import type { SessionID } from "./schema"
 import { Timestamps } from "../storage/schema.sql"

 type PartData = Omit<MessageV2.Part, "id" | "sessionID" | "messageID">
@@ -12,13 +13,13 @@ type InfoData = Omit<MessageV2.Info, "id" | "sessionID">
 export const SessionTable = sqliteTable(
  "session",
  {
-    id: text().primaryKey(),
+    id: text().$type<SessionID>().primaryKey(),
    project_id: text()
      .$type<ProjectID>()
      .notNull()
      .references(() => ProjectTable.id, { onDelete: "cascade" }),
    workspace_id: text(),
-    parent_id: text(),
+    parent_id: text().$type<SessionID>(),
    slug: text().notNull(),
    directory: text().notNull(),
    title: text().notNull(),
@@ -46,6 +47,7 @@ export const MessageTable = sqliteTable(
  {
    id: text().primaryKey(),
    session_id: text()
+      .$type<SessionID>()
      .notNull()
      .references(() => SessionTable.id, { onDelete: "cascade" }),
    ...Timestamps,
@@ -61,7 +63,7 @@ export const PartTable = sqliteTable(
    message_id: text()
      .notNull()
      .references(() => MessageTable.id, { onDelete: "cascade" }),
-    session_id: text().notNull(),
+    session_id: text().$type<SessionID>().notNull(),
    ...Timestamps,
    data: text({ mode: "json" }).notNull().$type<PartData>(),
  },
@@ -72,6 +74,7 @@ export const TodoTable = sqliteTable(
  "todo",
  {
    session_id: text()
+      .$type<SessionID>()
      .notNull()
      .references(() => SessionTable.id, { onDelete: "cascade" }),
    content: text().notNull(),
--- a/packages/opencode/src/session/status.ts
+++ b/packages/opencode/src/session/status.ts
@@ -1,6 +1,7 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
 import { Instance } from "@/project/instance"
+import { SessionID } from "./schema"
 import z from "zod"

 export namespace SessionStatus {
@@ -28,7 +29,7 @@ export namespace SessionStatus {
    Status: BusEvent.define(
      "session.status",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        status: Info,
      }),
    ),
@@ -36,7 +37,7 @@ export namespace SessionStatus {
    Idle: BusEvent.define(
      "session.idle",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
      }),
    ),
  }
@@ -46,7 +47,7 @@ export namespace SessionStatus {
    return data
  })

-  export function get(sessionID: string) {
+  export function get(sessionID: SessionID) {
    return (
      state()[sessionID] ?? {
        type: "idle",
@@ -58,7 +59,7 @@ export namespace SessionStatus {
    return state()
  }

-  export function set(sessionID: string, status: Info) {
+  export function set(sessionID: SessionID, status: Info) {
    Bus.publish(Event.Status, {
      sessionID,
      status,
--- a/packages/opencode/src/session/summary.ts
+++ b/packages/opencode/src/session/summary.ts
@@ -4,6 +4,7 @@ import { Session } from "."

 import { MessageV2 } from "./message-v2"
 import { Identifier } from "@/id/id"
+import { SessionID } from "./schema"
 import { Snapshot } from "@/snapshot"

 import { Storage } from "@/storage/storage"
@@ -68,7 +69,7 @@ export namespace SessionSummary {

  export const summarize = fn(
    z.object({
-      sessionID: z.string(),
+      sessionID: SessionID.zod,
      messageID: z.string(),
    }),
    async (input) => {
@@ -80,7 +81,7 @@ export namespace SessionSummary {
    },
  )

-  async function summarizeSession(input: { sessionID: string; messages: MessageV2.WithParts[] }) {
+  async function summarizeSession(input: { sessionID: SessionID; messages: MessageV2.WithParts[] }) {
    const diffs = await computeDiff({ messages: input.messages })
    await Session.setSummary({
      sessionID: input.sessionID,
@@ -113,7 +114,7 @@ export namespace SessionSummary {

  export const diff = fn(
    z.object({
-      sessionID: Identifier.schema("session"),
+      sessionID: SessionID.zod,
      messageID: Identifier.schema("message").optional(),
    }),
    async (input) => {
--- a/packages/opencode/src/session/todo.ts
+++ b/packages/opencode/src/session/todo.ts
@@ -1,5 +1,6 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
+import { SessionID } from "./schema"
 import z from "zod"
 import { Database, eq, asc } from "../storage/db"
 import { TodoTable } from "./session.sql"
@@ -18,13 +19,13 @@ export namespace Todo {
    Updated: BusEvent.define(
      "todo.updated",
      z.object({
-        sessionID: z.string(),
+        sessionID: SessionID.zod,
        todos: z.array(Info),
      }),
    ),
  }

-  export function update(input: { sessionID: string; todos: Info[] }) {
+  export function update(input: { sessionID: SessionID; todos: Info[] }) {
    Database.transaction((db) => {
      db.delete(TodoTable).where(eq(TodoTable.session_id, input.sessionID)).run()
      if (input.todos.length === 0) return
@@ -43,7 +44,7 @@ export namespace Todo {
    Bus.publish(Event.Updated, input)
  }

-  export function get(sessionID: string) {
+  export function get(sessionID: SessionID) {
    const rows = Database.use((db) =>
      db.select().from(TodoTable).where(eq(TodoTable.session_id, sessionID)).orderBy(asc(TodoTable.position)).all(),
    )
--- a/packages/opencode/src/share/share-next.ts
+++ b/packages/opencode/src/share/share-next.ts
@@ -3,6 +3,7 @@ import { Account } from "@/account"
 import { Config } from "@/config/config"
 import { Provider } from "@/provider/provider"
 import { Session } from "@/session"
+import type { SessionID } from "@/session/schema"
 import { MessageV2 } from "@/session/message-v2"
 import { Database, eq } from "@/storage/db"
 import { SessionShareTable } from "./share.sql"
@@ -109,7 +110,7 @@ export namespace ShareNext {
    })
  }

-  export async function create(sessionID: string) {
+  export async function create(sessionID: SessionID) {
    if (disabled) return { id: "", url: "", secret: "" }
    log.info("creating share", { sessionID })
    const req = await request()
@@ -140,7 +141,7 @@ export namespace ShareNext {
    return result
  }

-  function get(sessionID: string) {
+  function get(sessionID: SessionID) {
    const row = Database.use((db) =>
      db.select().from(SessionShareTable).where(eq(SessionShareTable.session_id, sessionID)).get(),
    )
@@ -186,7 +187,7 @@ export namespace ShareNext {
  }

  const queue = new Map<string, { timeout: NodeJS.Timeout; data: Map<string, Data> }>()
-  async function sync(sessionID: string, data: Data[]) {
+  async function sync(sessionID: SessionID, data: Data[]) {
    if (disabled) return
    const existing = queue.get(sessionID)
    if (existing) {
@@ -225,7 +226,7 @@ export namespace ShareNext {
    queue.set(sessionID, { timeout, data: dataMap })
  }

-  export async function remove(sessionID: string) {
+  export async function remove(sessionID: SessionID) {
    if (disabled) return
    log.info("removing share", { sessionID })
    const share = get(sessionID)
@@ -248,7 +249,7 @@ export namespace ShareNext {
    Database.use((db) => db.delete(SessionShareTable).where(eq(SessionShareTable.session_id, sessionID)).run())
  }

-  async function fullSync(sessionID: string) {
+  async function fullSync(sessionID: SessionID) {
    log.info("full sync", { sessionID })
    const session = await Session.get(sessionID)
    const diffs = await Session.diff(sessionID)
--- a/packages/opencode/src/tool/plan.ts
+++ b/packages/opencode/src/tool/plan.ts
@@ -7,9 +7,10 @@ import { MessageV2 } from "../session/message-v2"
 import { Identifier } from "../id/id"
 import { Provider } from "../provider/provider"
 import { Instance } from "../project/instance"
+import type { SessionID } from "../session/schema"
 import EXIT_DESCRIPTION from "./plan-exit.txt"

-async function getLastModel(sessionID: string) {
+async function getLastModel(sessionID: SessionID) {
  for await (const item of MessageV2.stream(sessionID)) {
    if (item.info.role === "user" && item.info.model) return item.info.model
  }
--- a/packages/opencode/src/tool/task.ts
+++ b/packages/opencode/src/tool/task.ts
@@ -2,6 +2,7 @@ import { Tool } from "./tool"
 import DESCRIPTION from "./task.txt"
 import z from "zod"
 import { Session } from "../session"
+import { SessionID } from "../session/schema"
 import { MessageV2 } from "../session/message-v2"
 import { Identifier } from "../id/id"
 import { Agent } from "../agent/agent"
@@ -65,7 +66,7 @@ export const TaskTool = Tool.define("task", async (ctx) => {

      const session = await iife(async () => {
        if (params.task_id) {
-          const found = await Session.get(params.task_id).catch(() => {})
+          const found = await Session.get(SessionID.make(params.task_id)).catch(() => {})
          if (found) return found
        }

--- a/packages/opencode/src/tool/tool.ts
+++ b/packages/opencode/src/tool/tool.ts
@@ -2,6 +2,7 @@ import z from "zod"
 import type { MessageV2 } from "../session/message-v2"
 import type { Agent } from "../agent/agent"
 import type { PermissionNext } from "../permission/next"
+import type { SessionID } from "../session/schema"
 import { Truncate } from "./truncation"

 export namespace Tool {
@@ -14,7 +15,7 @@ export namespace Tool {
  }

  export type Context<M extends Metadata = Metadata> = {
-    sessionID: string
+    sessionID: SessionID
    messageID: string
    agent: string
    abort: AbortSignal