Upgrade to Zod v4 (#2605)

Co-authored-by: GitHub Action <action@github.com>

packages/opencode/package.json

@@ -28,6 +28,7 @@
   },
   "dependencies": {
     "@clack/prompts": "1.0.0-alpha.1",
+    "@hono/standard-validator": "0.1.5",
     "@hono/zod-validator": "catalog:",
     "@modelcontextprotocol/sdk": "1.15.1",
     "@openauthjs/openauth": "0.4.3",
@@ -40,7 +41,7 @@
     "diff": "8.0.2",
     "gray-matter": "4.0.3",
     "hono": "catalog:",
-    "hono-openapi": "0.4.8",
+    "hono-openapi": "1.0.7",
     "ignore": "7.0.5",
     "jsonc-parser": "3.3.1",
     "minimatch": "10.0.3",
@@ -54,7 +55,6 @@
     "web-tree-sitter": "0.22.6",
     "xdg-basedir": "5.1.0",
     "yargs": "18.0.0",
-    "zod": "catalog:",
-    "zod-openapi": "4.1.0"
+    "zod": "catalog:"
   }
 }

packages/opencode/script/schema.ts

@@ -1,13 +1,12 @@
 #!/usr/bin/env bun
 
-import "zod-openapi/extend"
+import { z } from "zod/v4"
 import { Config } from "../src/config/config"
-import { zodToJsonSchema } from "zod-to-json-schema"
 
 const file = process.argv[2]
 console.log(file)
 
-const result = zodToJsonSchema(Config.Info, {
+const result = z.toJSONSchema(Config.Info, {
   /**
    * We'll use the `default` values of the field as the only value in `examples`.
    * This will ensure no docs are needed to be read, as the configuration is
@@ -15,10 +14,8 @@ const result = zodToJsonSchema(Config.Info, {
    *
    * See https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.9.5
    */
-  postProcess(jsonSchema) {
-    const schema = jsonSchema as typeof jsonSchema & {
-      examples?: unknown[]
-    }
+  override(input) {
+    const schema = input.jsonSchema
     if (schema && typeof schema === "object" && "type" in schema && schema.type === "string" && schema?.default) {
       if (!schema.examples) {
         schema.examples = [schema.default]
@@ -29,8 +26,6 @@ const result = zodToJsonSchema(Config.Info, {
         .join("\n\n")
         .trim()
     }
-
-    return jsonSchema
   },
 }) as Record<string, unknown> & {
   allowComments?: boolean

packages/opencode/src/agent/agent.ts

@@ -1,5 +1,5 @@
 import { Config } from "../config/config"
-import z from "zod"
+import z from "zod/v4"
 import { Provider } from "../provider/provider"
 import { generateObject, type ModelMessage } from "ai"
 import PROMPT_GENERATE from "./generate.txt"
@@ -28,10 +28,10 @@ export namespace Agent {
         })
         .optional(),
       prompt: z.string().optional(),
-      tools: z.record(z.boolean()),
+      tools: z.record(z.string(), z.boolean()),
       options: z.record(z.string(), z.any()),
     })
-    .openapi({
+    .meta({
       ref: "Agent",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/auth/github-copilot.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Auth } from "./index"
 import { NamedError } from "../util/error"
 

packages/opencode/src/auth/index.ts

@@ -1,7 +1,7 @@
 import path from "path"
 import { Global } from "../global"
 import fs from "fs/promises"
-import { z } from "zod"
+import z from "zod/v4"
 
 export namespace Auth {
   export const Oauth = z
@@ -11,14 +11,14 @@ export namespace Auth {
       access: z.string(),
       expires: z.number(),
     })
-    .openapi({ ref: "OAuth" })
+    .meta({ ref: "OAuth" })
 
   export const Api = z
     .object({
       type: z.literal("api"),
       key: z.string(),
     })
-    .openapi({ ref: "ApiAuth" })
+    .meta({ ref: "ApiAuth" })
 
   export const WellKnown = z
     .object({
@@ -26,9 +26,9 @@ export namespace Auth {
       key: z.string(),
       token: z.string(),
     })
-    .openapi({ ref: "WellKnownAuth" })
+    .meta({ ref: "WellKnownAuth" })
 
-  export const Info = z.discriminatedUnion("type", [Oauth, Api, WellKnown]).openapi({ ref: "Auth" })
+  export const Info = z.discriminatedUnion("type", [Oauth, Api, WellKnown]).meta({ ref: "Auth" })
   export type Info = z.infer<typeof Info>
 
   const filepath = path.join(Global.Path.data, "auth.json")

packages/opencode/src/bun/index.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Global } from "../global"
 import { Log } from "../util/log"
 import path from "path"

packages/opencode/src/bus/index.ts

@@ -1,4 +1,5 @@
-import { z, type ZodType } from "zod"
+import z from "zod/v4"
+import type { ZodType } from "zod/v4"
 import { Log } from "../util/log"
 import { Instance } from "../project/instance"
 
@@ -38,7 +39,7 @@ export namespace Bus {
               type: z.literal(type),
               properties: def.properties,
             })
-            .openapi({
+            .meta({
               ref: "Event" + "." + def.type,
             }),
         )

packages/opencode/src/cli/ui.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { EOL } from "os"
 import { NamedError } from "../util/error"
 

packages/opencode/src/command/index.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { Config } from "../config/config"
 import { Instance } from "../project/instance"
 
@@ -12,7 +12,7 @@ export namespace Command {
       template: z.string(),
       subtask: z.boolean().optional(),
     })
-    .openapi({
+    .meta({
       ref: "Command",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/config/config.ts

@@ -1,7 +1,7 @@
 import { Log } from "../util/log"
 import path from "path"
 import os from "os"
-import { z } from "zod"
+import z from "zod/v4"
 import { Filesystem } from "../util/filesystem"
 import { ModelsDev } from "../provider/models"
 import { mergeDeep, pipe } from "remeda"
@@ -217,7 +217,7 @@ export namespace Config {
       enabled: z.boolean().optional().describe("Enable or disable the MCP server on startup"),
     })
     .strict()
-    .openapi({
+    .meta({
       ref: "McpLocalConfig",
     })
 
@@ -229,7 +229,7 @@ export namespace Config {
       headers: z.record(z.string(), z.string()).optional().describe("Headers to send with the request"),
     })
     .strict()
-    .openapi({
+    .meta({
       ref: "McpRemoteConfig",
     })
 
@@ -267,7 +267,7 @@ export namespace Config {
         .optional(),
     })
     .catchall(z.any())
-    .openapi({
+    .meta({
       ref: "AgentConfig",
     })
   export type Agent = z.infer<typeof Agent>
@@ -342,7 +342,7 @@ export namespace Config {
       messages_revert: z.string().optional().default("none").describe("@deprecated use messages_undo. Revert message"),
     })
     .strict()
-    .openapi({
+    .meta({
       ref: "KeybindsConfig",
     })
 
@@ -350,7 +350,7 @@ export namespace Config {
     scroll_speed: z.number().min(1).optional().default(2).describe("TUI scroll speed"),
   })
 
-  export const Layout = z.enum(["auto", "stretch"]).openapi({
+  export const Layout = z.enum(["auto", "stretch"]).meta({
     ref: "LayoutConfig",
   })
   export type Layout = z.infer<typeof Layout>
@@ -407,9 +407,10 @@ export namespace Config {
         .describe("Agent configuration, see https://opencode.ai/docs/agent"),
       provider: z
         .record(
+          z.string(),
           ModelsDev.Provider.partial()
             .extend({
-              models: z.record(ModelsDev.Model.partial()).optional(),
+              models: z.record(z.string(), ModelsDev.Model.partial()).optional(),
               options: z
                 .object({
                   apiKey: z.string().optional(),
@@ -505,7 +506,7 @@ export namespace Config {
         .optional(),
     })
     .strict()
-    .openapi({
+    .meta({
       ref: "Config",
     })
 
@@ -644,7 +645,7 @@ export namespace Config {
     "ConfigInvalidError",
     z.object({
       path: z.string(),
-      issues: z.custom<z.ZodIssue[]>().optional(),
+      issues: z.custom<z.core.$ZodIssue[]>().optional(),
       message: z.string().optional(),
     }),
   )

packages/opencode/src/file/fzf.ts

@@ -1,7 +1,7 @@
 import path from "path"
 import { Global } from "../global"
 import fs from "fs/promises"
-import { z } from "zod"
+import z from "zod/v4"
 import { NamedError } from "../util/error"
 import { lazy } from "../util/lazy"
 import { Log } from "../util/log"

packages/opencode/src/file/index.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Bus } from "../bus"
 import { $ } from "bun"
 import { formatPatch, structuredPatch } from "diff"
@@ -18,7 +18,7 @@ export namespace File {
       removed: z.number().int(),
       status: z.enum(["added", "deleted", "modified"]),
     })
-    .openapi({
+    .meta({
       ref: "File",
     })
 
@@ -32,7 +32,7 @@ export namespace File {
       type: z.enum(["file", "directory"]),
       ignored: z.boolean(),
     })
-    .openapi({
+    .meta({
       ref: "FileNode",
     })
   export type Node = z.infer<typeof Node>
@@ -60,7 +60,7 @@ export namespace File {
         })
         .optional(),
     })
-    .openapi({
+    .meta({
       ref: "FileContent",
     })
   export type Content = z.infer<typeof Content>

packages/opencode/src/file/ripgrep.ts

@@ -2,7 +2,7 @@
 import path from "path"
 import { Global } from "../global"
 import fs from "fs/promises"
-import { z } from "zod"
+import z from "zod/v4"
 import { NamedError } from "../util/error"
 import { lazy } from "../util/lazy"
 import { $ } from "bun"

packages/opencode/src/file/watch.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Bus } from "../bus"
 import fs from "fs"
 import { Log } from "../util/log"

packages/opencode/src/id/id.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { randomBytes } from "crypto"
 
 export namespace Identifier {

packages/opencode/src/ide/index.ts

@@ -1,5 +1,5 @@
 import { spawn } from "bun"
-import { z } from "zod"
+import z from "zod/v4"
 import { NamedError } from "../util/error"
 import { Log } from "../util/log"
 import { Bus } from "../bus"

packages/opencode/src/index.ts

@@ -1,4 +1,3 @@
-import "zod-openapi/extend"
 import yargs from "yargs"
 import { hideBin } from "yargs/helpers"
 import { RunCommand } from "./cli/cmd/run"

packages/opencode/src/installation/index.ts

@@ -1,6 +1,6 @@
 import path from "path"
 import { $ } from "bun"
-import { z } from "zod"
+import z from "zod/v4"
 import { NamedError } from "../util/error"
 import { Bus } from "../bus"
 import { Log } from "../util/log"
@@ -28,7 +28,7 @@ export namespace Installation {
       version: z.string(),
       latest: z.string(),
     })
-    .openapi({
+    .meta({
       ref: "InstallationInfo",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/lsp/client.ts

@@ -4,7 +4,7 @@ import type { Diagnostic as VSCodeDiagnostic } from "vscode-languageserver-types
 import { Log } from "../util/log"
 import { LANGUAGE_EXTENSIONS } from "./language"
 import { Bus } from "../bus"
-import z from "zod"
+import z from "zod/v4"
 import type { LSPServer } from "./server"
 import { NamedError } from "../util/error"
 import { withTimeout } from "../util/timeout"

packages/opencode/src/lsp/index.ts

@@ -2,7 +2,7 @@ import { Log } from "../util/log"
 import { LSPClient } from "./client"
 import path from "path"
 import { LSPServer } from "./server"
-import { z } from "zod"
+import z from "zod/v4"
 import { Config } from "../config/config"
 import { spawn } from "child_process"
 import { Instance } from "../project/instance"
@@ -21,7 +21,7 @@ export namespace LSP {
         character: z.number(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "Range",
     })
   export type Range = z.infer<typeof Range>
@@ -35,7 +35,7 @@ export namespace LSP {
         range: Range,
       }),
     })
-    .openapi({
+    .meta({
       ref: "Symbol",
     })
   export type Symbol = z.infer<typeof Symbol>
@@ -48,7 +48,7 @@ export namespace LSP {
       range: Range,
       selectionRange: Range,
     })
-    .openapi({
+    .meta({
       ref: "DocumentSymbol",
     })
   export type DocumentSymbol = z.infer<typeof DocumentSymbol>

packages/opencode/src/mcp/index.ts

@@ -5,7 +5,7 @@ import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js"
 import { Config } from "../config/config"
 import { Log } from "../util/log"
 import { NamedError } from "../util/error"
-import { z } from "zod"
+import z from "zod/v4"
 import { Session } from "../session"
 import { Bus } from "../bus"
 import { Instance } from "../project/instance"

packages/opencode/src/permission/index.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Bus } from "../bus"
 import { Log } from "../util/log"
 import { Identifier } from "../id/id"
@@ -27,12 +27,12 @@ export namespace Permission {
       messageID: z.string(),
       callID: z.string().optional(),
       title: z.string(),
-      metadata: z.record(z.any()),
+      metadata: z.record(z.string(), z.any()),
       time: z.object({
         created: z.number(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "Permission",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/project/project.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { Filesystem } from "../util/filesystem"
 import path from "path"
 import { $ } from "bun"
@@ -17,7 +17,7 @@ export namespace Project {
         initialized: z.number().optional(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "Project",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/provider/models.ts

@@ -1,7 +1,7 @@
 import { Global } from "../global"
 import { Log } from "../util/log"
 import path from "path"
-import { z } from "zod"
+import z from "zod/v4"
 import { data } from "./models-macro" with { type: "macro" }
 import { Installation } from "../installation"
 
@@ -29,10 +29,10 @@ export namespace ModelsDev {
         output: z.number(),
       }),
       experimental: z.boolean().optional(),
-      options: z.record(z.any()),
+      options: z.record(z.string(), z.any()),
       provider: z.object({ npm: z.string() }).optional(),
     })
-    .openapi({
+    .meta({
       ref: "Model",
     })
   export type Model = z.infer<typeof Model>
@@ -44,9 +44,9 @@ export namespace ModelsDev {
       env: z.array(z.string()),
       id: z.string(),
       npm: z.string().optional(),
-      models: z.record(Model),
+      models: z.record(z.string(), Model),
     })
-    .openapi({
+    .meta({
       ref: "Provider",
     })
 

packages/opencode/src/provider/provider.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import path from "path"
 import { Config } from "../config/config"
 import { mergeDeep, sortBy } from "remeda"

packages/opencode/src/provider/transform.ts

@@ -1,5 +1,6 @@
 import type { ModelMessage } from "ai"
 import { unique } from "remeda"
+import type { JSONSchema } from "zod/v4/core"
 
 export namespace ProviderTransform {
   function normalizeToolCallIds(msgs: ModelMessage[]): ModelMessage[] {
@@ -112,4 +113,29 @@ export namespace ProviderTransform {
     }
     return outputLimit
   }
+
+  export function schema(_providerID: string, _modelID: string, schema: JSONSchema.BaseSchema) {
+    /*
+    if (["openai", "azure"].includes(providerID)) {
+      if (schema.type === "object" && schema.properties) {
+        for (const [key, value] of Object.entries(schema.properties)) {
+          if (schema.required?.includes(key)) continue
+          schema.properties[key] = {
+            anyOf: [
+              value as JSONSchema.JSONSchema,
+              {
+                type: "null",
+              },
+            ],
+          }
+        }
+      }
+    }
+
+    if (providerID === "google") {
+    }
+    */
+
+    return schema
+  }
 }

packages/opencode/src/server/project.ts

@@ -1,6 +1,6 @@
 import { Hono } from "hono"
 import { describeRoute } from "hono-openapi"
-import { resolver } from "hono-openapi/zod"
+import { resolver } from "hono-openapi"
 import { Instance } from "../project/instance"
 import { Project } from "../project/project"
 

packages/opencode/src/server/server.ts

@@ -1,11 +1,10 @@
 import { Log } from "../util/log"
 import { Bus } from "../bus"
-import { describeRoute, generateSpecs, openAPISpecs } from "hono-openapi"
+import { describeRoute, generateSpecs, validator, resolver, openAPIRouteHandler } from "hono-openapi"
 import { Hono } from "hono"
 import { streamSSE } from "hono/streaming"
 import { Session } from "../session"
-import { resolver, validator as zValidator } from "hono-openapi/zod"
-import { z } from "zod"
+import z from "zod/v4"
 import { Provider } from "../provider/provider"
 import { mapValues } from "remeda"
 import { NamedError } from "../util/error"
@@ -39,7 +38,7 @@ const ERRORS = {
             .object({
               data: z.record(z.string(), z.any()),
             })
-            .openapi({
+            .meta({
               ref: "Error",
             }),
         ),
@@ -59,7 +58,7 @@ export namespace Server {
       optional: z.boolean().optional(),
       items: z.enum(["string", "number", "boolean"]).optional(),
     })
-    .openapi({ ref: "HttpParamSpec" })
+    .meta({ ref: "HttpParamSpec" })
 
   const HttpToolRegistration = z
     .object({
@@ -67,12 +66,12 @@ export namespace Server {
       description: z.string(),
       parameters: z.object({
         type: z.literal("object"),
-        properties: z.record(HttpParamSpec),
+        properties: z.record(z.string(), HttpParamSpec),
       }),
       callbackUrl: z.string(),
       headers: z.record(z.string(), z.string()).optional(),
     })
-    .openapi({ ref: "HttpToolRegistration" })
+    .meta({ ref: "HttpToolRegistration" })
 
   export const Event = {
     Connected: Bus.event("server.connected", z.object({})),
@@ -115,10 +114,9 @@ export namespace Server {
         return next()
       })
     })
-    .use(zValidator("query", z.object({ directory: z.string().optional() })))
     .get(
       "/doc",
-      openAPISpecs(app, {
+      openAPIRouteHandler(app, {
         documentation: {
           info: {
             title: "opencode",
@@ -129,6 +127,7 @@ export namespace Server {
         },
       }),
     )
+    .use(validator("query", z.object({ directory: z.string().optional() })))
     .route("/project", ProjectRoute)
     .get(
       "/event",
@@ -141,7 +140,7 @@ export namespace Server {
             content: {
               "text/event-stream": {
                 schema: resolver(
-                  Bus.payloads().openapi({
+                  Bus.payloads().meta({
                     ref: "Event",
                   }),
                 ),
@@ -211,7 +210,7 @@ export namespace Server {
           ...ERRORS,
         },
       }),
-      zValidator("json", HttpToolRegistration),
+      validator("json", HttpToolRegistration),
       async (c) => {
         ToolRegistry.registerHTTP(c.req.valid("json"))
         return c.json(true)
@@ -227,7 +226,7 @@ export namespace Server {
             description: "Tool IDs",
             content: {
               "application/json": {
-                schema: resolver(z.array(z.string()).openapi({ ref: "ToolIDs" })),
+                schema: resolver(z.array(z.string()).meta({ ref: "ToolIDs" })),
               },
             },
           },
@@ -257,9 +256,9 @@ export namespace Server {
                           description: z.string(),
                           parameters: z.any(),
                         })
-                        .openapi({ ref: "ToolListItem" }),
+                        .meta({ ref: "ToolListItem" }),
                     )
-                    .openapi({ ref: "ToolList" }),
+                    .meta({ ref: "ToolList" }),
                 ),
               },
             },
@@ -267,7 +266,7 @@ export namespace Server {
           ...ERRORS,
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           provider: z.string(),
@@ -305,7 +304,7 @@ export namespace Server {
                       worktree: z.string(),
                       directory: z.string(),
                     })
-                    .openapi({
+                    .meta({
                       ref: "Path",
                     }),
                 ),
@@ -361,7 +360,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -389,7 +388,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -418,7 +417,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "json",
         z
           .object({
@@ -449,7 +448,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -476,13 +475,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
         }),
       ),
-      zValidator(
+      validator(
         "json",
         z.object({
           title: z.string().optional(),
@@ -517,13 +516,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
-      zValidator(
+      validator(
         "json",
         z.object({
           messageID: z.string(),
@@ -554,7 +553,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -580,7 +579,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -609,7 +608,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -638,13 +637,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
-      zValidator(
+      validator(
         "json",
         z.object({
           providerID: z.string(),
@@ -674,10 +673,10 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
       async (c) => {
@@ -706,11 +705,11 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
-          messageID: z.string().openapi({ description: "Message ID" }),
+          id: z.string().meta({ description: "Session ID" }),
+          messageID: z.string().meta({ description: "Message ID" }),
         }),
       ),
       async (c) => {
@@ -740,13 +739,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
-      zValidator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
+      validator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
       async (c) => {
         const sessionID = c.req.valid("param").id
         const body = c.req.valid("json")
@@ -775,13 +774,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
-      zValidator("json", SessionPrompt.CommandInput.omit({ sessionID: true })),
+      validator("json", SessionPrompt.CommandInput.omit({ sessionID: true })),
       async (c) => {
         const sessionID = c.req.valid("param").id
         const body = c.req.valid("json")
@@ -805,13 +804,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
-          id: z.string().openapi({ description: "Session ID" }),
+          id: z.string().meta({ description: "Session ID" }),
         }),
       ),
-      zValidator("json", SessionPrompt.ShellInput.omit({ sessionID: true })),
+      validator("json", SessionPrompt.ShellInput.omit({ sessionID: true })),
       async (c) => {
         const sessionID = c.req.valid("param").id
         const body = c.req.valid("json")
@@ -835,13 +834,13 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
         }),
       ),
-      zValidator("json", SessionRevert.RevertInput.omit({ sessionID: true })),
+      validator("json", SessionRevert.RevertInput.omit({ sessionID: true })),
       async (c) => {
         const id = c.req.valid("param").id
         log.info("revert", c.req.valid("json"))
@@ -865,7 +864,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
@@ -892,14 +891,14 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
           permissionID: z.string(),
         }),
       ),
-      zValidator("json", z.object({ response: Permission.Response })),
+      validator("json", z.object({ response: Permission.Response })),
       async (c) => {
         const params = c.req.valid("param")
         const id = params.id
@@ -974,7 +973,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           pattern: z.string(),
@@ -1006,7 +1005,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           query: z.string(),
@@ -1038,7 +1037,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           query: z.string(),
@@ -1066,7 +1065,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           path: z.string(),
@@ -1094,7 +1093,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "query",
         z.object({
           path: z.string(),
@@ -1143,16 +1142,16 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "json",
         z.object({
-          service: z.string().openapi({ description: "Service name for the log entry" }),
-          level: z.enum(["debug", "info", "error", "warn"]).openapi({ description: "Log level" }),
-          message: z.string().openapi({ description: "Log message" }),
+          service: z.string().meta({ description: "Service name for the log entry" }),
+          level: z.enum(["debug", "info", "error", "warn"]).meta({ description: "Log level" }),
+          message: z.string().meta({ description: "Log message" }),
           extra: z
             .record(z.string(), z.any())
             .optional()
-            .openapi({ description: "Additional metadata for the log entry" }),
+            .meta({ description: "Additional metadata for the log entry" }),
         }),
       ),
       async (c) => {
@@ -1214,7 +1213,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "json",
         z.object({
           text: z.string(),
@@ -1346,7 +1345,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "json",
         z.object({
           command: z.string(),
@@ -1370,7 +1369,7 @@ export namespace Server {
           },
         },
       }),
-      zValidator(
+      validator(
         "json",
         z.object({
           title: z.string().optional(),
@@ -1398,13 +1397,13 @@ export namespace Server {
           ...ERRORS,
         },
       }),
-      zValidator(
+      validator(
         "param",
         z.object({
           id: z.string(),
         }),
       ),
-      zValidator("json", Auth.Info),
+      validator("json", Auth.Info),
       async (c) => {
         const id = c.req.valid("param").id
         const info = c.req.valid("json")

packages/opencode/src/session/compaction.ts

@@ -7,7 +7,7 @@ import { defer } from "../util/defer"
 import { MessageV2 } from "./message-v2"
 import { SystemPrompt } from "./system"
 import { Bus } from "../bus"
-import z from "zod"
+import z from "zod/v4"
 import type { ModelsDev } from "../provider/models"
 import { SessionPrompt } from "./prompt"
 import { Flag } from "../flag/flag"

packages/opencode/src/session/index.ts

@@ -1,5 +1,5 @@
 import { Decimal } from "decimal.js"
-import { z } from "zod"
+import z from "zod/v4"
 import { type LanguageModelUsage, type ProviderMetadata } from "ai"
 
 import PROMPT_INITIALIZE from "../session/prompt/initialize.txt"
@@ -56,7 +56,7 @@ export namespace Session {
         })
         .optional(),
     })
-    .openapi({
+    .meta({
       ref: "Session",
     })
   export type Info = z.output<typeof Info>
@@ -66,7 +66,7 @@ export namespace Session {
       secret: z.string(),
       url: z.string(),
     })
-    .openapi({
+    .meta({
       ref: "SessionShare",
     })
   export type ShareInfo = z.output<typeof ShareInfo>

packages/opencode/src/session/message-v2.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { Bus } from "../bus"
 import { NamedError } from "../util/error"
 import { Message } from "./message"
@@ -8,7 +8,7 @@ import { LSP } from "../lsp"
 
 export namespace MessageV2 {
   export const OutputLengthError = NamedError.create("MessageOutputLengthError", z.object({}))
-  export const AbortedError = NamedError.create("MessageAbortedError", z.object({}))
+  export const AbortedError = NamedError.create("MessageAbortedError", z.object({ message: z.string() }))
   export const AuthError = NamedError.create(
     "ProviderAuthError",
     z.object({
@@ -21,7 +21,7 @@ export namespace MessageV2 {
     .object({
       status: z.literal("pending"),
     })
-    .openapi({
+    .meta({
       ref: "ToolStatePending",
     })
 
@@ -32,12 +32,12 @@ export namespace MessageV2 {
       status: z.literal("running"),
       input: z.any(),
       title: z.string().optional(),
-      metadata: z.record(z.any()).optional(),
+      metadata: z.record(z.string(), z.any()).optional(),
       time: z.object({
         start: z.number(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "ToolStateRunning",
     })
   export type ToolStateRunning = z.infer<typeof ToolStateRunning>
@@ -45,17 +45,17 @@ export namespace MessageV2 {
   export const ToolStateCompleted = z
     .object({
       status: z.literal("completed"),
-      input: z.record(z.any()),
+      input: z.record(z.string(), z.any()),
       output: z.string(),
       title: z.string(),
-      metadata: z.record(z.any()),
+      metadata: z.record(z.string(), z.any()),
       time: z.object({
         start: z.number(),
         end: z.number(),
         compacted: z.number().optional(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "ToolStateCompleted",
     })
   export type ToolStateCompleted = z.infer<typeof ToolStateCompleted>
@@ -63,22 +63,22 @@ export namespace MessageV2 {
   export const ToolStateError = z
     .object({
       status: z.literal("error"),
-      input: z.record(z.any()),
+      input: z.record(z.string(), z.any()),
       error: z.string(),
-      metadata: z.record(z.any()).optional(),
+      metadata: z.record(z.string(), z.any()).optional(),
       time: z.object({
         start: z.number(),
         end: z.number(),
       }),
     })
-    .openapi({
+    .meta({
       ref: "ToolStateError",
     })
   export type ToolStateError = z.infer<typeof ToolStateError>
 
   export const ToolState = z
     .discriminatedUnion("status", [ToolStatePending, ToolStateRunning, ToolStateCompleted, ToolStateError])
-    .openapi({
+    .meta({
       ref: "ToolState",
     })
 
@@ -91,7 +91,7 @@ export namespace MessageV2 {
   export const SnapshotPart = PartBase.extend({
     type: z.literal("snapshot"),
     snapshot: z.string(),
-  }).openapi({
+  }).meta({
     ref: "SnapshotPart",
   })
   export type SnapshotPart = z.infer<typeof SnapshotPart>
@@ -100,7 +100,7 @@ export namespace MessageV2 {
     type: z.literal("patch"),
     hash: z.string(),
     files: z.string().array(),
-  }).openapi({
+  }).meta({
     ref: "PatchPart",
   })
   export type PatchPart = z.infer<typeof PatchPart>
@@ -115,7 +115,7 @@ export namespace MessageV2 {
         end: z.number().optional(),
       })
       .optional(),
-  }).openapi({
+  }).meta({
     ref: "TextPart",
   })
   export type TextPart = z.infer<typeof TextPart>
@@ -123,12 +123,12 @@ export namespace MessageV2 {
   export const ReasoningPart = PartBase.extend({
     type: z.literal("reasoning"),
     text: z.string(),
-    metadata: z.record(z.any()).optional(),
+    metadata: z.record(z.string(), z.any()).optional(),
     time: z.object({
       start: z.number(),
       end: z.number().optional(),
     }),
-  }).openapi({
+  }).meta({
     ref: "ReasoningPart",
   })
   export type ReasoningPart = z.infer<typeof ReasoningPart>
@@ -138,7 +138,7 @@ export namespace MessageV2 {
     callID: z.string(),
     tool: z.string(),
     state: ToolState,
-  }).openapi({
+  }).meta({
     ref: "ToolPart",
   })
   export type ToolPart = z.infer<typeof ToolPart>
@@ -150,7 +150,7 @@ export namespace MessageV2 {
         start: z.number().int(),
         end: z.number().int(),
       })
-      .openapi({
+      .meta({
         ref: "FilePartSourceText",
       }),
   })
@@ -158,7 +158,7 @@ export namespace MessageV2 {
   export const FileSource = FilePartSourceBase.extend({
     type: z.literal("file"),
     path: z.string(),
-  }).openapi({
+  }).meta({
     ref: "FileSource",
   })
 
@@ -168,11 +168,11 @@ export namespace MessageV2 {
     range: LSP.Range,
     name: z.string(),
     kind: z.number().int(),
-  }).openapi({
+  }).meta({
     ref: "SymbolSource",
   })
 
-  export const FilePartSource = z.discriminatedUnion("type", [FileSource, SymbolSource]).openapi({
+  export const FilePartSource = z.discriminatedUnion("type", [FileSource, SymbolSource]).meta({
     ref: "FilePartSource",
   })
 
@@ -182,7 +182,7 @@ export namespace MessageV2 {
     filename: z.string().optional(),
     url: z.string(),
     source: FilePartSource.optional(),
-  }).openapi({
+  }).meta({
     ref: "FilePart",
   })
   export type FilePart = z.infer<typeof FilePart>
@@ -197,14 +197,14 @@ export namespace MessageV2 {
         end: z.number().int(),
       })
       .optional(),
-  }).openapi({
+  }).meta({
     ref: "AgentPart",
   })
   export type AgentPart = z.infer<typeof AgentPart>
 
   export const StepStartPart = PartBase.extend({
     type: z.literal("step-start"),
-  }).openapi({
+  }).meta({
     ref: "StepStartPart",
   })
   export type StepStartPart = z.infer<typeof StepStartPart>
@@ -221,7 +221,7 @@ export namespace MessageV2 {
         write: z.number(),
       }),
     }),
-  }).openapi({
+  }).meta({
     ref: "StepFinishPart",
   })
   export type StepFinishPart = z.infer<typeof StepFinishPart>
@@ -236,7 +236,7 @@ export namespace MessageV2 {
     time: z.object({
       created: z.number(),
     }),
-  }).openapi({
+  }).meta({
     ref: "UserMessage",
   })
   export type User = z.infer<typeof User>
@@ -253,7 +253,7 @@ export namespace MessageV2 {
       PatchPart,
       AgentPart,
     ])
-    .openapi({
+    .meta({
       ref: "Part",
     })
   export type Part = z.infer<typeof Part>
@@ -291,12 +291,12 @@ export namespace MessageV2 {
         write: z.number(),
       }),
     }),
-  }).openapi({
+  }).meta({
     ref: "AssistantMessage",
   })
   export type Assistant = z.infer<typeof Assistant>
 
-  export const Info = z.discriminatedUnion("role", [User, Assistant]).openapi({
+  export const Info = z.discriminatedUnion("role", [User, Assistant]).meta({
     ref: "Message",
   })
   export type Info = z.infer<typeof Info>

packages/opencode/src/session/message.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { NamedError } from "../util/error"
 
 export namespace Message {
@@ -19,7 +19,7 @@ export namespace Message {
       toolName: z.string(),
       args: z.custom<Required<unknown>>(),
     })
-    .openapi({
+    .meta({
       ref: "ToolCall",
     })
   export type ToolCall = z.infer<typeof ToolCall>
@@ -32,7 +32,7 @@ export namespace Message {
       toolName: z.string(),
       args: z.custom<Required<unknown>>(),
     })
-    .openapi({
+    .meta({
       ref: "ToolPartialCall",
     })
   export type ToolPartialCall = z.infer<typeof ToolPartialCall>
@@ -46,12 +46,12 @@ export namespace Message {
       args: z.custom<Required<unknown>>(),
       result: z.string(),
     })
-    .openapi({
+    .meta({
       ref: "ToolResult",
     })
   export type ToolResult = z.infer<typeof ToolResult>
 
-  export const ToolInvocation = z.discriminatedUnion("state", [ToolCall, ToolPartialCall, ToolResult]).openapi({
+  export const ToolInvocation = z.discriminatedUnion("state", [ToolCall, ToolPartialCall, ToolResult]).meta({
     ref: "ToolInvocation",
   })
   export type ToolInvocation = z.infer<typeof ToolInvocation>
@@ -61,7 +61,7 @@ export namespace Message {
       type: z.literal("text"),
       text: z.string(),
     })
-    .openapi({
+    .meta({
       ref: "TextPart",
     })
   export type TextPart = z.infer<typeof TextPart>
@@ -70,9 +70,9 @@ export namespace Message {
     .object({
       type: z.literal("reasoning"),
       text: z.string(),
-      providerMetadata: z.record(z.any()).optional(),
+      providerMetadata: z.record(z.string(), z.any()).optional(),
     })
-    .openapi({
+    .meta({
       ref: "ReasoningPart",
     })
   export type ReasoningPart = z.infer<typeof ReasoningPart>
@@ -82,7 +82,7 @@ export namespace Message {
       type: z.literal("tool-invocation"),
       toolInvocation: ToolInvocation,
     })
-    .openapi({
+    .meta({
       ref: "ToolInvocationPart",
     })
   export type ToolInvocationPart = z.infer<typeof ToolInvocationPart>
@@ -93,9 +93,9 @@ export namespace Message {
       sourceId: z.string(),
       url: z.string(),
       title: z.string().optional(),
-      providerMetadata: z.record(z.any()).optional(),
+      providerMetadata: z.record(z.string(), z.any()).optional(),
     })
-    .openapi({
+    .meta({
       ref: "SourceUrlPart",
     })
   export type SourceUrlPart = z.infer<typeof SourceUrlPart>
@@ -107,7 +107,7 @@ export namespace Message {
       filename: z.string().optional(),
       url: z.string(),
     })
-    .openapi({
+    .meta({
       ref: "FilePart",
     })
   export type FilePart = z.infer<typeof FilePart>
@@ -116,14 +116,14 @@ export namespace Message {
     .object({
       type: z.literal("step-start"),
     })
-    .openapi({
+    .meta({
       ref: "StepStartPart",
     })
   export type StepStartPart = z.infer<typeof StepStartPart>
 
   export const MessagePart = z
     .discriminatedUnion("type", [TextPart, ReasoningPart, ToolInvocationPart, SourceUrlPart, FilePart, StepStartPart])
-    .openapi({
+    .meta({
       ref: "MessagePart",
     })
   export type MessagePart = z.infer<typeof MessagePart>
@@ -180,9 +180,9 @@ export namespace Message {
             .optional(),
           snapshot: z.string().optional(),
         })
-        .openapi({ ref: "MessageMetadata" }),
+        .meta({ ref: "MessageMetadata" }),
     })
-    .openapi({
+    .meta({
       ref: "Message",
     })
   export type Info = z.infer<typeof Info>

packages/opencode/src/session/prompt.ts

@@ -1,7 +1,7 @@
 import path from "path"
 import os from "os"
 import fs from "fs/promises"
-import z, { ZodSchema } from "zod"
+import z from "zod/v4"
 import { Identifier } from "../id/id"
 import { MessageV2 } from "./message-v2"
 import { Log } from "../util/log"
@@ -19,6 +19,7 @@ import {
   type StreamTextResult,
   LoadAPIKeyError,
   stepCountIs,
+  jsonSchema,
 } from "ai"
 import { SessionCompaction } from "./compaction"
 import { Instance } from "../project/instance"
@@ -95,7 +96,7 @@ export namespace SessionPrompt {
       .optional(),
     agent: z.string().optional(),
     system: z.string().optional(),
-    tools: z.record(z.boolean()).optional(),
+    tools: z.record(z.string(), z.boolean()).optional(),
     parts: z.array(
       z.discriminatedUnion("type", [
         MessageV2.TextPart.omit({
@@ -105,7 +106,7 @@ export namespace SessionPrompt {
           .partial({
             id: true,
           })
-          .openapi({
+          .meta({
             ref: "TextPartInput",
           }),
         MessageV2.FilePart.omit({
@@ -115,7 +116,7 @@ export namespace SessionPrompt {
           .partial({
             id: true,
           })
-          .openapi({
+          .meta({
             ref: "FilePartInput",
           }),
         MessageV2.AgentPart.omit({
@@ -125,7 +126,7 @@ export namespace SessionPrompt {
           .partial({
             id: true,
           })
-          .openapi({
+          .meta({
             ref: "AgentPartInput",
           }),
       ]),
@@ -393,10 +394,11 @@ export namespace SessionPrompt {
     )
     for (const item of await ToolRegistry.tools(input.providerID, input.modelID)) {
       if (Wildcard.all(item.id, enabledTools) === false) continue
+      const schema = ProviderTransform.schema(input.providerID, input.modelID, z.toJSONSchema(item.parameters))
       tools[item.id] = tool({
         id: item.id as any,
         description: item.description,
-        inputSchema: item.parameters as ZodSchema,
+        inputSchema: jsonSchema(schema as any),
         async execute(args, options) {
           await Plugin.trigger(
             "tool.execute.before",

packages/opencode/src/session/revert.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { Identifier } from "../id/id"
 import { Snapshot } from "../snapshot"
 import { MessageV2 } from "./message-v2"

packages/opencode/src/snapshot/index.ts

@@ -3,7 +3,7 @@ import path from "path"
 import fs from "fs/promises"
 import { Log } from "../util/log"
 import { Global } from "../global"
-import { z } from "zod"
+import z from "zod/v4"
 import { Config } from "../config/config"
 import { Instance } from "../project/instance"
 

packages/opencode/src/tool/bash.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { exec } from "child_process"
 
 import { Tool } from "./tool"

packages/opencode/src/tool/edit.ts

@@ -3,7 +3,7 @@
 // https://github.com/google-gemini/gemini-cli/blob/main/packages/core/src/utils/editCorrector.ts
 // https://github.com/cline/cline/blob/main/evals/diff-edits/diff-apply/diff-06-26-25.ts
 
-import { z } from "zod"
+import z from "zod/v4"
 import * as path from "path"
 import { Tool } from "./tool"
 import { LSP } from "../lsp"

packages/opencode/src/tool/glob.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import path from "path"
 import { Tool } from "./tool"
 import DESCRIPTION from "./glob.txt"

packages/opencode/src/tool/grep.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import { Ripgrep } from "../file/ripgrep"
 

packages/opencode/src/tool/invalid.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 
 export const InvalidTool = Tool.define("invalid", {

packages/opencode/src/tool/ls.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import * as path from "path"
 import DESCRIPTION from "./ls.txt"

packages/opencode/src/tool/lsp-diagnostics.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import path from "path"
 import { LSP } from "../lsp"

packages/opencode/src/tool/lsp-hover.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import path from "path"
 import { LSP } from "../lsp"

packages/opencode/src/tool/multiedit.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import { EditTool } from "./edit"
 import DESCRIPTION from "./multiedit.txt"

packages/opencode/src/tool/patch.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import * as path from "path"
 import * as fs from "fs/promises"
 import { Tool } from "./tool"

packages/opencode/src/tool/read.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import * as fs from "fs"
 import * as path from "path"
 import { Tool } from "./tool"

packages/opencode/src/tool/registry.ts

@@ -1,4 +1,4 @@
-import z from "zod"
+import z from "zod/v4"
 import { BashTool } from "./bash"
 import { EditTool } from "./edit"
 import { GlobTool } from "./glob"
@@ -124,35 +124,13 @@ export namespace ToolRegistry {
     return allTools().map((t) => t.id)
   }
 
-  export async function tools(providerID: string, _modelID: string) {
+  export async function tools(_providerID: string, _modelID: string) {
     const result = await Promise.all(
       allTools().map(async (t) => ({
         id: t.id,
         ...(await t.init()),
       })),
     )
-
-    if (providerID === "openai") {
-      return result.map((t) => ({
-        ...t,
-        parameters: optionalToNullable(t.parameters as unknown as z.ZodTypeAny),
-      }))
-    }
-
-    if (providerID === "azure") {
-      return result.map((t) => ({
-        ...t,
-        parameters: optionalToNullable(t.parameters as unknown as z.ZodTypeAny),
-      }))
-    }
-
-    if (providerID === "google") {
-      return result.map((t) => ({
-        ...t,
-        parameters: sanitizeGeminiParameters(t.parameters as unknown as z.ZodTypeAny),
-      }))
-    }
-
     return result
   }
 
@@ -178,93 +156,4 @@ export namespace ToolRegistry {
 
     return result
   }
-
-  function sanitizeGeminiParameters(schema: z.ZodTypeAny, visited = new Set()): z.ZodTypeAny {
-    if (!schema || visited.has(schema)) {
-      return schema
-    }
-    visited.add(schema)
-
-    if (schema instanceof z.ZodDefault) {
-      const innerSchema = schema.removeDefault()
-      // Handle Gemini's incompatibility with `default` on `anyOf` (unions).
-      if (innerSchema instanceof z.ZodUnion) {
-        // The schema was `z.union(...).default(...)`, which is not allowed.
-        // We strip the default and return the sanitized union.
-        return sanitizeGeminiParameters(innerSchema, visited)
-      }
-      // Otherwise, the default is on a regular type, which is allowed.
-      // We recurse on the inner type and then re-apply the default.
-      return sanitizeGeminiParameters(innerSchema, visited).default(schema._def.defaultValue())
-    }
-
-    if (schema instanceof z.ZodOptional) {
-      return z.optional(sanitizeGeminiParameters(schema.unwrap(), visited))
-    }
-
-    if (schema instanceof z.ZodObject) {
-      const newShape: Record<string, z.ZodTypeAny> = {}
-      for (const [key, value] of Object.entries(schema.shape)) {
-        newShape[key] = sanitizeGeminiParameters(value as z.ZodTypeAny, visited)
-      }
-      return z.object(newShape)
-    }
-
-    if (schema instanceof z.ZodArray) {
-      return z.array(sanitizeGeminiParameters(schema.element, visited))
-    }
-
-    if (schema instanceof z.ZodUnion) {
-      // This schema corresponds to `anyOf` in JSON Schema.
-      // We recursively sanitize each option in the union.
-      const sanitizedOptions = schema.options.map((option: z.ZodTypeAny) => sanitizeGeminiParameters(option, visited))
-      return z.union(sanitizedOptions as [z.ZodTypeAny, z.ZodTypeAny, ...z.ZodTypeAny[]])
-    }
-
-    if (schema instanceof z.ZodString) {
-      const newSchema = z.string({ description: schema.description })
-      const safeChecks = ["min", "max", "length", "regex", "startsWith", "endsWith", "includes", "trim"]
-      // rome-ignore lint/suspicious/noExplicitAny: <explanation>
-      ;(newSchema._def as any).checks = (schema._def as z.ZodStringDef).checks.filter((check) =>
-        safeChecks.includes(check.kind),
-      )
-      return newSchema
-    }
-
-    return schema
-  }
-
-  function optionalToNullable(schema: z.ZodTypeAny): z.ZodTypeAny {
-    if (schema instanceof z.ZodObject) {
-      const shape = schema.shape
-      const newShape: Record<string, z.ZodTypeAny> = {}
-
-      for (const [key, value] of Object.entries(shape)) {
-        const zodValue = value as z.ZodTypeAny
-        if (zodValue instanceof z.ZodOptional) {
-          newShape[key] = zodValue.unwrap().nullable()
-        } else {
-          newShape[key] = optionalToNullable(zodValue)
-        }
-      }
-
-      return z.object(newShape)
-    }
-
-    if (schema instanceof z.ZodArray) {
-      return z.array(optionalToNullable(schema.element))
-    }
-
-    if (schema instanceof z.ZodUnion) {
-      return z.union(
-        schema.options.map((option: z.ZodTypeAny) => optionalToNullable(option)) as [
-          z.ZodTypeAny,
-          z.ZodTypeAny,
-          ...z.ZodTypeAny[],
-        ],
-      )
-    }
-
-    return schema
-  }
 }

packages/opencode/src/tool/task.ts

@@ -1,6 +1,6 @@
 import { Tool } from "./tool"
 import DESCRIPTION from "./task.txt"
-import { z } from "zod"
+import z from "zod/v4"
 import { Session } from "../session"
 import { Bus } from "../bus"
 import { MessageV2 } from "../session/message-v2"

packages/opencode/src/tool/todo.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import DESCRIPTION_WRITE from "./todowrite.txt"
 import { Instance } from "../project/instance"

packages/opencode/src/tool/tool.ts

@@ -1,4 +1,4 @@
-import type { StandardSchemaV1 } from "@standard-schema/spec"
+import z from "zod/v4"
 
 export namespace Tool {
   interface Metadata {
@@ -13,13 +13,13 @@ export namespace Tool {
     extra?: { [key: string]: any }
     metadata(input: { title?: string; metadata?: M }): void
   }
-  export interface Info<Parameters extends StandardSchemaV1 = StandardSchemaV1, M extends Metadata = Metadata> {
+  export interface Info<Parameters extends z.ZodType = z.ZodType, M extends Metadata = Metadata> {
     id: string
     init: () => Promise<{
       description: string
       parameters: Parameters
       execute(
-        args: StandardSchemaV1.InferOutput<Parameters>,
+        args: z.infer<Parameters>,
         ctx: Context,
       ): Promise<{
         title: string
@@ -29,7 +29,7 @@ export namespace Tool {
     }>
   }
 
-  export function define<Parameters extends StandardSchemaV1, Result extends Metadata>(
+  export function define<Parameters extends z.ZodType, Result extends Metadata>(
     id: string,
     init: Info<Parameters, Result>["init"] | Awaited<ReturnType<Info<Parameters, Result>["init"]>>,
   ): Info<Parameters, Result> {

packages/opencode/src/tool/webfetch.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import { Tool } from "./tool"
 import TurndownService from "turndown"
 import DESCRIPTION from "./webfetch.txt"

packages/opencode/src/tool/write.ts

@@ -1,4 +1,4 @@
-import { z } from "zod"
+import z from "zod/v4"
 import * as path from "path"
 import { Tool } from "./tool"
 import { LSP } from "../lsp"

packages/opencode/src/util/error.ts

@@ -1,19 +1,19 @@
-import { z, type ZodSchema } from "zod"
+import z from "zod/v4"
 // import { Log } from "./log"
 
 // const log = Log.create()
 
 export abstract class NamedError extends Error {
-  abstract schema(): ZodSchema
+  abstract schema(): z.core.$ZodType
   abstract toObject(): { name: string; data: any }
 
-  static create<Name extends string, Data extends ZodSchema>(name: Name, data: Data) {
+  static create<Name extends string, Data extends z.core.$ZodType>(name: Name, data: Data) {
     const schema = z
       .object({
         name: z.literal(name),
         data,
       })
-      .openapi({
+      .meta({
         ref: name,
       })
     const result = class extends NamedError {

packages/opencode/src/util/log.ts

@@ -1,10 +1,10 @@
 import path from "path"
 import fs from "fs/promises"
 import { Global } from "../global"
-import z from "zod"
+import z from "zod/v4"
 
 export namespace Log {
-  export const Level = z.enum(["DEBUG", "INFO", "WARN", "ERROR"]).openapi({ ref: "LogLevel", description: "Log level" })
+  export const Level = z.enum(["DEBUG", "INFO", "WARN", "ERROR"]).meta({ ref: "LogLevel", description: "Log level" })
   export type Level = z.infer<typeof Level>
 
   const levelPriority: Record<Level, number> = {

packages/opencode/test/tool/register.test.ts

@@ -1,4 +1,3 @@
-import "zod-openapi/extend"
 import { describe, expect, test } from "bun:test"
 import path from "path"
 import os from "os"