feat(llm): provider packages own model request construction

Provider packages in @opencode-ai/llm/providers/* now implement a uniform
ProviderPackage contract: model(modelID, settings) => Model. SessionRunnerModel
becomes provider-agnostic: it resolves a package specifier, folds catalog
settings, credentials, and transport overlays into one Settings object, and
delegates request construction to the package.

- llm: add ProviderPackage (Settings, Definition, define), flat model(id,
  config) constructors on the openai-responses, anthropic-messages, and
  openai-compatible-chat protocols, contract-shaped model exports on the
  openai, anthropic, and openai-compatible providers, and a new
  providers/openai/codex entry point that targets the ChatGPT codex backend
  and sets the chatgpt-account-id header from settings.accountID.
- schema: Provider.Native gains optional package.
- core: SessionRunnerModel loads packages through a static built-in map
  (dynamic import for foreign specifiers) and applies one settings fold;
  the ChatGPT conditional is deleted from the runner. The OpenAI plugin's
  catalog transform now assigns the codex package to eligible models when a
  ChatGPT connection is active, alongside the existing eligibility and cost
  rewrites.
- llm schema: hoist ToolResultValue union out of its Object.assign self
  reference; the previous shape only typechecked under lucky check ordering
  and broke under core's typecheck with the new import graph.

Closes #34765

packages/core/src/plugin/provider/openai.ts

@@ -1,9 +1,10 @@
 import { createServer } from "node:http"
 import type { IntegrationOAuthMethodRegistration } from "@opencode-ai/plugin/v2/effect/integration"
 import { define } from "@opencode-ai/plugin/v2/effect/plugin"
-import { Deferred, Effect } from "effect"
+import { Deferred, Effect, Stream } from "effect"
 import type { Scope } from "effect"
 import { Credential } from "../../credential"
+import { EventV2 } from "../../event"
 import { InstallationVersion } from "../../installation/version"
 import { Integration } from "../../integration"
 import { ModelV2 } from "../../model"
@@ -17,6 +18,7 @@ const callbackPort = 1455
 const pollingSafetyMargin = 3000
 const browserMethodID = Integration.MethodID.make("chatgpt-browser")
 const headlessMethodID = Integration.MethodID.make("chatgpt-headless")
+const codexPackage = "@opencode-ai/llm/providers/openai/codex"
 
 type Pkce = {
   verifier: string
@@ -154,24 +156,55 @@ const headless = {
 export const OpenAIPlugin = define({
   id: "openai",
   effect: Effect.fn(function* (ctx) {
+    const events = yield* EventV2.Service
     yield* ctx.integration.transform((draft) => {
       draft.method.update(browser)
       draft.method.update(headless)
     })
     yield* ctx.catalog.transform(
       Effect.fn(function* (evt) {
+        const connection = yield* ctx.integration.connection.active("openai")
+        const credential = connection
+          ? yield* ctx.integration.connection.resolve(connection).pipe(Effect.catch(() => Effect.succeed(undefined)))
+          : undefined
+        const chatgpt = isChatGPT(credential)
         for (const item of evt.provider.list()) {
           if (item.provider.api.type !== "aisdk") continue
           if (item.provider.api.package !== "@ai-sdk/openai") continue
-          if (!item.models.has(ModelV2.ID.make("gpt-5-chat-latest"))) continue
-          evt.model.update(item.provider.id, ModelV2.ID.make("gpt-5-chat-latest"), (model) => {
-            // OpenAIPlugin sends OpenAI models through Responses; this alias is a
-            // chat-completions-only model, so hide it only from OpenAI's catalog.
-            model.enabled = false
-          })
+          if (item.models.has(ModelV2.ID.make("gpt-5-chat-latest"))) {
+            evt.model.update(item.provider.id, ModelV2.ID.make("gpt-5-chat-latest"), (model) => {
+              // OpenAIPlugin sends OpenAI models through Responses; this alias is a
+              // chat-completions-only model, so hide it only from OpenAI's catalog.
+              model.enabled = false
+            })
+          }
+          if (!chatgpt) continue
+          for (const model of item.models.values()) {
+            evt.model.update(item.provider.id, model.id, (draft) => {
+              if (!eligible(draft)) {
+                draft.enabled = false
+                return
+              }
+              draft.cost = draft.cost.map((cost) => ({ ...cost, input: 0, output: 0, cache: { read: 0, write: 0 } }))
+              draft.api = {
+                type: "native",
+                id: draft.api.id,
+                package: codexPackage,
+                settings:
+                  draft.api.type === "aisdk"
+                    ? { ...item.provider.api.settings, ...draft.api.settings }
+                    : draft.api.settings,
+              }
+            })
+          }
         }
       }),
     )
+    yield* events.subscribe(Integration.Event.ConnectionUpdated).pipe(
+      Stream.filter((event) => event.data.integrationID === Integration.ID.make("openai")),
+      Stream.runForEach(() => ctx.catalog.reload()),
+      Effect.forkScoped({ startImmediately: true }),
+    )
     yield* ctx.aisdk.sdk(
       Effect.fn(function* (evt) {
         if (evt.package !== "@ai-sdk/openai") return
@@ -269,16 +302,27 @@ function authorizeURL(redirect: string, pkce: Pkce, state: string) {
     codex_cli_simplified_flow: "true",
     state,
     originator: "opencode",
-  })}`
+  }).toString()}`
 }
 
 function extractAccountID(tokens: TokenResponse) {
   return claim(tokens.id_token) ?? claim(tokens.access_token)
 }
 
+function isChatGPT(credential: { readonly type: string; readonly methodID?: string } | undefined) {
+  return (
+    credential?.type === "oauth" &&
+    (credential.methodID === browserMethodID || credential.methodID === headlessMethodID)
+  )
+}
+
+function eligible(model: { readonly id: string }) {
+  return model.id.includes("codex")
+}
+
 function claim(token: string) {
   const part = token.split(".")[1]
-  if (!part) return
+  if (!part) return undefined
   try {
     const claims = JSON.parse(Buffer.from(part, "base64url").toString()) as Claims
     return (
@@ -287,6 +331,6 @@ function claim(token: string) {
       claims.organizations?.[0]?.id
     )
   } catch {
-    return
+    return undefined
   }
 }

packages/core/src/provider.ts

@@ -1,7 +1,9 @@
 export * as ProviderV2 from "./provider"
 
-import { Types } from "effect"
+import { Effect, Schema, Types } from "effect"
 import { Provider } from "@opencode-ai/schema/provider"
+import { ProviderPackage } from "@opencode-ai/llm/provider-package"
+import { Anthropic, OpenAI, OpenAICodex, OpenAICompatible } from "@opencode-ai/llm/providers"
 
 export const ID = Provider.ID
 export type ID = typeof ID.Type
@@ -23,3 +25,44 @@ export const Info = Provider.Info
 export type Info = Provider.Info
 
 export type MutableInfo = Omit<Types.DeepMutable<Info>, "api"> & { api: MutableApi }
+
+export class PackageLoadError extends Schema.TaggedErrorClass<PackageLoadError>()("ProviderV2.PackageLoadError", {
+  specifier: Schema.String,
+  reason: Schema.String,
+}) {
+  override get message() {
+    return `Failed to load provider package ${this.specifier}: ${this.reason}`
+  }
+}
+
+type PackageModule = { readonly model: ProviderPackage.Definition["model"] }
+
+const builtins: Record<string, PackageModule> = {
+  "@opencode-ai/llm/providers/openai": OpenAI,
+  "@opencode-ai/llm/providers/anthropic": Anthropic,
+  "@opencode-ai/llm/providers/openai-compatible": OpenAICompatible,
+  "@opencode-ai/llm/providers/openai/codex": OpenAICodex,
+}
+
+export const loadPackage = (
+  specifier: string,
+): Effect.Effect<ProviderPackage.Definition["model"], PackageLoadError> => {
+  const builtin = builtins[specifier]
+  if (builtin) return Effect.succeed(builtin.model)
+  return Effect.tryPromise({
+    try: () => import(specifier),
+    catch: (cause) =>
+      new PackageLoadError({ specifier, reason: cause instanceof Error ? cause.message : String(cause) }),
+  }).pipe(
+    Effect.flatMap((module) => {
+      if (hasModel(module)) return Effect.succeed(module.model)
+      return Effect.fail(new PackageLoadError({ specifier, reason: "missing model export" }))
+    }),
+  )
+}
+
+export const load = loadPackage
+
+function hasModel(module: unknown): module is PackageModule {
+  return typeof module === "object" && module !== null && "model" in module && typeof module.model === "function"
+}

packages/core/src/session/runner/model.ts

@@ -1,11 +1,7 @@
 export * as SessionRunnerModel from "./model"
 
 import { makeLocationNode } from "../../effect/app-node"
-import { type Model } from "@opencode-ai/llm"
-import * as AnthropicMessages from "@opencode-ai/llm/protocols/anthropic-messages"
-import * as OpenAICompatibleChat from "@opencode-ai/llm/protocols/openai-compatible-chat"
-import * as OpenAIResponses from "@opencode-ai/llm/protocols/openai-responses"
-import { Auth, type AnyRoute } from "@opencode-ai/llm/route"
+import { Model } from "@opencode-ai/llm"
 import { Context, Effect, Layer, Schema } from "effect"
 import { produce } from "immer"
 import { Catalog } from "../../catalog"
@@ -69,6 +65,7 @@ export type Error =
   | ModelUnavailableError
   | VariantUnavailableError
   | UnsupportedApiError
+  | ProviderV2.PackageLoadError
   | Integration.AuthorizationError
 
 export interface Interface {
@@ -80,27 +77,6 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/v2
 /** Test or embedding seam for supplying a model resolver directly. */
 export const layerWith = (resolve: Interface["resolve"]) => Layer.succeed(Service, Service.of({ resolve }))
 
-const apiKey = (model: ModelV2.Info, credential?: Credential.Value) => {
-  if (credential?.type === "key") return Auth.value(credential.key)
-  if (credential?.type === "oauth") return Auth.value(credential.access)
-  const value = model.request.body.apiKey ?? model.api.settings?.apiKey
-  if (typeof value === "string") return Auth.value(value)
-}
-
-const withDefaults = (model: ModelV2.Info, route: AnyRoute) => {
-  const body = model.request.body
-  const httpBody = Object.hasOwn(body, "apiKey")
-    ? Object.fromEntries(Object.entries(body).filter(([key]) => key !== "apiKey"))
-    : body
-  return route.with({
-    provider: model.providerID,
-    endpoint: model.api.url === undefined ? undefined : { baseURL: model.api.url },
-    headers: model.request.headers,
-    http: { body: httpBody },
-    limits: { context: model.limit.context, output: model.limit.output },
-  })
-}
-
 const withVariant = (
   model: ModelV2.Info,
   variantID: ModelV2.VariantID | undefined,
@@ -131,52 +107,99 @@ const apiName = (model: ModelV2.Info) =>
 export const fromCatalogModel = (
   model: ModelV2.Info,
   credential?: Credential.Value,
-): Effect.Effect<Model, UnsupportedApiError> => {
+): Effect.Effect<Model, UnsupportedApiError | ProviderV2.PackageLoadError> => {
   const resolved =
     credential?.type !== "key" || credential.metadata === undefined
       ? model
       : produce(model, (draft) => {
           Object.assign(draft.request.body, credential.metadata)
         })
-  const key = apiKey(resolved, credential)
-  if (resolved.api.type === "aisdk" && resolved.api.package === "@ai-sdk/openai") {
-    return Effect.succeed(
-      withDefaults(resolved, OpenAIResponses.route)
-        .with({ auth: key === undefined ? Auth.none : Auth.bearer(key) })
-        .model({ id: resolved.api.id }),
-    )
-  }
-  if (resolved.api.type === "aisdk" && resolved.api.package === "@ai-sdk/anthropic") {
-    return Effect.succeed(
-      withDefaults(resolved, AnthropicMessages.route)
-        .with({ auth: key === undefined ? Auth.none : Auth.header("x-api-key", key) })
-        .model({ id: resolved.api.id }),
-    )
-  }
-  if (resolved.api.type === "aisdk" && resolved.api.package === "@ai-sdk/openai-compatible" && resolved.api.url) {
-    return Effect.succeed(
-      withDefaults(resolved, OpenAICompatibleChat.route)
-        .with({ auth: key === undefined ? Auth.none : Auth.bearer(key) })
-        .model({ id: resolved.api.id }),
-    )
-  }
-  return Effect.fail(
-    new UnsupportedApiError({
-      providerID: resolved.providerID,
-      modelID: resolved.id,
-      api: apiName(resolved),
-    }),
+  return packageSpecifier(resolved).pipe(
+    Effect.flatMap((specifier) =>
+      ProviderV2.loadPackage(specifier).pipe(
+        Effect.map((load) => {
+          const selected = load(resolved.api.id ?? resolved.id, {
+            ...resolved.api.settings,
+            ...(credential?.type === "oauth" ? credential.metadata : undefined),
+            baseURL: resolved.api.url ?? settingsString(resolved.api.settings, "baseURL"),
+            apiKey: apiKey(resolved, credential),
+            providerOptions: requestSettings(resolved.request),
+            headers: resolved.request.headers,
+            body: stripApiKey(resolved.request.body),
+            limits: { context: resolved.limit.context, output: resolved.limit.output },
+          })
+          return Model.update(selected, {
+            provider: resolved.providerID,
+            route: selected.route.with({ provider: resolved.providerID }),
+          })
+        }),
+      ),
+    ),
   )
 }
 
 export const resolve = (session: SessionSchema.Info, model: ModelV2.Info, credential?: Credential.Value) =>
   withVariant(model, session.model?.variant).pipe(Effect.flatMap((model) => fromCatalogModel(model, credential)))
 
+/** Legacy aisdk catalog entries dispatch to the equivalent native provider packages. */
+const aisdkPackages: Record<string, string | undefined> = {
+  "@ai-sdk/openai": "@opencode-ai/llm/providers/openai",
+  "@ai-sdk/anthropic": "@opencode-ai/llm/providers/anthropic",
+  "@ai-sdk/openai-compatible": "@opencode-ai/llm/providers/openai-compatible",
+}
+
 export const supported = (model: ModelV2.Info) =>
-  model.api.type === "aisdk" &&
-  (model.api.package === "@ai-sdk/openai" ||
-    model.api.package === "@ai-sdk/anthropic" ||
-    (model.api.package === "@ai-sdk/openai-compatible" && model.api.url !== undefined))
+  (model.api.type === "native" && model.api.package !== undefined) ||
+  (model.api.type === "aisdk" &&
+    aisdkPackages[model.api.package] !== undefined &&
+    // The openai-compatible package has no default endpoint; a URL is required.
+    (model.api.package !== "@ai-sdk/openai-compatible" || model.api.url !== undefined))
+
+const packageSpecifier = (model: ModelV2.Info): Effect.Effect<string, UnsupportedApiError> => {
+  if (supported(model)) {
+    if (model.api.type === "native" && model.api.package !== undefined) return Effect.succeed(model.api.package)
+    const specifier = model.api.type === "aisdk" ? aisdkPackages[model.api.package] : undefined
+    if (specifier !== undefined) return Effect.succeed(specifier)
+  }
+  return Effect.fail(
+    new UnsupportedApiError({
+      providerID: model.providerID,
+      modelID: model.id,
+      api: apiName(model),
+    }),
+  )
+}
+
+const apiKey = (model: ModelV2.Info, credential?: Credential.Value) => {
+  if (credential?.type === "key") return credential.key
+  if (credential?.type === "oauth") return credential.access
+  const value = model.request.body.apiKey ?? model.api.settings?.apiKey
+  if (typeof value === "string") return value
+  return undefined
+}
+
+const stripApiKey = (body: ModelV2.Info["request"]["body"]) => {
+  if (!Object.hasOwn(body, "apiKey")) return body
+  return Object.fromEntries(Object.entries(body).filter(([key]) => key !== "apiKey"))
+}
+
+const requestSettings = (request: ModelV2.Info["request"]) => {
+  if (!("settings" in request)) return undefined
+  const settings = request.settings
+  if (!isRecord(settings)) return undefined
+  if (Object.keys(settings).length === 0) return undefined
+  return settings
+}
+
+const settingsString = (settings: ModelV2.Info["api"]["settings"], key: string) => {
+  const value = settings?.[key]
+  if (typeof value === "string") return value
+  return undefined
+}
+
+function isRecord(value: unknown): value is Readonly<Record<string, unknown>> {
+  return typeof value === "object" && value !== null && !Array.isArray(value)
+}
 
 /** Resolves models from the catalog belonging to the current Location runtime. */
 export const locationLayer = Layer.effect(