diff --git a/packages/ai/src/route/transport/http.ts b/packages/ai/src/route/transport/http.ts
index c8f94d1a7a1..5e330f61d5c 100644
--- a/packages/ai/src/route/transport/http.ts
+++ b/packages/ai/src/route/transport/http.ts
@@ -1,11 +1,19 @@
-import { Effect } from "effect"
+import { Clock, Duration, Effect, Stream } from "effect"
 import { Headers, HttpClientRequest } from "effect/unstable/http"
 import { Auth } from "../auth.js"
 import { render as renderEndpoint } from "../endpoint.js"
 import { Framing } from "../framing.js"
 import type { HttpMiddleware, Transport, TransportPrepareInput } from "./index.js"
 import * as ProviderShared from "../../protocols/shared.js"
-import { mergeJsonRecords, type LLMRequest } from "../../schema/index.js"
+import {
+  AIError,
+  DEFAULT_HTTP_TIMEOUT_MS,
+  mergeJsonRecords,
+  TransportError,
+  type HttpContext,
+  type HttpTimeout,
+  type LLMRequest,
+} from "../../schema/index.js"
 import { RequestExecutor } from "../executor.js"
 
 export type JsonRequestInput<Body> = TransportPrepareInput<Body>
@@ -87,17 +95,53 @@ export const httpJson = <Body, Frame>(input: HttpJsonInput<Body, Frame>): HttpJs
         middleware: prepareInput.middleware,
       }
     }),
-  execute: (prepared, _request, runtime) =>
+  execute: (prepared, request, runtime) =>
     Effect.gen(function* () {
-      const response = yield* runtime.http.execute(prepared.request, prepared.middleware)
+      const timeout = (operation: "request" | "read", message: string, http?: HttpContext) =>
+        new AIError({
+          reason: new TransportError({
+            message,
+            transport: "http",
+            operation,
+            code: "Timeout",
+            url: prepared.request.url,
+            http,
+          }),
+        })
+      const started = yield* Clock.currentTimeMillis
+      // Unlike the header and chunk limits, the whole-request budget has no default.
+      const total = request.http?.timeout ? Duration.millis(request.http.timeout) : Duration.infinity
+      const response = yield* runtime.http.execute(prepared.request, prepared.middleware).pipe(
+        Effect.timeoutOrElse({
+          duration: Duration.min(timeoutDuration(request.http?.headerTimeout), total),
+          orElse: () => timeout("request", "Timed out waiting for response headers"),
+        }),
+      )
+      const http = RequestExecutor.responseHttp(response)
+      const remaining = Duration.subtract(total, Duration.millis((yield* Clock.currentTimeMillis) - started))
       return {
-        frames: prepared.framing.frame(RequestExecutor.responseStream(response)),
-        http: RequestExecutor.responseHttp(response),
+        frames: prepared.framing.frame(
+          RequestExecutor.responseStream(response).pipe(
+            Stream.timeoutOrElse({
+              duration: timeoutDuration(request.http?.chunkTimeout),
+              orElse: () => Stream.fail(timeout("read", "Timed out waiting for response data", http)),
+            }),
+            Stream.interruptWhen(
+              Effect.sleep(remaining).pipe(
+                Effect.andThen(Effect.fail(timeout("read", "Timed out waiting for the response to complete", http))),
+              ),
+            ),
+          ),
+        ),
+        http,
         body: prepared.framing.body,
       }
     }),
 })
 
+const timeoutDuration = (value: HttpTimeout | undefined) =>
+  value === false ? Duration.infinity : Duration.millis(value ?? DEFAULT_HTTP_TIMEOUT_MS)
+
 export const sseJson = {
   id: "http-json/sse",
   with: <Body>() => httpJson<Body, string>({ framing: Framing.sse }),
diff --git a/packages/ai/src/schema/options.ts b/packages/ai/src/schema/options.ts
index 88429a2d9a8..615a4339369 100644
--- a/packages/ai/src/schema/options.ts
+++ b/packages/ai/src/schema/options.ts
@@ -48,10 +48,23 @@ export const mergeProviderOptions = (
   ...items: ReadonlyArray<ProviderOptions | undefined>
 ): ProviderOptions | undefined => mergeJsonRecords(...items)
 
+/** Milliseconds for an HTTP timeout, or `false` to disable it. */
+export const HttpTimeout = Schema.Union([Schema.Number.check(Schema.isGreaterThan(0)), Schema.Literal(false)])
+export type HttpTimeout = Schema.Schema.Type<typeof HttpTimeout>
+
+/** Applied to `headerTimeout` and `chunkTimeout` when a request leaves them unset. */
+export const DEFAULT_HTTP_TIMEOUT_MS = 300_000
+
 export class HttpOptions extends Schema.Class<HttpOptions>("AI.HttpOptions")({
   body: Schema.optional(JsonSchema),
   headers: Schema.optional(Schema.Record(Schema.String, Schema.String)),
   query: Schema.optional(Schema.Record(Schema.String, Schema.String)),
+  /** Time allowed for the whole request, from send until the response completes. Unbounded when unset. */
+  timeout: Schema.optional(HttpTimeout),
+  /** Time allowed for response headers to arrive. */
+  headerTimeout: Schema.optional(HttpTimeout),
+  /** Time allowed between streamed response chunks once headers have arrived. */
+  chunkTimeout: Schema.optional(HttpTimeout),
 }) {}
 
 export namespace HttpOptions {
@@ -70,8 +83,12 @@ export const mergeHttpOptions = (...items: ReadonlyArray<HttpOptions | undefined
   const body = mergeJsonRecords(...items.map((item) => item?.body))
   const headers = mergeStringRecords(...items.map((item) => item?.headers))
   const query = mergeStringRecords(...items.map((item) => item?.query))
-  if (!body && !headers && !query) return undefined
-  return new HttpOptions({ body, headers, query })
+  const timeout = items.findLast((item) => item?.timeout !== undefined)?.timeout
+  const headerTimeout = items.findLast((item) => item?.headerTimeout !== undefined)?.headerTimeout
+  const chunkTimeout = items.findLast((item) => item?.chunkTimeout !== undefined)?.chunkTimeout
+  if (!body && !headers && !query && timeout === undefined && headerTimeout === undefined && chunkTimeout === undefined)
+    return undefined
+  return new HttpOptions({ body, headers, query, timeout, headerTimeout, chunkTimeout })
 }
 
 export class GenerationOptions extends Schema.Class<GenerationOptions>("LLM.GenerationOptions")({
diff --git a/packages/ai/test/http-timeout.test.ts b/packages/ai/test/http-timeout.test.ts
new file mode 100644
index 00000000000..6b45a807007
--- /dev/null
+++ b/packages/ai/test/http-timeout.test.ts
@@ -0,0 +1,169 @@
+import { describe, expect } from "bun:test"
+import { Deferred, Effect, Fiber } from "effect"
+import * as TestClock from "effect/testing/TestClock"
+import { HttpOptions, LLM, mergeHttpOptions } from "../src/index.js"
+import { LLMClient } from "../src/route.js"
+import { configure } from "../src/providers/openai.js"
+import { dynamicResponse } from "./lib/http.js"
+import { deltaChunk, finishChunk } from "./lib/openai-chunks.js"
+import { sseEvents, sseRaw } from "./lib/sse.js"
+import { it } from "./lib/effect.js"
+
+const model = configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).chat("gpt-4.1-mini")
+const SSE = { headers: { "content-type": "text/event-stream" } }
+
+const silentServer = dynamicResponse(() => Effect.never)
+
+const slowHeadersServer = dynamicResponse((input) =>
+  Effect.sleep("10 minutes").pipe(
+    Effect.as(input.respond(sseEvents(deltaChunk({ role: "assistant", content: "Hi" }), finishChunk("stop")), SSE)),
+  ),
+)
+
+// Sends one chunk, then stalls until `resume` releases the rest of the body.
+const stalledServer = Effect.gen(function* () {
+  const stalled = yield* Deferred.make<void>()
+  let resume = () => {}
+  const released = new Promise<void>((resolve) => {
+    resume = resolve
+  })
+  const encoder = new TextEncoder()
+  const layer = dynamicResponse((input) =>
+    Effect.sync(() =>
+      input.respond(
+        new ReadableStream<Uint8Array>({
+          start(controller) {
+            controller.enqueue(encoder.encode(sseRaw(`data: ${JSON.stringify(deltaChunk({ content: "Hi" }))}`)))
+          },
+          async pull(controller) {
+            Deferred.doneUnsafe(stalled, Effect.void)
+            await released
+            controller.enqueue(encoder.encode(sseEvents(finishChunk("stop"))))
+            controller.close()
+          },
+        }),
+        SSE,
+      ),
+    ),
+  )
+  return { layer, stalled, resume: () => resume() }
+})
+
+describe("HTTP transport timeouts", () => {
+  it.effect("fails when response headers take longer than five minutes", () =>
+    Effect.gen(function* () {
+      const fiber = yield* LLMClient.generate(LLM.request({ model, prompt: "Hello" })).pipe(
+        Effect.provide(silentServer),
+        Effect.flip,
+        Effect.forkChild({ startImmediately: true }),
+      )
+      yield* TestClock.adjust("5 minutes")
+      const error = yield* Fiber.join(fiber)
+
+      expect(error.reason).toMatchObject({
+        _tag: "Transport",
+        transport: "http",
+        operation: "request",
+        code: "Timeout",
+      })
+    }),
+  )
+
+  it.effect("fails when the response body stalls for five minutes", () =>
+    Effect.gen(function* () {
+      const server = yield* stalledServer
+      const fiber = yield* LLMClient.generate(LLM.request({ model, prompt: "Hello" })).pipe(
+        Effect.provide(server.layer),
+        Effect.flip,
+        Effect.forkChild({ startImmediately: true }),
+      )
+      yield* Deferred.await(server.stalled)
+      yield* Effect.yieldNow
+      yield* TestClock.adjust("5 minutes")
+      const error = yield* Fiber.join(fiber)
+
+      expect(error.reason).toMatchObject({ _tag: "Transport", transport: "http", operation: "read", code: "Timeout" })
+      expect(error.reason.http).toMatchObject({ status: 200 })
+    }),
+  )
+
+  it.effect("applies a configured header timeout", () =>
+    Effect.gen(function* () {
+      const fiber = yield* LLMClient.generate(
+        LLM.request({ model, prompt: "Hello", http: { headerTimeout: 1_000 } }),
+      ).pipe(Effect.provide(silentServer), Effect.flip, Effect.forkChild({ startImmediately: true }))
+      yield* TestClock.adjust("1 second")
+      const error = yield* Fiber.join(fiber)
+
+      expect(error.reason).toMatchObject({ _tag: "Transport", operation: "request", code: "Timeout" })
+    }),
+  )
+
+  it.effect("disables the header timeout with false", () =>
+    Effect.gen(function* () {
+      const fiber = yield* LLMClient.generate(
+        LLM.request({ model, prompt: "Hello", http: { headerTimeout: false } }),
+      ).pipe(Effect.provide(slowHeadersServer), Effect.forkChild({ startImmediately: true }))
+      yield* TestClock.adjust("10 minutes")
+      const response = yield* Fiber.join(fiber)
+
+      expect(response.text).toBe("Hi")
+    }),
+  )
+
+  it.effect("disables the chunk timeout with false", () =>
+    Effect.gen(function* () {
+      const server = yield* stalledServer
+      const fiber = yield* LLMClient.generate(
+        LLM.request({ model, prompt: "Hello", http: { chunkTimeout: false } }),
+      ).pipe(Effect.provide(server.layer), Effect.forkChild({ startImmediately: true }))
+      yield* Deferred.await(server.stalled)
+      yield* Effect.yieldNow
+      yield* TestClock.adjust("10 minutes")
+      server.resume()
+      const response = yield* Fiber.join(fiber)
+
+      expect(response.text).toBe("Hi")
+    }),
+  )
+
+  it.effect("applies a whole-request timeout while the body is still streaming", () =>
+    Effect.gen(function* () {
+      const server = yield* stalledServer
+      const fiber = yield* LLMClient.generate(
+        LLM.request({ model, prompt: "Hello", http: { timeout: 60_000, chunkTimeout: false } }),
+      ).pipe(Effect.provide(server.layer), Effect.flip, Effect.forkChild({ startImmediately: true }))
+      yield* Deferred.await(server.stalled)
+      yield* Effect.yieldNow
+      yield* TestClock.adjust("1 minute")
+      const error = yield* Fiber.join(fiber)
+
+      expect(error.reason).toMatchObject({ _tag: "Transport", operation: "read", code: "Timeout" })
+    }),
+  )
+
+  it.effect("bounds the header wait by a shorter whole-request timeout", () =>
+    Effect.gen(function* () {
+      const fiber = yield* LLMClient.generate(
+        LLM.request({ model, prompt: "Hello", http: { timeout: 1_000, headerTimeout: false } }),
+      ).pipe(Effect.provide(silentServer), Effect.flip, Effect.forkChild({ startImmediately: true }))
+      yield* TestClock.adjust("1 second")
+      const error = yield* Fiber.join(fiber)
+
+      expect(error.reason).toMatchObject({ _tag: "Transport", operation: "request", code: "Timeout" })
+    }),
+  )
+
+  it.effect("merges timeouts with later values winning", () =>
+    Effect.sync(() => {
+      const merged = mergeHttpOptions(
+        new HttpOptions({ timeout: 5_000, headerTimeout: 1_000, chunkTimeout: 2_000 }),
+        new HttpOptions({ headers: { a: "b" } }),
+        new HttpOptions({ chunkTimeout: false }),
+      )
+
+      expect(merged).toMatchObject({ headers: { a: "b" }, timeout: 5_000, headerTimeout: 1_000, chunkTimeout: false })
+      expect(mergeHttpOptions(new HttpOptions({}), undefined)).toBeUndefined()
+    }),
+  )
+})
diff --git a/packages/client/src/promise/generated/types.ts b/packages/client/src/promise/generated/types.ts
index 1a450e13981..7341f79490d 100644
--- a/packages/client/src/promise/generated/types.ts
+++ b/packages/client/src/promise/generated/types.ts
@@ -475,14 +475,16 @@ export type ConfigModelSettings = { compaction?: ProviderCompaction } & { [x: st
 
 export type ProviderSettings = {
   timeout?: number | false
-  chunkTimeout?: number
+  headerTimeout?: number | false
+  chunkTimeout?: number | false
   compaction?: ProviderCompaction
   transport?: ProviderTransport
 } & { [x: string]: any }
 
 export type ConfigProviderSettings = {
   timeout?: number | false
-  chunkTimeout?: number
+  headerTimeout?: number | false
+  chunkTimeout?: number | false
   compaction?: ProviderCompaction
   transport?: ProviderTransport
 } & { [x: string]: JsonValue | null }
diff --git a/packages/core/src/aisdk.ts b/packages/core/src/aisdk.ts
index cb27a55584c..4b9d5c8e928 100644
--- a/packages/core/src/aisdk.ts
+++ b/packages/core/src/aisdk.ts
@@ -128,23 +128,29 @@ function prepareOptions(model: RuntimeInfo, pkg: string) {
   }
 
   const customFetch = options.fetch
-  const chunkTimeout = options.chunkTimeout
+  const timeouts = Provider.timeouts(options)
+  delete options.headerTimeout
   delete options.chunkTimeout
   delete options.compaction
   delete options.transport
   options.fetch = async (input: Parameters<typeof fetch>[0], init?: RequestInit) => {
     const opts = { ...(init ?? {}) }
-    const signals = [
-      opts.signal,
-      typeof chunkTimeout === "number" && chunkTimeout > 0 ? new AbortController() : undefined,
-      options.timeout !== undefined && options.timeout !== null && options.timeout !== false
-        ? AbortSignal.timeout(options.timeout)
-        : undefined,
-    ].filter((item): item is AbortSignal | AbortController => item !== undefined && item !== null)
-    const chunkAbortCtl = signals.find((item): item is AbortController => item instanceof AbortController)
-    const abortSignals = signals.map((item) => (item instanceof AbortController ? item.signal : item))
-    if (abortSignals.length === 1) opts.signal = abortSignals[0]
-    if (abortSignals.length > 1) opts.signal = AbortSignal.any(abortSignals)
+    // A plain AbortSignal.timeout would keep running into the body stream, so the header limit uses
+    // a timer that is cleared once headers arrive. The whole-request limit is meant to span the body.
+    const headers = new AbortController()
+    const headerTimer =
+      timeouts.headerTimeout === false
+        ? undefined
+        : setTimeout(() => headers.abort(new Error(HEADER_TIMEOUT_MESSAGE)), timeouts.headerTimeout)
+    const chunks = new AbortController()
+    opts.signal = AbortSignal.any(
+      [
+        opts.signal,
+        headers.signal,
+        chunks.signal,
+        timeouts.timeout ? AbortSignal.timeout(timeouts.timeout) : undefined,
+      ].filter((item): item is AbortSignal => item !== undefined && item !== null),
+    )
 
     if (typeof opts.body === "string" && model.body !== undefined) {
       const decoded = Option.getOrUndefined(decodeJson(opts.body))
@@ -155,11 +161,13 @@ function prepareOptions(model: RuntimeInfo, pkg: string) {
 
     const send: Fetch = typeof customFetch === "function" ? customFetch : fetch
     const middleware = httpMiddleware.getStore()
-    const res = middleware
-      ? await throughMiddleware(middleware, send, input, { ...opts, timeout: false })
-      : await send(input, { ...opts, timeout: false })
-    if (!chunkAbortCtl || typeof chunkTimeout !== "number") return res
-    return wrapSSE(res, chunkTimeout, chunkAbortCtl)
+    const res = await (
+      middleware
+        ? throughMiddleware(middleware, send, input, { ...opts, timeout: false })
+        : send(input, { ...opts, timeout: false })
+    ).finally(() => clearTimeout(headerTimer))
+    if (timeouts.chunkTimeout === false) return res
+    return wrapSSE(res, timeouts.chunkTimeout, chunks)
   }
 
   return options
@@ -215,6 +223,8 @@ function throughMiddleware(
   )
 }
 
+const HEADER_TIMEOUT_MESSAGE = "Response headers timed out"
+
 export class InitError extends Schema.TaggedError<InitError>()("AISDK.InitError", {
   providerID: Provider.ID,
   cause: Schema.Defect(),
@@ -447,9 +457,17 @@ function requestSettings(settings: Readonly<Record<string, unknown>> | undefined
   const result = Object.fromEntries(
     Object.entries(settings).filter(
       ([key]) =>
-        !["apiKey", "authToken", "baseURL", "chunkTimeout", "compaction", "fetch", "timeout", "transport"].includes(
-          key,
-        ),
+        ![
+          "apiKey",
+          "authToken",
+          "baseURL",
+          "chunkTimeout",
+          "compaction",
+          "fetch",
+          "headerTimeout",
+          "timeout",
+          "transport",
+        ].includes(key),
     ),
   )
   return Object.keys(result).length === 0 ? undefined : result
@@ -951,7 +969,7 @@ const errorValue = (error: unknown) => (ProviderShared.isRecord(error) ? error.v
 
 // Runtime-generated network failure shapes. The codes mirror the AI SDK's own
 // Bun network error list in handleFetchError; the messages are undici's fetch
-// TypeError and stream termination strings plus our SSE chunk timeout error.
+// TypeError and stream termination strings plus our header and chunk timeout errors.
 // Unrecognized shapes still retry via the UnknownProvider default; this match
 // only adds transport semantics (continuation eligibility, display).
 const NETWORK_ERROR_CODES = new Set([
@@ -969,6 +987,7 @@ const NETWORK_ERROR_MESSAGES = new Set([
   "terminated",
   "other side closed",
   "sse read timed out",
+  HEADER_TIMEOUT_MESSAGE.toLowerCase(),
 ])
 
 const NativeErrorShape = Schema.Struct({
diff --git a/packages/core/src/model-resolver.ts b/packages/core/src/model-resolver.ts
index 56428b0cb5d..63a5cc0f2e1 100644
--- a/packages/core/src/model-resolver.ts
+++ b/packages/core/src/model-resolver.ts
@@ -1,7 +1,7 @@
 export * as ModelResolver from "./model-resolver.js"
 
 import { makeLocationNode } from "@opencode/util/effect/app-node"
-import { LanguageModel, ProviderConfigurationError } from "@opencode/ai"
+import { HttpOptions, LanguageModel, mergeHttpOptions, ProviderConfigurationError } from "@opencode/ai"
 import { Auth } from "@opencode/ai/route"
 import { Context, Effect, Layer, Schema, Struct } from "effect"
 import { AISDK } from "./aisdk.js"
@@ -122,8 +122,8 @@ export interface Resolved {
   readonly compaction?: Provider.Compaction
   /** Provider transport policy; omitted means HTTP. */
   readonly transport?: Provider.Transport
-  /** Milliseconds without streamed data before a WebSocket exchange fails. */
-  readonly chunkTimeout?: number
+  /** Milliseconds without streamed data before a WebSocket exchange fails; `false` disables the limit. */
+  readonly chunkTimeout?: number | false
 }
 
 export interface Interface {
@@ -237,6 +237,11 @@ const resolveCatalogModel = Effect.fn("ModelResolver.resolveCatalogModel")(funct
         compatibility: resolved.compatibility
           ? Object.assign({}, runtime.compatibility, resolved.compatibility)
           : runtime.compatibility,
+        // Timeouts are transport policy, so they land on the route's HTTP defaults instead of package settings.
+        defaults: {
+          ...runtime.defaults,
+          http: mergeHttpOptions(runtime.defaults?.http, new HttpOptions(Provider.timeouts(configured))),
+        },
       })
     },
     catch: (cause) =>
@@ -390,7 +395,7 @@ export const layer = Layer.effect(
         limit: selected.limit,
         compaction: runtimeInfo.settings?.compaction,
         transport: provider?.settings?.transport,
-        chunkTimeout: provider?.settings?.chunkTimeout,
+        chunkTimeout: Provider.timeout(provider?.settings?.chunkTimeout),
       }
     })
     return Service.of({
diff --git a/packages/core/src/provider.ts b/packages/core/src/provider.ts
index 9204837424d..dc2261735f5 100644
--- a/packages/core/src/provider.ts
+++ b/packages/core/src/provider.ts
@@ -1,10 +1,10 @@
 export * as Provider from "./provider.js"
 
-import { Context, Effect, Layer, Schema, Stream, Struct } from "effect"
+import { Context, Effect, Layer, Option, Schema, Stream, Struct } from "effect"
 import { Provider } from "@opencode/schema/provider"
 import { Model } from "@opencode/schema/model"
 import { makeLocationNode } from "@opencode/util/effect/app-node"
-import type { ProviderPackageDefinition } from "@opencode/ai"
+import { HttpTimeout, type ProviderPackageDefinition } from "@opencode/ai"
 import { isRecord } from "@opencode/ai/utils/record"
 import { Npm } from "@opencode/util/npm"
 import type { DeepMutable } from "./schema.js"
@@ -134,8 +134,8 @@ export const loadPackage = Effect.fn("Provider.loadPackage")(function* (input: s
 })
 
 /** opencode settings consumed in Core; native packages never receive them. */
-const CORE_KEYS = ["chunkTimeout", "compaction", "fetch", "timeout", "transport"] as const
-const PROVIDER_ONLY_KEYS = ["chunkTimeout", "timeout", "transport"] as const
+const CORE_KEYS = ["chunkTimeout", "compaction", "fetch", "headerTimeout", "timeout", "transport"] as const
+const PROVIDER_ONLY_KEYS = ["chunkTimeout", "headerTimeout", "timeout", "transport"] as const
 
 export function nativeSettings(settings: Settings): Settings {
   return Struct.omit(settings, CORE_KEYS)
@@ -145,6 +145,25 @@ export function modelSettings(settings: Settings | undefined) {
   return settings && Struct.omit(settings, PROVIDER_ONLY_KEYS)
 }
 
+const decodeTimeout = Schema.decodeUnknownOption(HttpTimeout)
+
+/** Applied to `headerTimeout` and `chunkTimeout` when provider settings leave them unset or invalid. */
+export const DEFAULT_TIMEOUT_MS = 300_000
+
+/** One timeout setting without a default; invalid values are dropped. */
+export function timeout(value: unknown) {
+  return Option.getOrUndefined(decodeTimeout(value))
+}
+
+/** Request timeouts from provider settings, resolved for every route. `timeout` has no default. */
+export function timeouts(settings: Readonly<Record<string, unknown>>) {
+  return {
+    timeout: timeout(settings.timeout),
+    headerTimeout: timeout(settings.headerTimeout) ?? DEFAULT_TIMEOUT_MS,
+    chunkTimeout: timeout(settings.chunkTimeout) ?? DEFAULT_TIMEOUT_MS,
+  }
+}
+
 export function mergeOverlay(
   base: Readonly<Record<string, unknown>> | undefined,
   overlay: Readonly<Record<string, unknown>> | undefined,
diff --git a/packages/core/src/session/model-request.ts b/packages/core/src/session/model-request.ts
index 26cecde25d0..cf6d4ac4dfa 100644
--- a/packages/core/src/session/model-request.ts
+++ b/packages/core/src/session/model-request.ts
@@ -310,9 +310,8 @@ export const layer = Layer.effect(
       const request = LLMRequest.update(base, {
         model: route === base.model.route ? base.model : LanguageModel.update(base.model, { route }),
         http: new HttpOptions({
-          body: base.http?.body,
+          ...base.http,
           headers: Object.keys(modelHook.headers).length === 0 ? undefined : modelHook.headers,
-          query: base.http?.query,
         }),
       })
       // History selects native windows against the catalog route before hooks run. A newly installed
diff --git a/packages/core/src/session/model-transport.ts b/packages/core/src/session/model-transport.ts
index 638ef66af4d..b42b07dc9c2 100644
--- a/packages/core/src/session/model-transport.ts
+++ b/packages/core/src/session/model-transport.ts
@@ -12,7 +12,7 @@ import {
 } from "@opencode/ai/route"
 import { AIError, AIErrorReason, TransportError, type TransportOperation } from "@opencode/ai"
 import { Hash } from "@opencode/util/hash"
-import { Cause, Clock, Context, Effect, Fiber, Layer, Metric, Queue, Scope, Semaphore, Stream } from "effect"
+import { Cause, Clock, Context, Duration, Effect, Fiber, Layer, Metric, Queue, Scope, Semaphore, Stream } from "effect"
 import { Headers } from "effect/unstable/http"
 import { Socket } from "effect/unstable/socket"
 import { makeGlobalNode } from "@opencode/util/effect/app-node"
@@ -76,7 +76,7 @@ export interface Interface {
   readonly bind: (
     sessionID: SessionSchema.ID,
     interceptor?: Interceptor,
-    idleTimeout?: number,
+    idleTimeout?: number | false,
   ) => WebSocketChannelExecutor
   readonly close: (sessionID: SessionSchema.ID) => Effect.Effect<void>
   readonly closeAll: Effect.Effect<void>
@@ -296,7 +296,7 @@ export const makeLayer = (connector: WebSocketConnector) =>
         owner: State,
         input: WebSocketChannelExchange,
         interceptor?: Interceptor,
-        idleTimeout?: number,
+        idleTimeout?: number | false,
       ) {
         if (owner.closed)
           return yield* transportError("Session WebSocket owner is closed", {
@@ -415,7 +415,7 @@ export const makeLayer = (connector: WebSocketConnector) =>
         const token = {}
         const frames = Stream.fromQueue(active.queue).pipe(
           Stream.timeoutOrElse({
-            duration: idleTimeout ?? IDLE_TIMEOUT,
+            duration: idleTimeout === false ? Duration.infinity : (idleTimeout ?? IDLE_TIMEOUT),
             orElse: () =>
               Stream.fail(
                 transportError("Timed out waiting for WebSocket data", {
@@ -509,7 +509,7 @@ export const makeLayer = (connector: WebSocketConnector) =>
       const bind = (
         sessionID: SessionSchema.ID,
         interceptor?: Interceptor,
-        idleTimeout?: number,
+        idleTimeout?: number | false,
       ): WebSocketChannelExecutor => ({
         execute: (exchange) => {
           const owner = state(sessionID)
diff --git a/packages/core/src/session/runner/retry.ts b/packages/core/src/session/runner/retry.ts
index 4885306176e..303201638ad 100644
--- a/packages/core/src/session/runner/retry.ts
+++ b/packages/core/src/session/runner/retry.ts
@@ -55,10 +55,17 @@ const schedule = Schedule.max([
   }),
 )
 
+// A timed-out attempt already waited minutes before failing, so the general allowance would let a
+// dead provider hold a step for most of an hour. Cap those attempts well below it.
+const MAX_TIMEOUT_RETRIES = 3
+
+const isTimeout = (error: AIError) => error.reason._tag === "Transport" && error.reason.code === "Timeout"
+
 export const policy = (sessionID: SessionSchema.ID) =>
   Effect.gen(function* () {
     const step = yield* Schedule.toStep(schedule)
     let attempt = 1
+    let timeouts = 0
     return (input: Input) =>
       Effect.gen(function* () {
         const now = yield* Clock.currentTimeMillis
@@ -66,6 +73,7 @@ export const policy = (sessionID: SessionSchema.ID) =>
         if (!next) return { retry: false as const }
         const [, duration] = next
         attempt++
+        if (isTimeout(input.cause)) timeouts++
         const delay = Math.ceil(Duration.toMillis(duration))
         const event: PluginHooks.Domains["session"]["retry"] = {
           sessionID,
@@ -73,7 +81,7 @@ export const policy = (sessionID: SessionSchema.ID) =>
           model: input.model,
           error: input.error,
           attempt,
-          decision: input.retry ? { retry: true, delay } : { retry: false },
+          decision: input.retry && timeouts <= MAX_TIMEOUT_RETRIES ? { retry: true, delay } : { retry: false },
         }
         yield* input.hook(event)
         if (!event.decision.retry) return event.decision
diff --git a/packages/core/test/aisdk.test.ts b/packages/core/test/aisdk.test.ts
index f4a2a2cceaf..b88a8eaaf25 100644
--- a/packages/core/test/aisdk.test.ts
+++ b/packages/core/test/aisdk.test.ts
@@ -779,6 +779,45 @@ it.effect("sends AI SDK requests directly when no HTTP hook middleware is attach
   }),
 )
 
+it.effect("fails with a retryable transport error when response headers time out", () =>
+  Effect.gen(function* () {
+    const aisdk = yield* AISDK.Service
+    const customFetch = Object.assign(
+      (_input: Parameters<typeof fetch>[0], init?: RequestInit) =>
+        new Promise<Response>((_, reject) => {
+          init?.signal?.addEventListener("abort", () => reject(init.signal?.reason), { once: true })
+        }),
+      { preconnect: fetch.preconnect },
+    )
+    yield* aisdk.hook.sdk((event) => {
+      event.sdk = createOpenAICompatible({
+        ...event.options,
+        name: String(event.options.name),
+        baseURL: String(event.options.baseURL),
+      })
+    })
+    const resolved = yield* aisdk.model(
+      model("@ai-sdk/openai-compatible", {
+        apiKey: "test",
+        baseURL: "https://example.test/v1",
+        headerTimeout: 25,
+        fetch: customFetch,
+      }),
+    )
+    const error = yield* LLMClient.generate(LLM.request({ model: resolved, prompt: "Hello" })).pipe(
+      Effect.provide(client),
+      Effect.flip,
+    )
+
+    expect(error.reason).toMatchObject({
+      _tag: "Transport",
+      operation: "request",
+      message: "Response headers timed out",
+    })
+    expect(SessionRunnerRetry.isRetryable(error)).toBeTrue()
+  }),
+)
+
 it.effect("emits malformed AI SDK tool input without executing it", () =>
   Effect.gen(function* () {
     const aisdk = yield* AISDK.Service
diff --git a/packages/core/test/session-model-transport.test.ts b/packages/core/test/session-model-transport.test.ts
index e38c3fda60e..929079e7b3e 100644
--- a/packages/core/test/session-model-transport.test.ts
+++ b/packages/core/test/session-model-transport.test.ts
@@ -634,6 +634,36 @@ describe("SessionModelTransport", () => {
     )
   })
 
+  test("disables the idle timeout when chunkTimeout is false", async () => {
+    const started = Deferred.makeUnsafe<void>()
+    const messages = queue<string | Uint8Array, AIError>()
+    const connector: WebSocketConnector = {
+      open: () =>
+        Effect.succeed({
+          sendText: () => Deferred.succeed(started, undefined),
+          messages: Stream.fromQueue(messages),
+          close: Queue.shutdown(messages),
+        }),
+    }
+
+    await runWithTestClock(
+      connector,
+      Effect.gen(function* () {
+        const transport = yield* SessionModelTransport.Service
+        const running = yield* collect(transport.bind(session, undefined, false), exchange("patient")).pipe(
+          Effect.forkChild({ startImmediately: true }),
+        )
+        yield* Deferred.await(started)
+        yield* Effect.yieldNow
+
+        yield* TestClock.adjust("2 hours")
+        yield* Queue.offer(messages, "completed:patient")
+
+        expect(yield* Fiber.join(running)).toEqual(["completed:patient"])
+      }),
+    )
+  })
+
   test("closes a newly opened connection when request creation is interrupted", async () => {
     const opened = Deferred.makeUnsafe<void>()
     const messages = queue<string | Uint8Array, AIError>()
diff --git a/packages/core/test/session-runner-retry.test.ts b/packages/core/test/session-runner-retry.test.ts
new file mode 100644
index 00000000000..fa549e8246a
--- /dev/null
+++ b/packages/core/test/session-runner-retry.test.ts
@@ -0,0 +1,47 @@
+import { describe, expect } from "bun:test"
+import { AIError, ProviderInternalError, TransportError } from "@opencode/ai"
+import { Agent } from "@opencode/schema/agent"
+import { Model } from "@opencode/schema/model"
+import { Provider } from "@opencode/core/provider"
+import { SessionSchema } from "@opencode/core/session/schema"
+import { SessionRunnerRetry } from "@opencode/core/session/runner/retry"
+import { toSessionError } from "@opencode/core/session/to-session-error"
+import { Effect } from "effect"
+import { it } from "./lib/effect"
+
+const timeout = new AIError({
+  reason: new TransportError({ message: "Timed out", transport: "http", operation: "request", code: "Timeout" }),
+})
+const internal = new AIError({ reason: new ProviderInternalError({ message: "internal" }) })
+
+const input = (cause: AIError) => ({
+  cause,
+  error: toSessionError(cause),
+  agent: Agent.ID.make("build"),
+  model: Model.Ref.make({ id: Model.ID.make("model"), providerID: Provider.ID.make("provider") }),
+  hook: () => Effect.void,
+  retry: SessionRunnerRetry.isRetryable(cause),
+})
+
+// Decisions for `count` consecutive failures of the same cause within one step.
+const decisions = (cause: AIError, count: number) =>
+  Effect.gen(function* () {
+    const policy = yield* SessionRunnerRetry.policy(SessionSchema.ID.make("ses_retry"))
+    const results: boolean[] = []
+    for (let i = 0; i < count; i++) results.push((yield* policy(input(cause))).retry)
+    return results
+  })
+
+describe("SessionRunnerRetry.policy", () => {
+  it.effect("stops retrying transport timeouts after three attempts", () =>
+    Effect.gen(function* () {
+      expect(yield* decisions(timeout, 4)).toEqual([true, true, true, false])
+    }),
+  )
+
+  it.effect("keeps the general allowance for other transient failures", () =>
+    Effect.gen(function* () {
+      expect(yield* decisions(internal, 10)).toEqual(Array(10).fill(true))
+    }),
+  )
+})
diff --git a/packages/schema/src/config/provider.ts b/packages/schema/src/config/provider.ts
index 1ae813582f5..f110da3513c 100644
--- a/packages/schema/src/config/provider.ts
+++ b/packages/schema/src/config/provider.ts
@@ -9,7 +9,8 @@ import { optional } from "../schema.js"
 export const Settings = Schema.StructWithRest(
   Schema.Struct({
     timeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
-    chunkTimeout: Schema.Finite.pipe(optional),
+    headerTimeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
+    chunkTimeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
     compaction: Provider.Compaction.pipe(optional),
     transport: Provider.Transport.pipe(optional),
   }),
diff --git a/packages/schema/src/provider.ts b/packages/schema/src/provider.ts
index a8493801d9b..9e5ced38765 100644
--- a/packages/schema/src/provider.ts
+++ b/packages/schema/src/provider.ts
@@ -47,7 +47,8 @@ export type Transport = typeof Transport.Type
 export const Settings = Schema.StructWithRest(
   Schema.Struct({
     timeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
-    chunkTimeout: Schema.Finite.pipe(optional),
+    headerTimeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
+    chunkTimeout: Schema.Union([Schema.Finite, Schema.Literal(false)]).pipe(optional),
     compaction: Compaction.pipe(optional),
     transport: Transport.pipe(optional),
   }),
diff --git a/packages/schema/test/config.test.ts b/packages/schema/test/config.test.ts
index 37c1ecfac0c..7f0f8a61fed 100644
--- a/packages/schema/test/config.test.ts
+++ b/packages/schema/test/config.test.ts
@@ -27,6 +27,23 @@ describe("Config.Entry", () => {
     expect(() => Schema.decodeUnknownSync(Config.Info)({ providers: { custom: { canonical: 1 } } })).toThrow()
   })
 
+  test("round-trips disabled and numeric provider HTTP timeouts", () => {
+    const input = {
+      providers: { custom: { settings: { timeout: 900_000, headerTimeout: 600_000, chunkTimeout: false } } },
+    } as const
+    const decoded = Schema.decodeUnknownSync(Config.Info)(input)
+    expect(Schema.encodeSync(Config.Info)(decoded)).toEqual(input)
+    expect(Schema.decodeUnknownSync(Provider.Settings)(decoded.providers?.custom?.settings)).toMatchObject({
+      timeout: 900_000,
+      headerTimeout: 600_000,
+      chunkTimeout: false,
+    })
+    expect(Schema.decodeUnknownSync(Provider.Settings)({ headerTimeout: false, chunkTimeout: 600_000 })).toMatchObject({
+      headerTimeout: false,
+      chunkTimeout: 600_000,
+    })
+  })
+
   test("accepts disabled, fixed, and random web search selection", () => {
     const decode = Schema.decodeUnknownSync(Config.Info)
 
diff --git a/services/www/src/docs/content/providers.mdx b/services/www/src/docs/content/providers.mdx
index c6ea1b20ea1..ed6797b3438 100644
--- a/services/www/src/docs/content/providers.mdx
+++ b/services/www/src/docs/content/providers.mdx
@@ -131,6 +131,31 @@ Both fields can also be set on a model or variant when only part of a provider's
 }
 ```
 
+## Timeouts
+
+HTTP requests wait up to five minutes for response headers and up to five minutes between streamed response chunks.
+Set the provider's `settings.headerTimeout` or `settings.chunkTimeout` to a number of milliseconds to change a limit,
+or to `false` to disable it. `settings.timeout` additionally bounds the whole request from send until the response
+completes; it has no default. These configuration settings apply provider-wide, not per model or variant. On a
+WebSocket transport, `chunkTimeout` bounds the gap between frames instead and defaults to thirty minutes.
+
+```jsonc title="opencode.jsonc"
+{
+  "$schema": "https://opencode.ai/config.json",
+  "providers": {
+    "anthropic": {
+      "settings": {
+        "headerTimeout": 600000,
+        "chunkTimeout": false,
+      },
+    },
+  },
+}
+```
+
+A request that exceeds either limit fails with a transport error. OpenCode retries a timed-out request up to three
+times before giving up.
+
 ## Packages
 
 The `package` field selects the runtime that communicates with a provider. Use the compatible runtime for APIs that