feat(websearch): add parallel provider rollout (#26227)

packages/opencode/src/tool/mcp-websearch.ts

@@ -1,9 +1,10 @@
 import { Duration, Effect, Schema } from "effect"
 import { HttpClient, HttpClientRequest } from "effect/unstable/http"
 
-const URL = process.env.EXA_API_KEY
+export const EXA_URL = process.env.EXA_API_KEY
   ? `https://mcp.exa.ai/mcp?exaApiKey=${encodeURIComponent(process.env.EXA_API_KEY)}`
   : "https://mcp.exa.ai/mcp"
+export const PARALLEL_URL = "https://search.parallel.ai/mcp"
 
 const McpResult = Schema.Struct({
   result: Schema.Struct({
@@ -18,11 +19,23 @@ const McpResult = Schema.Struct({
 
 const decode = Schema.decodeUnknownEffect(Schema.fromJsonString(McpResult))
 
-const parseSse = Effect.fn("McpExa.parseSse")(function* (body: string) {
+const parsePayload = (payload: string) =>
+  Effect.gen(function* () {
+    const trimmed = payload.trim()
+    if (!trimmed.startsWith("{")) return undefined
+    const data = yield* decode(trimmed)
+    return data.result.content.find((item) => item.text)?.text
+  })
+
+export const parseResponse = Effect.fn("McpWebSearch.parseResponse")(function* (body: string) {
+  const trimmed = body.trim()
+  const direct = trimmed ? yield* parsePayload(trimmed) : undefined
+  if (direct) return direct
+
   for (const line of body.split("\n")) {
     if (!line.startsWith("data: ")) continue
-    const data = yield* decode(line.substring(6))
-    if (data.result.content[0]?.text) return data.result.content[0].text
+    const data = yield* parsePayload(line.substring(6))
+    if (data) return data
   }
   return undefined
 })
@@ -35,6 +48,13 @@ export const SearchArgs = Schema.Struct({
   contextMaxCharacters: Schema.optional(Schema.Number),
 })
 
+export const ParallelSearchArgs = Schema.Struct({
+  objective: Schema.String,
+  search_queries: Schema.Array(Schema.String),
+  session_id: Schema.optional(Schema.String),
+  model_name: Schema.optional(Schema.String),
+})
+
 const McpRequest = <F extends Schema.Struct.Fields>(args: Schema.Struct<F>) =>
   Schema.Struct({
     jsonrpc: Schema.Literal("2.0"),
@@ -48,14 +68,17 @@ const McpRequest = <F extends Schema.Struct.Fields>(args: Schema.Struct<F>) =>
 
 export const call = <F extends Schema.Struct.Fields>(
   http: HttpClient.HttpClient,
+  url: string,
   tool: string,
   args: Schema.Struct<F>,
   value: Schema.Struct.Type<F>,
   timeout: Duration.Input,
+  headers?: Record<string, string>,
 ) =>
   Effect.gen(function* () {
-    const request = yield* HttpClientRequest.post(URL).pipe(
+    const request = yield* HttpClientRequest.post(url).pipe(
       HttpClientRequest.accept("application/json, text/event-stream"),
+      HttpClientRequest.setHeaders(headers ?? {}),
       HttpClientRequest.schemaBodyJson(McpRequest(args))({
         jsonrpc: "2.0" as const,
         id: 1 as const,
@@ -69,5 +92,5 @@ export const call = <F extends Schema.Struct.Fields>(
         Effect.timeoutOrElse({ duration: timeout, orElse: () => Effect.die(new Error(`${tool} request timed out`)) }),
       )
     const body = yield* response.text
-    return yield* parseSse(body)
+    return yield* parseResponse(body)
   })

packages/opencode/src/tool/registry.ts

@@ -49,6 +49,13 @@ import { Permission } from "@/permission"
 
 const log = Log.create({ service: "tool.registry" })
 
+export function webSearchEnabled(
+  providerID: ProviderID,
+  flags = { exa: Flag.OPENCODE_ENABLE_EXA, parallel: Flag.OPENCODE_ENABLE_PARALLEL },
+) {
+  return providerID === ProviderID.opencode || flags.exa || flags.parallel
+}
+
 type TaskDef = Tool.InferDef<typeof TaskTool>
 type ReadDef = Tool.InferDef<typeof ReadTool>
 
@@ -284,7 +291,7 @@ export const layer: Layer.Layer<
     const tools: Interface["tools"] = Effect.fn("ToolRegistry.tools")(function* (input) {
       const filtered = (yield* all()).filter((tool) => {
         if (tool.id === WebSearchTool.id) {
-          return input.providerID === ProviderID.opencode || Flag.OPENCODE_ENABLE_EXA
+          return webSearchEnabled(input.providerID)
         }
 
         const usePatch =

packages/opencode/src/tool/websearch.ts

@@ -1,8 +1,11 @@
 import { Effect, Schema } from "effect"
 import { HttpClient } from "effect/unstable/http"
 import * as Tool from "./tool"
-import * as McpExa from "./mcp-exa"
+import * as McpWebSearch from "./mcp-websearch"
 import DESCRIPTION from "./websearch.txt"
+import { Flag } from "@opencode-ai/core/flag/flag"
+import { checksum } from "@opencode-ai/core/util/encode"
+import { InstallationVersion } from "@opencode-ai/core/installation/version"
 
 export const Parameters = Schema.Struct({
   query: Schema.String.annotate({ description: "Websearch query" }),
@@ -21,6 +24,81 @@ export const Parameters = Schema.Struct({
   }),
 })
 
+const WebSearchProviderSchema = Schema.Literals(["exa", "parallel"])
+export type WebSearchProvider = Schema.Schema.Type<typeof WebSearchProviderSchema>
+
+export function selectWebSearchProvider(
+  sessionID: string,
+  flags = { exa: Flag.OPENCODE_ENABLE_EXA, parallel: Flag.OPENCODE_ENABLE_PARALLEL },
+): WebSearchProvider {
+  const override = process.env.OPENCODE_WEBSEARCH_PROVIDER
+  if (override === "exa" || override === "parallel") return override
+  if (flags.parallel) return "parallel"
+  if (flags.exa) return "exa"
+
+  return Number.parseInt(checksum(sessionID) ?? "0", 36) % 2 === 0 ? "exa" : "parallel"
+}
+
+export function webSearchProviderLabel(provider: unknown) {
+  if (provider === "parallel") return "Parallel Web Search"
+  if (provider === "exa") return "Exa Web Search"
+  return "Web Search"
+}
+
+export function webSearchModelName(extra: Tool.Context["extra"]) {
+  const model = extra?.model
+  if (!model || typeof model !== "object") return undefined
+  const api = "api" in model && model.api && typeof model.api === "object" ? model.api : undefined
+  const apiID = api && "id" in api && typeof api.id === "string" ? api.id : undefined
+  const id = "id" in model && typeof model.id === "string" ? model.id : undefined
+  return (apiID ?? id)?.slice(0, 100)
+}
+
+function parallelAuthHeaders() {
+  const headers = { "User-Agent": `opencode/${InstallationVersion}` }
+  if (!process.env.PARALLEL_API_KEY) return headers
+  return { ...headers, Authorization: `Bearer ${process.env.PARALLEL_API_KEY}` }
+}
+
+function callProvider(
+  http: HttpClient.HttpClient,
+  provider: WebSearchProvider,
+  params: Schema.Schema.Type<typeof Parameters>,
+  ctx: Tool.Context,
+) {
+  if (provider === "parallel") {
+    return McpWebSearch.call(
+      http,
+      McpWebSearch.PARALLEL_URL,
+      "web_search",
+      McpWebSearch.ParallelSearchArgs,
+      {
+        objective: params.query,
+        search_queries: [params.query],
+        session_id: ctx.sessionID,
+        model_name: webSearchModelName(ctx.extra),
+      },
+      "25 seconds",
+      parallelAuthHeaders(),
+    )
+  }
+
+  return McpWebSearch.call(
+    http,
+    McpWebSearch.EXA_URL,
+    "web_search_exa",
+    McpWebSearch.SearchArgs,
+    {
+      query: params.query,
+      type: params.type || "auto",
+      numResults: params.numResults || 8,
+      livecrawl: params.livecrawl || "fallback",
+      contextMaxCharacters: params.contextMaxCharacters,
+    },
+    "25 seconds",
+  )
+}
+
 export const WebSearchTool = Tool.define(
   "websearch",
   Effect.gen(function* () {
@@ -33,6 +111,10 @@ export const WebSearchTool = Tool.define(
       parameters: Parameters,
       execute: (params: Schema.Schema.Type<typeof Parameters>, ctx: Tool.Context) =>
         Effect.gen(function* () {
+          const provider = selectWebSearchProvider(ctx.sessionID)
+          const title = webSearchProviderLabel(provider)
+          yield* ctx.metadata({ title: `${title} "${params.query}"`, metadata: { provider } })
+
           yield* ctx.ask({
             permission: "websearch",
             patterns: [params.query],
@@ -43,27 +125,16 @@ export const WebSearchTool = Tool.define(
               livecrawl: params.livecrawl,
               type: params.type,
               contextMaxCharacters: params.contextMaxCharacters,
+              provider,
             },
           })
 
-          const result = yield* McpExa.call(
-            http,
-            "web_search_exa",
-            McpExa.SearchArgs,
-            {
-              query: params.query,
-              type: params.type || "auto",
-              numResults: params.numResults || 8,
-              livecrawl: params.livecrawl || "fallback",
-              contextMaxCharacters: params.contextMaxCharacters,
-            },
-            "25 seconds",
-          )
+          const result = yield* callProvider(http, provider, params, ctx)
 
           return {
             output: result ?? "No search results found. Please try a different query.",
-            title: `Web search: ${params.query}`,
-            metadata: {},
+            title: `${title}: ${params.query}`,
+            metadata: { provider },
           }
         }).pipe(Effect.orDie),
     }

packages/opencode/src/tool/websearch.txt

@@ -1,12 +1,12 @@
-- Search the web using Exa AI - performs real-time web searches and can scrape content from specific URLs
+- Search the web using the session's web search provider - performs real-time web searches and can scrape content from specific URLs
 - Provides up-to-date information for current events and recent data
 - Supports configurable result counts and returns the content from the most relevant websites
 - Use this tool for accessing information beyond knowledge cutoff
 - Searches are performed automatically within a single API call
 
 Usage notes:
-  - Supports live crawling modes: 'fallback' (backup if cached unavailable) or 'preferred' (prioritize live crawling)
-  - Search types: 'auto' (balanced), 'fast' (quick results), 'deep' (comprehensive search)
+  - Supports live crawling modes when available: 'fallback' (backup if cached unavailable) or 'preferred' (prioritize live crawling)
+  - Search types when available: 'auto' (balanced), 'fast' (quick results), 'deep' (comprehensive search)
   - Configurable context length for optimal LLM integration
   - Domain filtering and advanced search options available