opencode/packages/core/src/tool/plugin/websearch.ts

export * as WebSearchTool from "./websearch"

import type { Context as PluginContext } from "@opencode-ai/plugin/effect/plugin"
import { ToolFailure } from "@opencode-ai/ai"
import { Effect, Schema, Semaphore } from "effect"
import { Form } from "../../form"
import { KV } from "../../kv"
import { Permission } from "../../permission"
import { WebSearch } from "../../websearch"

export const name = "websearch"
export const NO_RESULTS = "No search results found. Please try a different query."
const providerSelectionLock = Semaphore.makeUnsafe(1)

export const description = `Search the web using the user's selected search integration. Use this for current information beyond knowledge cutoff.

The current year is ${new Date().getFullYear()}. Use this year when searching for recent information or current events.`

export const Input = Schema.Struct({
  query: Schema.String.annotate({ description: "Websearch query" }),
})

const Output = Schema.Struct({
  provider: WebSearch.ID,
  results: Schema.Array(WebSearch.Result),
})
export const Plugin = {
  id: "opencode.tool.websearch",
  effect: Effect.fn("WebSearchTool.Plugin")(function* (ctx: PluginContext) {
    const permission = yield* Permission.Service
    const forms = yield* Form.Service
    const kv = yield* KV.Service
    const websearch = yield* WebSearch.Service

    yield* ctx.tool
      .transform((draft) =>
        draft.add({
          name,
          options: { codemode: false },
          description,
          input: Input,
          output: Output,
          execute: (input, context) =>
            Effect.gen(function* () {
              yield* permission.assert({
                action: name,
                resources: [input.query],
                save: ["*"],
                metadata: input,
                sessionID: context.sessionID,
                agent: context.agent,
                source: { type: "tool", messageID: context.messageID, id: context.id },
              })
              const search = (): Effect.Effect<Effect.Success<ReturnType<typeof ctx.websearch.query>>, unknown> =>
                ctx.websearch.query(input).pipe(
                  Effect.catch((error) => {
                    if (!Schema.is(WebSearch.ProviderRequiredError)(error)) return Effect.fail(error)
                    return providerSelectionLock
                      .withPermit(
                        Effect.gen(function* () {
                          if (yield* websearch.default()) return yield* Effect.void
                          const providers = (yield* ctx.websearch.providers()).data
                          const defaultProvider = providers[0]
                          if (!defaultProvider) return yield* new WebSearch.ProviderRequiredError()
                          const response = yield* forms.ask({
                            sessionID: context.sessionID,
                            title: "Web Search",
                            metadata: { kind: "websearch.provider" },
                            fields: [
                              {
                                key: "choice",
                                description: "Allow OpenCode to search the web for up-to-date information?",
                                type: "string",
                                required: true,
                                custom: false,
                                options: [
                                  {
                                    value: "allow",
                                    label: `Allow web search via ${defaultProvider.name}`,
                                  },
                                  {
                                    value: "choose",
                                    label: "Choose another provider",
                                  },
                                  { value: "disable", label: "Disable web search" },
                                ],
                              },
                            ],
                          })
                          if (response.status === "cancelled")
                            return yield* Effect.fail(new Error("Web search cancelled"))
                          if (response.answer.choice === "disable") {
                            yield* kv.set("websearch:provider", false)
                            return yield* new WebSearch.DisabledError()
                          }
                          const selection =
                            response.answer.choice === "choose"
                              ? yield* forms.ask({
                                  sessionID: context.sessionID,
                                  title: "Choose a web search provider",
                                  metadata: { kind: "websearch.provider" },
                                  fields: [
                                    {
                                      key: "provider",
                                      description: "Choose a provider for web search.",
                                      type: "string",
                                      required: true,
                                      custom: false,
                                      options: providers.map((provider) => ({
                                        value: provider.id,
                                        label: provider.name,
                                      })),
                                    },
                                  ],
                                })
                              : undefined
                          if (selection?.status === "cancelled")
                            return yield* Effect.fail(new Error("Web search cancelled"))
                          const providerID = selection?.answer.provider ?? defaultProvider.id
                          if (
                            typeof providerID !== "string" ||
                            !providers.some((provider) => provider.id === providerID)
                          )
                            return yield* new WebSearch.ProviderRequiredError()
                          return yield* kv.set("websearch:provider", providerID)
                        }),
                      )
                      .pipe(
                        Effect.timeoutOrElse({
                          duration: "1 minute",
                          orElse: () => Effect.fail(new Error("Web search cancelled")),
                        }),
                        Effect.andThen(Effect.suspend(search)),
                      )
                  }),
                )
              const result = yield* search()
              const output = {
                provider: result.data.providerID,
                results: result.data.results,
              }
              const content = output.results.length
                ? output.results
                    .map((result) => {
                      const title = result.title ?? result.url
                      const published = result.time.published
                        ? `\nPublished: ${new Date(result.time.published).toISOString()}`
                        : ""
                      return `## [${title}](${result.url})${published}${result.content ? `\n\n${result.content}` : ""}`
                    })
                    .join("\n\n")
                : NO_RESULTS
              return { output, content, metadata: { provider: output.provider } }
            }).pipe(
              Effect.mapError(
                (error) => new ToolFailure({ message: `Unable to search the web for ${input.query}`, error }),
              ),
            ),
        }),
      )
      .pipe(Effect.orDie)

    yield* ctx.session.hook("context", (event) =>
      Effect.gen(function* () {
        if ((yield* kv.get("websearch:provider")) === false) delete event.tools[name]
      }),
    )
  }),
}