feat(core): add pluggable web search - #35558

import { Plugin } from "@opencode-ai/plugin/v2/effect"
import { Effect, Schema, Scope } from "effect"
import { HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"

const BraveResponse = Schema.Struct({
  web: Schema.optional(
    Schema.Struct({
      results: Schema.Array(
        Schema.Struct({
          title: Schema.String,
          url: Schema.String,
          description: Schema.optional(Schema.String),
        }),
      ),
    }),
  ),
})

export default Plugin.define<HttpClient.HttpClient | Scope.Scope>({
  id: "brave-search",
  effect: Effect.fn("BraveSearch.Plugin")(function* (ctx) {
    const http = HttpClient.filterStatusOk(yield* HttpClient.HttpClient)

    yield* ctx.integration.register({
      id: "brave",
      name: "Brave Search",
      methods: [
        { type: "key", label: "API key" },
        { type: "env", names: ["BRAVE_SEARCH_API_KEY"] },
      ],
    })

    yield* ctx.websearch.register({
      id: "brave",
      name: "Brave Search",
      execute: (input) =>
        Effect.gen(function* () {
          const connection = yield* ctx.integration.connection.active("brave")
          const credential = connection ? yield* ctx.integration.connection.resolve(connection) : undefined
          if (credential?.type !== "key") return yield* Effect.fail(new Error("Missing Brave API key"))

          const url = new URL("https://api.search.brave.com/res/v1/web/search")
          url.searchParams.set("q", input.query)
          url.searchParams.set("count", "8")

          const response = yield* HttpClientRequest.get(url.toString()).pipe(
            HttpClientRequest.acceptJson,
            HttpClientRequest.setHeader("X-Subscription-Token", credential.key),
            http.execute,
            Effect.flatMap(HttpClientResponse.schemaBodyJson(BraveResponse)),
          )
          const results = response.web?.results ?? []
          return {
            text: results
              .map((result) => `## [${result.title}](${result.url})${result.description ? `\n${result.description}` : ""}`)
              .join("\n\n"),
            metadata: response,
          }
        }),
    })
  }),
})