# Web Search Tools Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Add modular `web_search` and `web_fetch` pi tools backed by Exa, with runtime config loaded from `~/.pi/agent/web-search.json` and an internal provider adapter layer for future providers.

**Architecture:** Build a package-style extension in `.pi/agent/extensions/web-search/` so it can carry `exa-js` and local tests cleanly. Keep config parsing, Exa request mapping, and output formatting in pure modules covered by `node:test` via `tsx`, then layer pi-specific tool registration and renderers on top.

**Tech Stack:** Pi extensions API, `exa-js`, `@sinclair/typebox`, `@mariozechner/pi-coding-agent`, `@mariozechner/pi-tui`, Node `node:test`, `tsx`, TypeScript

---

## File Structure

- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/package.json`
  - Local extension package manifest, npm scripts, and dependencies.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/index.ts`
  - Extension entrypoint that registers `web_search` and `web_fetch`.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/schema.ts`
  - TypeBox schemas for config and tool parameter validation.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.ts`
  - Loads and validates `~/.pi/agent/web-search.json`, normalizes the provider list, and resolves the default provider.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.test.ts`
  - Tests config parsing, normalization, and helpful error messages.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/types.ts`
  - Provider-agnostic request/response interfaces used by both tools.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.ts`
  - Exa-backed implementation of the provider interface.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.test.ts`
  - Tests generic request → Exa call mapping and per-URL fetch failure handling.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.ts`
  - Shared compact text formatting and truncation helpers.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.test.ts`
  - Tests metadata-only search formatting, text truncation, and batch failure formatting.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.ts`
  - `web_search` tool factory, execute path, and tool renderers.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.test.ts`
  - Tests non-empty query validation and happy-path execution with a fake provider.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.ts`
  - `web_fetch` tool factory, input normalization, execute path, and tool renderers.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.test.ts`
  - Tests URL normalization, default text mode, and invalid URL rejection.
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/extension.test.ts`
  - Smoke test that the extension entrypoint registers both tool names.
- Modify: `/home/alex/dotfiles/docs/superpowers/plans/2026-04-09-web-search-tools.md`
  - Check boxes as work progresses.

## Environment Notes

- `/home/alex/.pi/agent/extensions` resolves to `/home/alex/dotfiles/.pi/agent/extensions`, so editing files in the repo updates the live global pi extension path.
- The config file for this feature lives outside the repo at `~/.pi/agent/web-search.json`.
- Use `/reload` inside pi after file edits to reload the extension.
- Run package-local tests from `/home/alex/dotfiles/.pi/agent/extensions/web-search`.

### Task 1: Scaffold the extension package and build the config loader first

**Files:**
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/package.json`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.test.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/schema.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.test.ts`

- [x] **Step 1: Create the extension package scaffold and install dependencies**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/package.json` with this content:

```json
{
  "name": "pi-web-search-extension",
  "private": true,
  "version": "0.0.0",
  "type": "module",
  "scripts": {
    "test": "tsx --test src/**/*.test.ts"
  },
  "pi": {
    "extensions": [
      "./index.ts"
    ]
  },
  "dependencies": {
    "@sinclair/typebox": "^0.34.49",
    "exa-js": "^2.11.0"
  },
  "devDependencies": {
    "@mariozechner/pi-coding-agent": "^0.66.1",
    "@mariozechner/pi-tui": "^0.66.1",
    "@types/node": "^25.5.2",
    "tsx": "^4.21.0",
    "typescript": "^6.0.2"
  }
}
```

Then run:

```bash
mkdir -p /home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers
mkdir -p /home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npm install
```

Expected: `node_modules/` is created and `npm install` exits with code `0`.

- [x] **Step 2: Write the failing config tests**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import { mkdtemp, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { loadWebSearchConfig, WebSearchConfigError } from "./config.ts";

async function writeTempConfig(contents: unknown) {
  const dir = await mkdtemp(join(tmpdir(), "pi-web-search-config-"));
  const file = join(dir, "web-search.json");
  const body = typeof contents === "string" ? contents : JSON.stringify(contents, null, 2);
  await writeFile(file, body, "utf8");
  return file;
}

test("loadWebSearchConfig returns a normalized default provider and provider lookup", async () => {
  const file = await writeTempConfig({
    defaultProvider: "exa-main",
    providers: [
      {
        name: "exa-main",
        type: "exa",
        apiKey: "exa-test-key",
        options: {
          defaultSearchLimit: 7,
          defaultFetchTextMaxCharacters: 9000
        }
      }
    ]
  });

  const config = await loadWebSearchConfig(file);

  assert.equal(config.defaultProviderName, "exa-main");
  assert.equal(config.defaultProvider.name, "exa-main");
  assert.equal(config.providersByName.get("exa-main")?.apiKey, "exa-test-key");
  assert.equal(config.providers[0]?.options?.defaultSearchLimit, 7);
});

test("loadWebSearchConfig rejects a missing default provider target", async () => {
  const file = await writeTempConfig({
    defaultProvider: "missing",
    providers: [
      {
        name: "exa-main",
        type: "exa",
        apiKey: "exa-test-key"
      }
    ]
  });

  await assert.rejects(
    () => loadWebSearchConfig(file),
    (error) =>
      error instanceof WebSearchConfigError &&
      /defaultProvider \"missing\"/.test(error.message),
  );
});

test("loadWebSearchConfig rejects a missing file with a helpful example message", async () => {
  const file = join(tmpdir(), "pi-web-search-does-not-exist.json");

  await assert.rejects(
    () => loadWebSearchConfig(file),
    (error) =>
      error instanceof WebSearchConfigError &&
      error.message.includes(file) &&
      error.message.includes('"defaultProvider"') &&
      error.message.includes('"providers"'),
  );
});
```

- [x] **Step 3: Run the config tests to verify they fail**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/config.test.ts
```

Expected: `FAIL` with an `ERR_MODULE_NOT_FOUND` error for `./config.ts`.

- [x] **Step 4: Write the minimal schema and config loader implementation**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/schema.ts` with this content:

```ts
import { Type, type Static } from "@sinclair/typebox";

export const ProviderOptionsSchema = Type.Object({
  defaultSearchLimit: Type.Optional(Type.Integer({ minimum: 1 })),
  defaultFetchTextMaxCharacters: Type.Optional(Type.Integer({ minimum: 1 })),
  defaultFetchHighlightsMaxCharacters: Type.Optional(Type.Integer({ minimum: 1 })),
});

export const ExaProviderConfigSchema = Type.Object({
  name: Type.String({ minLength: 1 }),
  type: Type.Literal("exa"),
  apiKey: Type.String({ minLength: 1 }),
  options: Type.Optional(ProviderOptionsSchema),
});

export const WebSearchConfigSchema = Type.Object({
  defaultProvider: Type.String({ minLength: 1 }),
  providers: Type.Array(ExaProviderConfigSchema, { minItems: 1 }),
});

export const WebSearchParamsSchema = Type.Object({
  query: Type.String({ minLength: 1, description: "Search query" }),
  limit: Type.Optional(Type.Integer({ minimum: 1, maximum: 25 })),
  includeDomains: Type.Optional(Type.Array(Type.String())),
  excludeDomains: Type.Optional(Type.Array(Type.String())),
  startPublishedDate: Type.Optional(Type.String()),
  endPublishedDate: Type.Optional(Type.String()),
  category: Type.Optional(Type.String()),
  provider: Type.Optional(Type.String()),
});

export const WebFetchParamsSchema = Type.Object({
  urls: Type.Array(Type.String(), { minItems: 1 }),
  text: Type.Optional(Type.Boolean()),
  highlights: Type.Optional(Type.Boolean()),
  summary: Type.Optional(Type.Boolean()),
  textMaxCharacters: Type.Optional(Type.Integer({ minimum: 1 })),
  provider: Type.Optional(Type.String()),
});

export type ProviderOptions = Static<typeof ProviderOptionsSchema>;
export type ExaProviderConfig = Static<typeof ExaProviderConfigSchema>;
export type WebSearchConfig = Static<typeof WebSearchConfigSchema>;
export type WebSearchParams = Static<typeof WebSearchParamsSchema>;
export type WebFetchParams = Static<typeof WebFetchParamsSchema>;
```

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/config.ts` with this content:

```ts
import { readFile } from "node:fs/promises";
import { homedir } from "node:os";
import { join } from "node:path";
import { Value } from "@sinclair/typebox/value";
import { WebSearchConfigSchema, type ExaProviderConfig, type WebSearchConfig } from "./schema.ts";

export interface ResolvedWebSearchConfig {
  path: string;
  defaultProviderName: string;
  defaultProvider: ExaProviderConfig;
  providers: ExaProviderConfig[];
  providersByName: Map<string, ExaProviderConfig>;
}

export class WebSearchConfigError extends Error {
  constructor(message: string) {
    super(message);
    this.name = "WebSearchConfigError";
  }
}

export function getDefaultWebSearchConfigPath() {
  return join(homedir(), ".pi", "agent", "web-search.json");
}

function exampleConfigSnippet() {
  return JSON.stringify(
    {
      defaultProvider: "exa-main",
      providers: [
        {
          name: "exa-main",
          type: "exa",
          apiKey: "exa_..."
        }
      ]
    },
    null,
    2,
  );
}

export function normalizeWebSearchConfig(config: WebSearchConfig, path: string): ResolvedWebSearchConfig {
  const providersByName = new Map<string, ExaProviderConfig>();

  for (const provider of config.providers) {
    if (!provider.apiKey.trim()) {
      throw new WebSearchConfigError(`Provider \"${provider.name}\" in ${path} is missing a literal apiKey.`);
    }
    if (providersByName.has(provider.name)) {
      throw new WebSearchConfigError(`Duplicate provider name \"${provider.name}\" in ${path}.`);
    }
    providersByName.set(provider.name, provider);
  }

  const defaultProvider = providersByName.get(config.defaultProvider);
  if (!defaultProvider) {
    throw new WebSearchConfigError(
      `defaultProvider \"${config.defaultProvider}\" does not match any configured provider in ${path}.`,
    );
  }

  return {
    path,
    defaultProviderName: config.defaultProvider,
    defaultProvider,
    providers: [...providersByName.values()],
    providersByName,
  };
}

export async function loadWebSearchConfig(path = getDefaultWebSearchConfigPath()) {
  let raw: string;
  try {
    raw = await readFile(path, "utf8");
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === "ENOENT") {
      throw new WebSearchConfigError(
        `Missing web-search config at ${path}.\nCreate ${path} with contents like:\n${exampleConfigSnippet()}`,
      );
    }
    throw error;
  }

  let parsed: unknown;
  try {
    parsed = JSON.parse(raw);
  } catch (error) {
    throw new WebSearchConfigError(`Invalid JSON in ${path}: ${(error as Error).message}`);
  }

  if (!Value.Check(WebSearchConfigSchema, parsed)) {
    const [firstError] = [...Value.Errors(WebSearchConfigSchema, parsed)];
    throw new WebSearchConfigError(
      `Invalid web-search config at ${path}: ${firstError?.path ?? "/"} ${firstError?.message ?? "failed validation"}`,
    );
  }

  return normalizeWebSearchConfig(parsed as WebSearchConfig, path);
}
```

- [x] **Step 5: Run the config tests to verify they pass**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/config.test.ts
```

Expected: `PASS` for all three tests.

- [x] **Step 6: Commit the config layer**

Run:

```bash
git -C /home/alex/dotfiles add \
  .pi/agent/extensions/web-search/package.json \
  .pi/agent/extensions/web-search/src/schema.ts \
  .pi/agent/extensions/web-search/src/config.ts \
  .pi/agent/extensions/web-search/src/config.test.ts \
  docs/superpowers/plans/2026-04-09-web-search-tools.md

git -C /home/alex/dotfiles commit -m "test: add web search config loader"
```

### Task 2: Add the provider-agnostic types and the Exa adapter

**Files:**
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.test.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/types.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.test.ts`

- [x] **Step 1: Write the failing Exa adapter tests**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import { createExaProvider } from "./exa.ts";

const baseConfig = {
  name: "exa-main",
  type: "exa" as const,
  apiKey: "exa-test-key",
  options: {
    defaultSearchLimit: 7,
    defaultFetchTextMaxCharacters: 9000,
    defaultFetchHighlightsMaxCharacters: 1200,
  },
};

test("createExaProvider maps generic search requests to Exa search with contents disabled", async () => {
  let captured: { query: string; options: Record<string, unknown> } | undefined;

  const provider = createExaProvider(baseConfig, () => ({
    async search(query, options) {
      captured = { query, options };
      return {
        requestId: "req-search-1",
        searchTime: 123,
        results: [
          {
            id: "doc-1",
            title: "Exa Docs",
            url: "https://exa.ai/docs",
            publishedDate: "2026-04-09",
            author: "Exa",
            score: 0.98,
          },
        ],
      };
    },
    async getContents() {
      throw new Error("not used");
    },
  }));

  const result = await provider.search({
    query: "exa docs",
    includeDomains: ["exa.ai"],
  });

  assert.deepEqual(captured, {
    query: "exa docs",
    options: {
      contents: false,
      numResults: 7,
      includeDomains: ["exa.ai"],
      excludeDomains: undefined,
      startPublishedDate: undefined,
      endPublishedDate: undefined,
      category: undefined,
    },
  });
  assert.equal(result.providerName, "exa-main");
  assert.equal(result.results[0]?.url, "https://exa.ai/docs");
});

test("createExaProvider fetch defaults to text and preserves per-url failures", async () => {
  const calls: Array<{ urls: string[]; options: Record<string, unknown> }> = [];

  const provider = createExaProvider(baseConfig, () => ({
    async search() {
      throw new Error("not used");
    },
    async getContents(urls, options) {
      const requestUrls = Array.isArray(urls) ? urls : [urls];
      calls.push({ urls: requestUrls, options });

      if (requestUrls[0] === "https://bad.example") {
        throw new Error("429 rate limited");
      }

      return {
        requestId: `req-${calls.length}`,
        results: [
          {
            url: requestUrls[0],
            title: "Fetched page",
            text: "Fetched body",
          },
        ],
      };
    },
  }));

  const result = await provider.fetch({
    urls: ["https://good.example", "https://bad.example"],
  });

  assert.equal((calls[0]?.options.text as { maxCharacters: number }).maxCharacters, 9000);
  assert.deepEqual(result.results, [
    {
      url: "https://good.example",
      title: "Fetched page",
      text: "Fetched body",
      highlights: undefined,
      summary: undefined,
    },
    {
      url: "https://bad.example",
      title: null,
      error: "429 rate limited",
    },
  ]);
});
```

- [x] **Step 2: Run the Exa adapter tests to verify they fail**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/providers/exa.test.ts
```

Expected: `FAIL` with an `ERR_MODULE_NOT_FOUND` error for `./exa.ts`.

- [x] **Step 3: Write the provider interface and Exa adapter implementation**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/types.ts` with this content:

```ts
export interface NormalizedSearchRequest {
  query: string;
  limit?: number;
  includeDomains?: string[];
  excludeDomains?: string[];
  startPublishedDate?: string;
  endPublishedDate?: string;
  category?: string;
  provider?: string;
}

export interface NormalizedSearchResult {
  id?: string;
  title: string | null;
  url: string;
  publishedDate?: string;
  author?: string;
  score?: number;
}

export interface NormalizedSearchResponse {
  providerName: string;
  requestId?: string;
  searchTime?: number;
  results: NormalizedSearchResult[];
}

export interface NormalizedFetchRequest {
  urls: string[];
  text?: boolean;
  highlights?: boolean;
  summary?: boolean;
  textMaxCharacters?: number;
  provider?: string;
}

export interface NormalizedFetchResult {
  url: string;
  title: string | null;
  text?: string;
  highlights?: string[];
  summary?: string;
  error?: string;
}

export interface NormalizedFetchResponse {
  providerName: string;
  requestIds?: string[];
  results: NormalizedFetchResult[];
}

export interface WebProvider {
  name: string;
  type: string;
  search(request: NormalizedSearchRequest): Promise<NormalizedSearchResponse>;
  fetch(request: NormalizedFetchRequest): Promise<NormalizedFetchResponse>;
}
```

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/providers/exa.ts` with this content:

```ts
import Exa from "exa-js";
import type { ExaProviderConfig } from "../schema.ts";
import type {
  NormalizedFetchRequest,
  NormalizedFetchResponse,
  NormalizedSearchRequest,
  NormalizedSearchResponse,
  WebProvider,
} from "./types.ts";

export interface ExaClientLike {
  search(query: string, options?: Record<string, unknown>): Promise<any>;
  getContents(urls: string[] | string, options?: Record<string, unknown>): Promise<any>;
}

export type ExaClientFactory = (apiKey: string) => ExaClientLike;

export function buildSearchOptions(config: ExaProviderConfig, request: NormalizedSearchRequest) {
  return {
    contents: false,
    numResults: request.limit ?? config.options?.defaultSearchLimit ?? 5,
    includeDomains: request.includeDomains,
    excludeDomains: request.excludeDomains,
    startPublishedDate: request.startPublishedDate,
    endPublishedDate: request.endPublishedDate,
    category: request.category,
  };
}

export function buildFetchOptions(config: ExaProviderConfig, request: NormalizedFetchRequest) {
  const text = request.text ?? (!request.highlights && !request.summary);

  return {
    ...(text
      ? {
          text: {
            maxCharacters: request.textMaxCharacters ?? config.options?.defaultFetchTextMaxCharacters ?? 12000,
          },
        }
      : {}),
    ...(request.highlights
      ? {
          highlights: {
            maxCharacters: config.options?.defaultFetchHighlightsMaxCharacters ?? 1000,
          },
        }
      : {}),
    ...(request.summary ? { summary: true } : {}),
  };
}

export function createExaProvider(
  config: ExaProviderConfig,
  createClient: ExaClientFactory = (apiKey) => new Exa(apiKey) as unknown as ExaClientLike,
): WebProvider {
  const client = createClient(config.apiKey);

  return {
    name: config.name,
    type: config.type,

    async search(request: NormalizedSearchRequest): Promise<NormalizedSearchResponse> {
      const response = await client.search(request.query, buildSearchOptions(config, request));
      return {
        providerName: config.name,
        requestId: response.requestId,
        searchTime: response.searchTime,
        results: (response.results ?? []).map((item: any) => ({
          id: item.id,
          title: item.title ?? null,
          url: item.url,
          publishedDate: item.publishedDate,
          author: item.author,
          score: item.score,
        })),
      };
    },

    async fetch(request: NormalizedFetchRequest): Promise<NormalizedFetchResponse> {
      const requestIds: string[] = [];
      const options = buildFetchOptions(config, request);

      const results = await Promise.all(
        request.urls.map(async (url) => {
          try {
            const response = await client.getContents([url], options);
            if (response.requestId) {
              requestIds.push(response.requestId);
            }

            const item = response.results?.[0];
            if (!item) {
              return {
                url,
                title: null,
                error: "No content returned",
              };
            }

            return {
              url: item.url ?? url,
              title: item.title ?? null,
              text: typeof item.text === "string" ? item.text : undefined,
              highlights: Array.isArray(item.highlights) ? item.highlights : undefined,
              summary: typeof item.summary === "string" ? item.summary : undefined,
            };
          } catch (error) {
            return {
              url,
              title: null,
              error: (error as Error).message,
            };
          }
        }),
      );

      return {
        providerName: config.name,
        requestIds,
        results,
      };
    },
  };
}
```

- [x] **Step 4: Run the Exa adapter tests to verify they pass**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/providers/exa.test.ts
```

Expected: `PASS` for both tests.

- [x] **Step 5: Commit the provider layer**

Run:

```bash
git -C /home/alex/dotfiles add \
  .pi/agent/extensions/web-search/src/providers/types.ts \
  .pi/agent/extensions/web-search/src/providers/exa.ts \
  .pi/agent/extensions/web-search/src/providers/exa.test.ts \
  docs/superpowers/plans/2026-04-09-web-search-tools.md

git -C /home/alex/dotfiles commit -m "test: add exa web provider adapter"
```

### Task 3: Add the shared formatter and truncation helpers

**Files:**
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.test.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.test.ts`

- [x] **Step 1: Write the failing formatter tests**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import { formatFetchOutput, formatSearchOutput, truncateText } from "./format.ts";

test("formatSearchOutput renders a compact metadata-only list", () => {
  const output = formatSearchOutput({
    providerName: "exa-main",
    results: [
      {
        title: "Exa Docs",
        url: "https://exa.ai/docs",
        publishedDate: "2026-04-09",
        author: "Exa",
        score: 0.98,
      },
    ],
  });

  assert.match(output, /Found 1 web result via exa-main:/);
  assert.match(output, /Exa Docs/);
  assert.match(output, /https:\/\/exa.ai\/docs/);
});

test("truncateText shortens long fetch bodies with an ellipsis", () => {
  assert.equal(truncateText("abcdef", 4), "abc…");
  assert.equal(truncateText("abc", 10), "abc");
});

test("formatFetchOutput includes both successful and failed URLs", () => {
  const output = formatFetchOutput(
    {
      providerName: "exa-main",
      results: [
        {
          url: "https://good.example",
          title: "Good",
          text: "This is a very long body that should be truncated in the final output.",
        },
        {
          url: "https://bad.example",
          title: null,
          error: "429 rate limited",
        },
      ],
    },
    { maxCharactersPerResult: 20 },
  );

  assert.match(output, /Status: ok/);
  assert.match(output, /Status: failed/);
  assert.match(output, /429 rate limited/);
  assert.match(output, /This is a very long…/);
});
```

- [x] **Step 2: Run the formatter tests to verify they fail**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/format.test.ts
```

Expected: `FAIL` with an `ERR_MODULE_NOT_FOUND` error for `./format.ts`.

- [x] **Step 3: Write the minimal formatter implementation**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/format.ts` with this content:

```ts
import type { NormalizedFetchResponse, NormalizedSearchResponse } from "./providers/types.ts";

export function truncateText(text: string, maxCharacters = 4000) {
  if (text.length <= maxCharacters) {
    return text;
  }
  return `${text.slice(0, Math.max(0, maxCharacters - 1))}…`;
}

export function formatSearchOutput(response: NormalizedSearchResponse) {
  if (response.results.length === 0) {
    return `No web results via ${response.providerName}.`;
  }

  const lines = [
    `Found ${response.results.length} web result${response.results.length === 1 ? "" : "s"} via ${response.providerName}:`,
  ];

  for (const [index, result] of response.results.entries()) {
    lines.push(`${index + 1}. ${result.title ?? "(untitled)"}`);
    lines.push(`   URL: ${result.url}`);

    const meta = [result.publishedDate, result.author].filter(Boolean);
    if (meta.length > 0) {
      lines.push(`   Meta: ${meta.join(" • ")}`);
    }

    if (typeof result.score === "number") {
      lines.push(`   Score: ${result.score}`);
    }
  }

  return lines.join("\n");
}

export interface FetchFormatOptions {
  maxCharactersPerResult?: number;
}

export function formatFetchOutput(response: NormalizedFetchResponse, options: FetchFormatOptions = {}) {
  const maxCharactersPerResult = options.maxCharactersPerResult ?? 4000;
  const lines = [
    `Fetched ${response.results.length} URL${response.results.length === 1 ? "" : "s"} via ${response.providerName}:`,
  ];

  for (const result of response.results) {
    lines.push("");
    lines.push(`URL: ${result.url}`);

    if (result.error) {
      lines.push("Status: failed");
      lines.push(`Error: ${result.error}`);
      continue;
    }

    lines.push("Status: ok");
    if (result.title) {
      lines.push(`Title: ${result.title}`);
    }
    if (result.summary) {
      lines.push(`Summary: ${result.summary}`);
    }
    if (result.highlights?.length) {
      lines.push("Highlights:");
      for (const highlight of result.highlights) {
        lines.push(`- ${highlight}`);
      }
    }
    if (result.text) {
      lines.push("Text:");
      lines.push(truncateText(result.text, maxCharactersPerResult));
    }
  }

  return lines.join("\n");
}
```

- [x] **Step 4: Run the formatter tests to verify they pass**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/format.test.ts
```

Expected: `PASS` for all three tests.

- [x] **Step 5: Commit the formatter layer**

Run:

```bash
git -C /home/alex/dotfiles add \
  .pi/agent/extensions/web-search/src/format.ts \
  .pi/agent/extensions/web-search/src/format.test.ts \
  docs/superpowers/plans/2026-04-09-web-search-tools.md

git -C /home/alex/dotfiles commit -m "test: add web tool output formatting"
```

### Task 4: Add the `web_search` tool and verify live search

**Files:**
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.test.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.test.ts`

- [ ] **Step 1: Write the failing `web_search` tool tests**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import { createWebSearchTool } from "./web-search.ts";

test("web_search executes metadata-only search through the resolved provider", async () => {
  let resolvedProviderName: string | undefined;

  const tool = createWebSearchTool({
    resolveProvider: async (providerName) => {
      resolvedProviderName = providerName;
      return {
        name: "exa-main",
        type: "exa",
        async search(request) {
          assert.equal(request.query, "exa docs");
          return {
            providerName: "exa-main",
            results: [
              {
                title: "Exa Docs",
                url: "https://exa.ai/docs",
                score: 0.98,
              },
            ],
          };
        },
        async fetch() {
          throw new Error("not used");
        },
      };
    },
  });

  const result = await tool.execute("tool-1", { query: "exa docs" }, undefined, undefined, undefined);

  assert.equal(resolvedProviderName, undefined);
  assert.match((result.content[0] as { text: string }).text, /Exa Docs/);
  assert.equal((result.details as { results: Array<{ url: string }> }).results[0]?.url, "https://exa.ai/docs");
});

test("web_search rejects a blank query before resolving a provider", async () => {
  const tool = createWebSearchTool({
    resolveProvider: async () => {
      throw new Error("should not resolve provider for a blank query");
    },
  });

  await assert.rejects(
    () => tool.execute("tool-1", { query: "   " }, undefined, undefined, undefined),
    /non-empty query/,
  );
});
```

- [ ] **Step 2: Run the `web_search` tests to verify they fail**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/tools/web-search.test.ts
```

Expected: `FAIL` with an `ERR_MODULE_NOT_FOUND` error for `./web-search.ts`.

- [ ] **Step 3: Write the minimal `web_search` tool implementation**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-search.ts` with this content:

```ts
import { Text } from "@mariozechner/pi-tui";
import { formatSearchOutput } from "../format.ts";
import type { NormalizedSearchResponse, WebProvider } from "../providers/types.ts";
import { WebSearchParamsSchema, type WebSearchParams } from "../schema.ts";

interface SearchToolDeps {
  resolveProvider(providerName?: string): Promise<WebProvider>;
}

function normalizeSearchQuery(query: string) {
  const trimmed = query.trim();
  if (!trimmed) {
    throw new Error("web_search requires a non-empty query.");
  }
  return trimmed;
}

export function createWebSearchTool({ resolveProvider }: SearchToolDeps) {
  return {
    name: "web_search",
    label: "Web Search",
    description: "Search the web through the configured provider. Returns result metadata by default.",
    parameters: WebSearchParamsSchema,

    async execute(_toolCallId: string, params: WebSearchParams) {
      const provider = await resolveProvider(params.provider);
      const response = await provider.search({
        query: normalizeSearchQuery(params.query),
        limit: params.limit,
        includeDomains: params.includeDomains,
        excludeDomains: params.excludeDomains,
        startPublishedDate: params.startPublishedDate,
        endPublishedDate: params.endPublishedDate,
        category: params.category,
        provider: params.provider,
      });

      return {
        content: [{ type: "text" as const, text: formatSearchOutput(response) }],
        details: response,
      };
    },

    renderCall(args: Partial<WebSearchParams>, theme: any) {
      let text = theme.fg("toolTitle", theme.bold("web_search "));
      text += theme.fg("muted", args.query ?? "");
      return new Text(text, 0, 0);
    },

    renderResult(result: { details?: NormalizedSearchResponse }, _options: unknown, theme: any) {
      const details = result.details;
      if (!details) {
        return new Text("", 0, 0);
      }

      const lines = [
        `${theme.fg("success", "✓ ")}${details.results.length} result${details.results.length === 1 ? "" : "s"} via ${details.providerName}`,
      ];

      for (const [index, item] of details.results.slice(0, 5).entries()) {
        lines.push(`  ${theme.fg("muted", `${index + 1}.`)} ${item.title ?? "(untitled)"} ${theme.fg("dim", item.url)}`);
      }

      return new Text(lines.join("\n"), 0, 0);
    },
  };
}
```

- [ ] **Step 4: Run the `web_search` tests to verify they pass**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/tools/web-search.test.ts
```

Expected: `PASS` for both tests.

- [ ] **Step 5: Create a real Exa config file for the live smoke test**

Run:

```bash
read -rsp "Exa API key: " EXA_KEY && printf '\n'
mkdir -p /home/alex/.pi/agent
cat > /home/alex/.pi/agent/web-search.json <<JSON
{
  "defaultProvider": "exa-main",
  "providers": [
    {
      "name": "exa-main",
      "type": "exa",
      "apiKey": "${EXA_KEY}",
      "options": {
        "defaultSearchLimit": 5,
        "defaultFetchTextMaxCharacters": 12000
      }
    }
  ]
}
JSON
chmod 600 /home/alex/.pi/agent/web-search.json
unset EXA_KEY
```

Expected: `/home/alex/.pi/agent/web-search.json` exists with mode `600`.

- [ ] **Step 6: Add a temporary entrypoint that registers `web_search` and manually verify it live**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/index.ts` with this content:

```ts
import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
import { loadWebSearchConfig } from "./src/config.ts";
import { createExaProvider } from "./src/providers/exa.ts";
import type { WebProvider } from "./src/providers/types.ts";
import { createWebSearchTool } from "./src/tools/web-search.ts";

async function resolveProvider(providerName?: string): Promise<WebProvider> {
  const config = await loadWebSearchConfig();
  const selectedName = providerName ?? config.defaultProviderName;
  const providerConfig = config.providersByName.get(selectedName);

  if (!providerConfig) {
    throw new Error(
      `Unknown web-search provider \"${selectedName}\". Configured providers: ${[...config.providersByName.keys()].join(", ")}`,
    );
  }

  switch (providerConfig.type) {
    case "exa":
      return createExaProvider(providerConfig);
    default:
      throw new Error(`Unsupported web-search provider type: ${(providerConfig as { type: string }).type}`);
  }
}

export default function webSearch(pi: ExtensionAPI) {
  pi.registerTool(createWebSearchTool({ resolveProvider }));
}
```

Then run:

```bash
cd /home/alex/dotfiles
pi
```

Inside pi, run this sequence:

```text
/reload
Search the web for Exa docs using the web_search tool.
```

Expected manual checks:

- the agent has a `web_search` tool available
- the tool call row shows `web_search` and the query text
- the result contains metadata-only output, not fetched page text
- at least one result includes `https://exa.ai/docs`

- [ ] **Step 7: Commit the `web_search` tool**

Run:

```bash
git -C /home/alex/dotfiles add \
  .pi/agent/extensions/web-search/index.ts \
  .pi/agent/extensions/web-search/src/tools/web-search.ts \
  .pi/agent/extensions/web-search/src/tools/web-search.test.ts \
  docs/superpowers/plans/2026-04-09-web-search-tools.md

git -C /home/alex/dotfiles commit -m "feat: add web_search tool"
```

### Task 5: Add `web_fetch`, register both tools, and verify batch fetch behavior

**Files:**
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.test.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.ts`
- Create: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/extension.test.ts`
- Modify: `/home/alex/dotfiles/.pi/agent/extensions/web-search/index.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.test.ts`
- Test: `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/extension.test.ts`

- [ ] **Step 1: Write the failing `web_fetch` and extension registration tests**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import { createWebFetchTool } from "./web-fetch.ts";

test("web_fetch prepareArguments folds a single url into urls", () => {
  const tool = createWebFetchTool({
    resolveProvider: async () => {
      throw new Error("not used");
    },
  });

  assert.deepEqual(tool.prepareArguments?.({ url: "https://exa.ai/docs" }), {
    url: "https://exa.ai/docs",
    urls: ["https://exa.ai/docs"],
  });
});

test("web_fetch defaults to text and returns formatted fetch results", async () => {
  let capturedRequest: Record<string, unknown> | undefined;

  const tool = createWebFetchTool({
    resolveProvider: async () => ({
      name: "exa-main",
      type: "exa",
      async search() {
        throw new Error("not used");
      },
      async fetch(request) {
        capturedRequest = request as unknown as Record<string, unknown>;
        return {
          providerName: "exa-main",
          results: [
            {
              url: "https://exa.ai/docs",
              title: "Docs",
              text: "Body",
            },
          ],
        };
      },
    }),
  });

  const result = await tool.execute("tool-1", { urls: ["https://exa.ai/docs"] }, undefined, undefined, undefined);

  assert.equal(capturedRequest?.text, true);
  assert.match((result.content[0] as { text: string }).text, /Body/);
  assert.equal((result.details as { results: Array<{ title: string }> }).results[0]?.title, "Docs");
});

test("web_fetch rejects malformed URLs", async () => {
  const tool = createWebFetchTool({
    resolveProvider: async () => {
      throw new Error("should not resolve provider for invalid URLs");
    },
  });

  await assert.rejects(
    () => tool.execute("tool-1", { urls: ["not-a-url"] }, undefined, undefined, undefined),
    /Invalid URL/,
  );
});
```

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/extension.test.ts` with this content:

```ts
import test from "node:test";
import assert from "node:assert/strict";
import webSearchExtension from "../index.ts";

test("the extension entrypoint registers both web_search and web_fetch", () => {
  const registeredTools: string[] = [];

  webSearchExtension({
    registerTool(tool: { name: string }) {
      registeredTools.push(tool.name);
    },
  } as any);

  assert.deepEqual(registeredTools, ["web_search", "web_fetch"]);
});
```

- [ ] **Step 2: Run the new tests to verify they fail**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/tools/web-fetch.test.ts src/extension.test.ts
```

Expected: `FAIL` with an `ERR_MODULE_NOT_FOUND` error for `./web-fetch.ts`.

- [ ] **Step 3: Write the minimal `web_fetch` tool implementation**

Create `/home/alex/dotfiles/.pi/agent/extensions/web-search/src/tools/web-fetch.ts` with this content:

```ts
import { Text } from "@mariozechner/pi-tui";
import { formatFetchOutput } from "../format.ts";
import type { NormalizedFetchResponse, WebProvider } from "../providers/types.ts";
import { WebFetchParamsSchema, type WebFetchParams } from "../schema.ts";

interface FetchToolDeps {
  resolveProvider(providerName?: string): Promise<WebProvider>;
}

function normalizeUrl(value: string) {
  try {
    return new URL(value).toString();
  } catch {
    throw new Error(`Invalid URL: ${value}`);
  }
}

function normalizeFetchParams(params: WebFetchParams & { url?: string }) {
  const urls = (Array.isArray(params.urls) ? params.urls : []).map(normalizeUrl);
  if (urls.length === 0) {
    throw new Error("web_fetch requires at least one URL.");
  }

  return {
    urls,
    text: params.text ?? (!params.highlights && !params.summary),
    highlights: params.highlights ?? false,
    summary: params.summary ?? false,
    textMaxCharacters: params.textMaxCharacters,
    provider: params.provider,
  };
}

export function createWebFetchTool({ resolveProvider }: FetchToolDeps) {
  return {
    name: "web_fetch",
    label: "Web Fetch",
    description: "Fetch page contents through the configured provider. Returns text by default.",
    parameters: WebFetchParamsSchema,

    prepareArguments(args: unknown) {
      if (!args || typeof args !== "object") {
        return args;
      }

      const input = args as { url?: unknown; urls?: unknown };
      if (typeof input.url === "string" && !Array.isArray(input.urls)) {
        return {
          ...input,
          urls: [input.url],
        };
      }

      return args;
    },

    async execute(_toolCallId: string, params: WebFetchParams) {
      const normalized = normalizeFetchParams(params as WebFetchParams & { url?: string });
      const provider = await resolveProvider(normalized.provider);
      const response = await provider.fetch(normalized);

      return {
        content: [{ type: "text" as const, text: formatFetchOutput(response) }],
        details: response,
      };
    },

    renderCall(args: Partial<WebFetchParams> & { url?: string }, theme: any) {
      const urls = Array.isArray(args.urls) ? args.urls : typeof args.url === "string" ? [args.url] : [];
      let text = theme.fg("toolTitle", theme.bold("web_fetch "));
      text += theme.fg("muted", `${urls.length} url${urls.length === 1 ? "" : "s"}`);
      return new Text(text, 0, 0);
    },

    renderResult(result: { details?: NormalizedFetchResponse }, _options: unknown, theme: any) {
      const details = result.details;
      if (!details) {
        return new Text("", 0, 0);
      }

      const failed = details.results.filter((item) => item.error).length;
      const succeeded = details.results.length - failed;
      return new Text(
        `${theme.fg("success", "✓ ")}${succeeded} ok${failed ? ` • ${theme.fg("warning", `${failed} failed`)}` : ""}`,
        0,
        0,
      );
    },
  };
}
```

- [ ] **Step 4: Replace the temporary entrypoint with the final entrypoint that registers both tools**

Replace `/home/alex/dotfiles/.pi/agent/extensions/web-search/index.ts` with this content:

```ts
import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
import { loadWebSearchConfig } from "./src/config.ts";
import { createExaProvider } from "./src/providers/exa.ts";
import type { WebProvider } from "./src/providers/types.ts";
import { createWebFetchTool } from "./src/tools/web-fetch.ts";
import { createWebSearchTool } from "./src/tools/web-search.ts";

async function resolveProvider(providerName?: string): Promise<WebProvider> {
  const config = await loadWebSearchConfig();
  const selectedName = providerName ?? config.defaultProviderName;
  const providerConfig = config.providersByName.get(selectedName);

  if (!providerConfig) {
    throw new Error(
      `Unknown web-search provider \"${selectedName}\". Configured providers: ${[...config.providersByName.keys()].join(", ")}`,
    );
  }

  switch (providerConfig.type) {
    case "exa":
      return createExaProvider(providerConfig);
    default:
      throw new Error(`Unsupported web-search provider type: ${(providerConfig as { type: string }).type}`);
  }
}

export default function webSearch(pi: ExtensionAPI) {
  pi.registerTool(createWebSearchTool({ resolveProvider }));
  pi.registerTool(createWebFetchTool({ resolveProvider }));
}
```

- [ ] **Step 5: Run the `web_fetch` and entrypoint smoke tests to verify they pass**

Run:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npx tsx --test src/tools/web-fetch.test.ts src/extension.test.ts
```

Expected: `PASS` for all four tests.

- [ ] **Step 6: Reload pi and manually verify search + single fetch + batch fetch**

Run:

```bash
cd /home/alex/dotfiles
pi
```

Inside pi, run this sequence:

```text
/reload
Search the web for Exa docs using the web_search tool.
Then fetch https://exa.ai/docs using the web_fetch tool.
Then fetch https://exa.ai/docs and https://exa.ai using the web_fetch tool.
```

Expected manual checks:

- both `web_search` and `web_fetch` are available
- `web_search` still returns metadata only by default
- `web_fetch` returns page text by default
- `web_fetch` accepts multiple URLs in one call
- batch fetch output is clearly separated per URL
- if one URL fails, the result still includes the successful URL output and a failure section for the bad URL

- [ ] **Step 7: Commit the completed web tools extension**

Run:

```bash
git -C /home/alex/dotfiles add \
  .pi/agent/extensions/web-search/index.ts \
  .pi/agent/extensions/web-search/src/tools/web-fetch.ts \
  .pi/agent/extensions/web-search/src/tools/web-fetch.test.ts \
  .pi/agent/extensions/web-search/src/extension.test.ts \
  docs/superpowers/plans/2026-04-09-web-search-tools.md

git -C /home/alex/dotfiles commit -m "feat: add web search tools extension"
```

## Final Verification Checklist

Run these before claiming the work is complete:

```bash
cd /home/alex/dotfiles/.pi/agent/extensions/web-search
npm test
```

Expected: `PASS` for all config, provider, formatter, tool, and entrypoint tests.

Then run pi from `/home/alex/dotfiles`, use `/reload`, and manually verify:

1. `web_search` returns metadata-only results
2. `web_search` handles a configured Exa provider successfully
3. `web_fetch` returns text by default
4. `web_fetch` accepts a single URL
5. `web_fetch` accepts multiple URLs
6. invalid URLs fail before the provider is called
7. missing or invalid `~/.pi/agent/web-search.json` produces a helpful error
8. both tools remain available after `/reload`

If any of those checks fail, do not mark the work complete.