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217/**
* Copyright (c) Microsoft Corporation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import fs from 'fs';
import path from 'path';
import { toolsForLoop } from './tool';
import { debug } from '../../utilsBundle';
import { Loop, z as zod } from '../../mcpBundle';
import { runAction } from './actionRunner';
import { Context } from './context';
import performTools from './performTools';
import expectTools from './expectTools';
import * as actions from './actions';
import type { ToolDefinition } from './tool';
import type * as loopTypes from '@lowire/loop';
import type { Progress } from '../progress';
export type CallParams = {
cacheKey?: string;
maxTokens?: number;
maxActions?: number;
maxActionRetries?: number;
};
export async function pageAgentPerform(progress: Progress, context: Context, userTask: string, callParams: CallParams) {
const cacheKey = (callParams.cacheKey ?? userTask).trim();
if (await cachedPerform(progress, context, cacheKey))
return;
const task = `
### Instructions
- Perform the following task on the page.
- Your reply should be a tool call that performs action the page".
### Task
${userTask}
`;
await runLoop(progress, context, performTools, task, undefined, callParams);
await updateCache(context, cacheKey);
}
export async function pageAgentExpect(progress: Progress, context: Context, expectation: string, callParams: CallParams) {
const cacheKey = (callParams.cacheKey ?? expectation).trim();
if (await cachedPerform(progress, context, cacheKey))
return;
const task = `
### Instructions
- Call one of the "browser_expect_*" tools to verify / assert the condition.
- You can call exactly one tool and it can't be report_results, must be one of the assertion tools.
### Expectation
${expectation}
`;
await runLoop(progress, context, expectTools, task, undefined, callParams);
await updateCache(context, cacheKey);
}
export async function pageAgentExtract(progress: Progress, context: Context, query: string, schema: loopTypes.Schema, callParams: CallParams): Promise<any> {
const task = `
### Instructions
Extract the following information from the page. Do not perform any actions, just extract the information.
### Query
${query}`;
const { result } = await runLoop(progress, context, [], task, schema, callParams);
return result;
}
async function runLoop(progress: Progress, context: Context, toolDefinitions: ToolDefinition[], userTask: string, resultSchema: loopTypes.Schema | undefined, params: CallParams): Promise<{
result: any
}> {
const { page } = context;
if (!context.agentParams.api || !context.agentParams.model)
throw new Error(`This action requires the API and API key to be set on the page agent. Did you mean to --run-agents=missing?`);
if (!context.agentParams.apiKey)
throw new Error(`This action requires API key to be set on the page agent.`);
const { full } = await page.snapshotForAI(progress);
const { tools, callTool, reportedResult, refusedToPerformReason } = toolsForLoop(progress, context, toolDefinitions, { resultSchema, refuseToPerform: 'allow' });
const secrets = Object.fromEntries((context.agentParams.secrets || [])?.map(s => ([s.name, s.value])));
const apiCacheTextBefore = context.agentParams.apiCacheFile ?
await fs.promises.readFile(context.agentParams.apiCacheFile, 'utf-8').catch(() => '{}') : '{}';
const apiCacheBefore = JSON.parse(apiCacheTextBefore);
const loop = new Loop({
api: context.agentParams.api as any,
apiEndpoint: context.agentParams.apiEndpoint,
apiKey: context.agentParams.apiKey,
apiTimeout: context.agentParams.apiTimeout ?? 0,
model: context.agentParams.model,
maxTokens: params.maxTokens ?? context.maxTokensRemaining(),
maxToolCalls: params.maxActions ?? context.agentParams.maxActions ?? 10,
maxToolCallRetries: params.maxActionRetries ?? context.agentParams.maxActionRetries ?? 3,
summarize: true,
debug,
callTool,
tools,
secrets,
cache: apiCacheBefore,
...context.events,
});
const task: string[] = [];
if (context.agentParams.systemPrompt) {
task.push('### System');
task.push(context.agentParams.systemPrompt);
task.push('');
}
task.push('### Task');
task.push(userTask);
if (context.history().length) {
task.push('### Context history');
task.push(context.history().map(h => `- ${h.type}: ${h.description}`).join('\n'));
task.push('');
}
task.push('### Page snapshot');
task.push(full);
task.push('');
const { error, usage } = await loop.run(task.join('\n'), { signal: progress.signal });
context.consumeTokens(usage.input + usage.output);
if (context.agentParams.apiCacheFile) {
const apiCacheAfter = { ...apiCacheBefore, ...loop.cache() };
const sortedCache = Object.fromEntries(Object.entries(apiCacheAfter).sort(([a], [b]) => a.localeCompare(b)));
const apiCacheTextAfter = JSON.stringify(sortedCache, undefined, 2);
if (apiCacheTextAfter !== apiCacheTextBefore) {
await fs.promises.mkdir(path.dirname(context.agentParams.apiCacheFile), { recursive: true });
await fs.promises.writeFile(context.agentParams.apiCacheFile, apiCacheTextAfter);
}
}
if (refusedToPerformReason())
throw new Error(`Agent refused to perform action: ${refusedToPerformReason()}`);
if (error)
throw new Error(`Agentic loop failed: ${error}`);
return { result: reportedResult ? reportedResult() : undefined };
}
async function cachedPerform(progress: Progress, context: Context, cacheKey: string): Promise<actions.ActionWithCode[] | undefined> {
if (!context.agentParams?.cacheFile)
return;
const cache = await cachedActions(context.agentParams?.cacheFile);
const entry = cache.actions[cacheKey];
if (!entry)
return;
for (const action of entry.actions)
await runAction(progress, 'run', context.page, action, context.agentParams.secrets ?? []);
return entry.actions;
}
async function updateCache(context: Context, cacheKey: string) {
const cacheFile = context.agentParams?.cacheFile;
const cacheOutFile = context.agentParams?.cacheOutFile;
const cacheFileKey = cacheFile ?? cacheOutFile;
const cache = cacheFileKey ? await cachedActions(cacheFileKey) : { actions: {}, newActions: {} };
const newEntry = { actions: context.actions() };
cache.actions[cacheKey] = newEntry;
cache.newActions[cacheKey] = newEntry;
if (cacheOutFile) {
const entries = Object.entries(cache.newActions);
entries.sort((e1, e2) => e1[0].localeCompare(e2[0]));
await fs.promises.writeFile(cacheOutFile, JSON.stringify(Object.fromEntries(entries), undefined, 2));
} else if (cacheFile) {
const entries = Object.entries(cache.actions);
entries.sort((e1, e2) => e1[0].localeCompare(e2[0]));
await fs.promises.writeFile(cacheFile, JSON.stringify(Object.fromEntries(entries), undefined, 2));
}
}
type Cache = {
actions: actions.CachedActions;
newActions: actions.CachedActions;
};
const allCaches = new Map<string, Cache>();
async function cachedActions(cacheFile: string): Promise<Cache> {
let cache = allCaches.get(cacheFile);
if (!cache) {
const json = await fs.promises.readFile(cacheFile, 'utf-8').then(text => JSON.parse(text)).catch(() => ({}));
const parsed = actions.cachedActionsSchema.safeParse(json);
if (parsed.error)
throw new Error(`Failed to parse cache file ${cacheFile}:\n${zod.prettifyError(parsed.error)}`);
cache = { actions: parsed.data, newActions: {} };
allCaches.set(cacheFile, cache);
}
return cache;
}