Pi Agent 运行时架构

const sessionLane = resolveSessionLane(params.sessionKey?.trim() || params.sessionId);
const globalLane = resolveGlobalLane(params.lane);

// 目的：防止同 session 并发冲突，同时限制全局资源竞争
// Session Lane: session:{key}
// Global Lane: 可配置，默认为 "main"

const { model, error, authStorage, modelRegistry } = resolveModel(
  provider,
  modelId,
  agentDir,
  params.config,
);

if (!model) {
  throw new Error(error ?? `Unknown model: ${provider}/${modelId}`);
}

const ctxInfo = resolveContextWindowInfo({
  cfg: params.config,
  provider,
  modelId,
  modelContextWindow: model.contextWindow,
  defaultTokens: DEFAULT_CONTEXT_TOKENS,
});

const ctxGuard = evaluateContextWindowGuard({
  info: ctxInfo,
  warnBelowTokens: CONTEXT_WINDOW_WARN_BELOW_TOKENS,
  hardMinTokens: CONTEXT_WINDOW_HARD_MIN_TOKENS,
});

if (ctxGuard.shouldBlock) {
  throw new FailoverError(
    `Model context window too small (${ctxGuard.tokens} tokens). Minimum is ${CONTEXT_WINDOW_HARD_MIN_TOKENS}.`,
    { reason: "unknown", provider, model: modelId },
  );
}

subscribeEmbeddedPiSession({
  session,
  runId,
  onPartialReply,      // 文本增量回调
  onToolResult,       // 工具结果回调
  onAgentEvent,       // Agent 事件回调
  ...
})

SessionManager.open(sessionFile)
createAgentSession({
  cwd,
  agentDir,
  model,
  systemPrompt,
  tools: builtInTools,
  customTools: allCustomTools,
  sessionManager,
  settingsManager,
  ...
})

buildEmbeddedSystemPrompt({
  workspaceDir,
  tools,
  runtimeInfo: { host, os, arch, { node, model, channel, capabilities, channelActions },
  sandboxInfo,
  skillsPrompt,
  heartbeatPrompt,
  docsPath,
  reactionGuidance,
  messageToolHints,
  contextFiles,
{  ...
})

calculateAuthProfileCooldownMs(failureReason, failureCount)
markAuthProfileCooldown({ store, profileId, failureReason, cfg, agentDir })
isProfileInCooldown(authStore, profileId)

const BASE_COOLDOWN_MS = 60_000; // 1 分钟
const MAX_COOLDOWN_MS = 5 * 60_000; // 5 分钟

// 基于失败原因和失败次数指数退避
// 限制最大冷却时间

resolveSandboxRuntimeStatus({ cfg, sessionKey })

shouldSandboxSession(cfg, sessionKey, mainSessionKey)

ensureSandboxContainer({
  sessionKey,
  workspaceDir,
  agentWorkspaceDir,
  cfg
})

resolveSandboxToolPolicyForAgent(cfg, agentId)
isToolAllowed(policy, toolName)

{
  sessionId, sessionKey,
  messageChannel, messageProvider,
  agentAccountId, messageTo, messageThreadId,
  groupId, groupChannel, groupSpace,
  sessionFile, workspaceDir, agentDir,
  prompt, images,
  provider, modelId, model,
  authStorage, modelRegistry,
  thinkLevel, reasoningLevel,
  timeoutMs, runId, abortSignal,
  onPartialReply, onToolResult, onAgentEvent,
  ...
}

{
  enabled, sessionKey,
  workspaceDir, agentWorkspaceDir,
  workspaceAccess, // "none" | "ro" | "rw"
  containerName, containerWorkdir,
  docker, tools,
  browserAllowHostControl,
  browser? // { bridgeUrl, noVncUrl, containerName }
}

{
  apiKey?, profileId?, source,
  mode: "api-key" | "oauth" | "token" | "aws-sdk"
}