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W0-B spike:Pi SDK(pi-agent-core / pi-ai 0.87.1)验证记录

  • 日期:2026-09-27;Node v24.15.0;@earendil-works/[email protected]、@earendil-works/[email protected](依赖 @earendil-works/chord、pi-telemetry、[email protected])
  • 代码:spikes/pi/(common.ts 工具与脚本化模型、fake-run.ts、abort-resume.ts、compaction.ts、provider-config.ts)
  • 参考:包内 README / .d.ts;GitHub earendil-works/pi tag v0.87.1 的 packages/agent/docs/harness.md(AgentHarness 规范)、packages/agent/test/harness/runtime/drive-public.test.ts、packages/coding-agent/examples/sdk/12-full-control.ts
  • 结论见 docs/adr/ADR-003-pi-integration.md

0. 该用哪一层

层 包 说明 结论
Agent / agentLoop pi-agent-core 进程内状态,无持久化 不用
AgentHarness + AgentLane pi-agent-core 持久会话(entry 树 + 操作状态机),有 prompt/resume/abort/compact、事件、hooks、工具重放策略;不做任何隐式发现 采用
createAgentSession / AgentSession pi-coding-agent 编码助手层:ResourceLoader 会发现扩展、skills、AGENTS.md,内置 read/bash 等工具,依赖 pi-tui、jiti(运行时加载 TS 扩展)、photon 不用。REQ §10.1 说的"AgentSession 层"在 0.87.1 里的对应物,就是 core 的 AgentHarness

grep 过 pi-agent-core dist:只有 harness/skills.js(显式调用的 loader)、env/nodejs.js(显式构造的执行环境)、pico3/jsonl.js 会接触文件系统。AgentHarness.create() 只使用传入的 tools / resources / systemPrompt,不读取 cwd、home、.pi/、AGENTS.md。

1. 关键 API 形状

import { createModels, createProvider, fauxProvider, fauxAssistantMessage, fauxToolCall, fauxText } from "@earendil-works/pi-ai";
import { AgentHarness, BACKGROUND_CONTEXT, MemorySessionRepo, JsonlSessionRepo, type AgentHarnessTool } from "@earendil-works/pi-agent-core";

const models = createModels(); models.setProvider(provider);
const session = await new MemorySessionRepo().create({ id }, ctx);          // 或 JsonlSessionRepo({ fileSystem, sessionsRoot })
const { harness, open } = await AgentHarness.create({
  session, models, model,
  systemPrompt, tools: [/* AgentHarnessTool */], toolContext: { actorId, grants },  // toolContext 可为 (ctx)=>T
  activeToolNames?, thinkingLevel: "off"|"minimal"|"low"|"medium"|"high"|"xhigh"|"max",
  compaction: { enabled, reserveTokens, keepRecentTokens },
  retry: { enabled, maxRetries, baseDelayMs, maxAgentDelayMs? },
  streamOptions: { timeoutMs, maxRetries, headers, metadata, cacheRetention, deferred },
  toolExecution: "sequential" | "parallel", resources?: { skills, promptTemplates },
}, ctx);                                                  // open = 附着时发现的未完成操作
const lane = await harness.lane("main", ctx);
await lane.prompt(text, undefined, ctx) / lane.resume(ctx) / lane.abort(ctx) / lane.compact({ customInstructions }, ctx)
lane.accept({kind:"prompt",operationId,prompt}) + lane.drive({operationId}) + lane.requestAbort(operationId)   // 低层原语,可由外部调度器驱动
harness.events.on("tool_start" | "tool_end" | "message_update" | "run_end" | "usage" | "compaction_end" | …, listener)
harness.hooks.on("before_tool" | "after_tool" | "before_request" | "before_payload" | "transform_context" | "before_compaction" | …, handler)
lane.setModel({provider, modelId}) / setThinkingLevel / setActiveTools;harness.setTools / setCompactionSettings / setRetryPolicy

工具:

const t: AgentHarnessTool<Ctx> = {
  name, label, description, parameters: Type.Object({...}),   // typebox 1.x
  replay: "safe" | "never",      // 崩溃后:safe = 用持久化的参数重跑;never = 合成"执行被中断、结果未知"的错误结果
  executionMode?: "sequential",
  async execute(toolCallId, params, onUpdate, toolContext, invocation /* invocationId, getMemo/setMemo */, context /* context.abortSignal */) {
    return { content: [{ type: "text", text }], details };     // 失败直接 throw → isError:true
  },
};

2. 验证结果

2.1 fake 模型驱动两个工具 + 流式事件 —— 通过(npx tsx pi/fake-run.ts)

fake 模型用 fauxProvider + FauxResponseFactory(函数收到 transcript,按上一个工具结果决定下一步)实现,不需要 API Key。

[run_start] lane=main
[turn_start] lane=main
  [text_delta] "我先查一下库里有没有《D"
  [text_delta] "une》。"
  [toolcall_end] inventory__query
[usage] in=145 totals.input=145 output=18
  [hook before_tool] inventory__query args={"title":"Dune","year":2021}
[tool_start] inventory__query {"title":"Dune","year":2021}
[tool_update] lane=main
[tool_end] inventory__query isError=false -> "{\"title\":\"Dune\",\"inLibrary\":false,\"versions\":[]}"
[turn_end] lane=main
[turn_start] lane=main
  [text_delta] "库里没有,提交 1080" …
  [toolcall_end] download__submit
  [toolcall_end] bash
  [hook before_tool] download__submit args={"title":"Dune","quality":"1080p"}
[tool_start] download__submit {"title":"Dune","quality":"1080p"}
[tool_end] download__submit isError=false -> "{\"accepted\":true,\"idempotencyKey\":\"dl:Dune:1080p\",\"status\":\"submitted\"}"
[tool_start] bash {"command":"rm -rf /"}
[tool_end] bash isError=true -> "Tool \"bash\" is unavailable"       ← 不在白名单的工具被合成错误结果,不执行
[turn_start] … [text_delta] "下载已提交(仅代表已提交,不代表已入库)…"
[run_end] status=completed
RESULT {"ok":true,"value":{"operationId":"01a0e235-…","kind":"run","status":"completed",…}}
SUBMITTED [{"key":"dl:Dune:1080p","title":"Dune"}] fake calls: 3

2.2 AbortSignal 取消 —— 通过(SUBMIT_DELAY_MS=5000 npx tsx pi/abort-resume.ts abort)

[tool_start] download__submit
>> lane.abort()
[operation_abort]
[tool_end] download__submit  "aborted by signal"                      ← execute 里的 context.abortSignal 触发了
[tool_end] bash  "Tool execution was cancelled before completion."   ← 同批次尚未执行的调用被合成为取消结果
[run_end]  aborted
PROMPT RESULT {…"status":"aborted"…}

2.3 会话持久化与崩溃恢复 —— 通过(JSONL)

进程 1(crash)在 download.submit 执行中 SIGKILL 自己;进程 2(resume)打开同一个 JSONL 会话:

found session crash-demo …/.sessions/--opt-uhd_media_tool-spikes-pi-.sessions--/2026-09-27T09-33-19-828Z_crash-demo.jsonl
open operations at attach: [{"lane":"main","operationId":"01a0e236-3a62-…","kind":"run","startedAt":1790501599842}]
[tool_end] (recovery) download__submit "[Tool execution was interrupted. … the external outcome is unknown.]"   ← replay:"never" 不重跑
[tool_start] (recovery) bash / [tool_end] (recovery) bash "Tool \"bash\" is unavailable"
[run_end]  completed
fake calls: 1                                                     ← 只多请求一次模型;inventory.query 没有重跑

恢复时 download.submit 得到的是"结果未知"。业务侧要按 invocationId 或服务端幂等键去操作账本对账,不能让模型重新提交一次。

2.4 压缩 —— 手动通过,阈值触发可见(compaction.ts)

[compaction_start] reason=manual / [compaction_end] reason=manual status=completed
REPEAT=400:[compaction_start] reason=threshold → [compaction_end] status=completed
            单条输入本身超过 contextWindow 时 run 失败:{"code":"assistant_error","message":"Assistant request exceeded the context window"}
entry types: compaction,message,…

摘要本身也是一次模型调用(fake 模型按脚本返回)。压缩提示词可以通过 customInstructions 或 before_compaction hook 定制。

2.5 真实 provider 类型的配置(不出外网)—— 通过(provider-config.ts)

用 createProvider 分别套 anthropic-messages 和 openai-completions 两种 API 实现,baseUrl 指向脚本自带的本地抓包服务器(返回 400):

builtin anthropic models (first 5): claude-fable-5, claude-fable-5-1, claude-haiku-4-5, …
builtin anthropic auth configured without env? undefined
supported thinking levels, custom anthropic model: off,minimal,low,medium,high
[before_request] upstream-anthropic/claude-sonnet-4-5 step=assistant attempt=1
[upstream-anthropic] run: {"status":"failed","error":{"code":"assistant_error","message":"400 {…capture server: refusing on purpose…}"}}
CAPTURED POST /v1/messages?beta=true auth=sk-test-anthropic
   model=claude-sonnet-4-5 max_tokens=8192 thinking={"type":"enabled","budget_tokens":7168,"display":"summarized"} tools=["inventory__query"] stream=true
CAPTURED POST /v1/chat/completions auth=Bearer sk-test-openai
   model=qwen3-235b max_tokens=8192 thinking=true tools=["inventory__query"] stream=true

配置字段:

  • Model:id(上游模型名)、api(anthropic-messages | openai-completions | openai-responses | …)、provider、baseUrl、reasoning、thinkingLevelMap、contextWindow、maxTokens、cost、headers、compat(OpenAI 兼容上游的差异开关,如 supportsDeveloperRole、thinkingFormat、maxTokensField)。
  • baseUrl 的拼接方式:Anthropic 写 不带 /v1 的根地址(SDK 自己拼 /v1/messages);OpenAI 兼容写 带 /v1 的地址(SDK 拼 /chat/completions)。
  • apiKey:createProvider({ auth: { apiKey: { name, resolve: async () => ({ auth: { apiKey, baseUrl?, headers? } }) } } }),每次请求时解析,可以接我们自己的 secret store。内置 provider 用 envApiKeyAuth 读环境变量(如 ANTHROPIC_API_KEY),也可以用 createModels({ credentials }) 注入。
  • 思考档位:thinkingLevel 映射到上游参数(Anthropic high → budget_tokens 7168),可用 getSupportedThinkingLevels(model) / clampThinkingLevel 查询。
  • 上下文预算:model.contextWindow(可以自定义成比上游小的值)配合 compaction.reserveTokens/keepRecentTokens。

3. 不支持 / 未验证

  • 子代理:pi-agent-core 和 pi-ai 里都没有子代理概念(dist 里 grep 不到)。设置页的"子代理开关"要由我们自己实现,例如在工具里开一个新 lane 或新会话,并继承预算和授权。
  • 工具名不能带点:inventory.query 这种名字上游(Anthropic/OpenAI 要求 ^[a-zA-Z0-9_-]{1,64}$)不接受,本 spike 统一映射成 inventory__query。pi 自身是否校验名字未验证。
  • PostgreSQL 会话存储:0.87.1 只提供 Memory / JSONL / SQLite(独立包 pi-session-backend-sqlite-node,未验证)。Postgres 分区存储在规范 Part 6 里标注为 future。存储格式 4 仍是 WIP,不保证迁移。
  • watchSession 未实现(规范 R12);遥测只有部分实现。
  • 模型流式输出中途崩溃的恢复(合成 error 后按 retry 重试)只读了规范,没有实测。
  • pi-coding-agent 的 createAgentSession / ResourceLoader 没有安装,也没有运行(按上文结论不采用)。
  • 与真实上游联网调用:没有(不需要 key)。