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OpenAI

2026年4月27日

工程

Codex 協調的開源規格:Symphony

作者:Alex Kotliarskyi、Victor Zhu 及 Zach Brock

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六個月前,當我們在開發一個內部生產力工具時,團隊作出了一個當時頗具爭議的決定:我們要在程式碼庫中完全不寫任何人手撰寫的程式碼。我們專案程式碼庫中的每一行,都必須由 Codex 生成。

為了實現這一點,我們從零開始重新設計工程工作流程。我們建立了適合智能代理使用的程式碼庫,大量投入於自動化測試及安全護欄,並將 Codex 視為完整的團隊成員。我們已在之前 關於框架工程的網誌文章中記錄了這段歷程。

而且這的確有效,但接著我們遇上了下一個瓶頸:上下文切換。

為了解決這個新問題,我們建立了一個名為 Symphony 的系統。Symphony(在新視窗中開啟) 是一個智能代理協調器,可將像 Linear 這樣的項目管理看板轉化為編碼智能代理的控制平面。每個開放中的任務都會分配到一個智能代理,智能代理會持續運行,而人類則負責審查結果。

本文說明我們如何建立 Symphony,令部分團隊成功合併的合併請求增加 500%,以及如何使用它將你的問題追蹤工具變成全天候運作的智能代理協調器。

互動式編碼智能代理的上限

即使越來越容易使用,編碼智能代理(無論是透過網頁應用程式還是 CLI 使用)本質上仍然是互動式工具。

隨着 OpenAI 內部的智能代理工作規模增加,我們發現了一種新的負擔。每位工程師都會開幾個 Codex 工作階段、分派任務、審查輸出、引導智能代理,然後重複。在實際情況下,大多數人同時舒適地管理三至五個工作階段就已經是極限,再多就會因上下文切換而感到吃力。超過這個數量後,生產力就會下降。我們會忘記哪個工作階段在做甚麼,要在不同終端機之間跳來跳去,提醒智能代理重新回到正軌,還要除錯那些進行到一半就卡住的長時間任務。

智能代理本身很快,但我們遇到的是系統瓶頸:人類注意力。我們其實等同建立了一支能力極強的初級工程師團隊,然後要求人類工程師去事無大小地管理他們。這種方式不可能擴展。

視角的轉變

我們意識到自己一直在優化錯的東西。我們一直圍繞編碼工作階段和已合併 PR 來設計系統,但 PR 和工作階段其實只是達成目的的手段。軟件工作流程大多圍繞交付項目組織,例如問題、任務、支援票證和里程碑。

於是我們開始思考:如果我們不再直接監督智能代理,而是讓它們從任務追蹤器自行接工作,會發生甚麼事?

這個想法後來變成了 Symphony,一份書面規格,作為監督者來協調智能代理工作。

將我們的問題追蹤工具變成智能代理協調器

Symphony 的起點是一個簡單概念:任何開放中的任務都應由智能代理接手並完成。我們不再於多個分頁中管理 Codex 工作階段,而是將問題追蹤工具變成控制平面。

在這個設定中,每個開放中的 Linear 問題都會對應到一個專用的智能代理工作區。Symphony 會持續監察任務看板,並確保每個進行中的任務都有一個智能代理在循環中運行,直到完成為止。如果智能代理崩潰或停滯,Symphony 會重新啟動它。如果有新工作出現,Symphony 就會接手並開始組織工作。

我們的工作流程是以支援票證狀態為基礎建立的,並把任務管理工具 Linear 當作狀態機使用。

Coding agents use Linear as a state machine to work alongside us.

在實際運作中,Symphony 會把工作與工作階段及 pull request 解耦。有些問題會在不同程式碼庫中產生多個 PR;另一些則純粹是調查或分析,完全不會碰到程式碼庫。

一旦以這種方式抽象化工作,支援票證就能代表大得多的工作單位。

我們經常使用 Symphony 來協調複雜功能與基礎設施遷移。例如,我們可能會建立一個任務,要求智能代理分析程式碼庫、Slack 或 Notion,並產出一份實作計劃。當我們對計劃感到滿意後,智能代理便會生成一個任務樹,把工作拆分成不同階段,並定義各任務之間的依賴關係。

智能代理只會開始處理未受阻的任務,因此在這個 DAG(由一連串執行步驟組成)中,工作會自然且以最佳方式並行推進。在以下例子中,我們將 React 升級標記為受遷移至 Vite 所阻礙。正如預期,智能代理只在完成遷移至 Vite 後,才開始升級 React。

智能代理亦可以自行建立工作。在實作或審查期間,它們往往會留意到目前任務範圍以外的改進空間,例如效能問題、重構機會或更好的架構。遇到這類情況時,它們只需建立新的問題,讓我們稍後評估並排期處理;當中不少後續任務亦會由智能代理接手。雖然整個流程由我們監督,但智能代理能保持工作井然有序,並持續推進進度。

這種工作方式大幅降低了啟動含糊工作的認知成本。即使智能代理做錯了,仍然能提供有用資訊,而且對我們來說成本接近零。我們可以很低成本地建立支援票證,讓智能代理製作原型和探索,然後捨棄任何我們不滿意的探索結果。

由於協調器在開發環境中運行且從不停止,我們可以隨時隨地新增任務,並確保會有智能代理接手。例如,我們團隊有位工程師在一個網絡不穩的木屋內,透過手機上的 Linear 應用程式完成了三項重要變更。

以這種方式工作帶來更高的探索度

觀察以 Symphony 工作所帶來的影響時,最明顯的變化是產出。OpenAI 部分團隊在首三週看到成功合併的 PR 數量增加 6 倍。在 OpenAI 以外,Linear 創辦人 Karri Saarinen 亦指出,隨著我們發佈 Symphony,建立的工作區數量急升(在新視窗中開啟)。不過,更深層的轉變在於團隊如何思考工作。

當我們的工程師不再需要花時間監督 Codex 工作階段,程式碼變更的經濟效益就會徹底改變。每項變更的感知成本都會下降,因為我們不再需要投入人手推動實作本身。

這改變了我們的工作方式。在 Symphony 中啟動探索性任務變得非常簡單:嘗試一個構想、探索一次重構、測試一個假設,然後只保留看起來有潛力的結果。

這亦擴大了可以發起工作的參與者範圍。現在,我們的產品經理和設計師可以直接在 Symphony 中提交功能請求。他們毋須取出程式碼庫,也毋須管理 Codex 工作階段。只需描述功能,便會收到一份審查資料包,當中包括在實際產品中展示該功能運作的影片導覽。

Symphony 在大型單一程式碼庫中亦特別出色,例如 OpenAI 所使用的程式碼庫。對這類程式碼庫而言,PR 合併前的最後一步往往緩慢且脆弱。系統會監察 CI,在需要時重新變基、解決衝突、重試不穩定的檢查,並整體引導變更通過流程。當支援票證到達合併階段時,我們已高度相信該變更能夠在無需人手反覆跟進的情況下合併至主分支。

Before and after grid of Symphony

進展也會帶來截然不同的新問題

以這個層級運作會有取捨。當我們由互動式引導智能代理,轉為在支援票證層級分派工作時,我們失去了在執行途中持續輕推它們、並在需要時修正方向的能力。有時智能代理產出的結果會完全偏離目標。但這其實亦有作用,因為這些失敗暴露了系統中的缺口,也幫助我們令系統變得更穩健。

我們沒有手動修補結果,而是加入安全護欄和相關技能,讓智能代理在下一次能成功完成任務。隨著時間推移,我們為框架加入了新的能力,例如執行端到端測試、透過 Chrome DevTools 操控應用程式,以及管理 QA 冒煙測試。我們亦大幅改善了文件,並清楚界定何謂良好標準。

並非每項任務都適合 Symphony 這種工作方式。有些問題仍然需要工程師直接使用互動式 Codex 工作階段來處理,尤其是含糊的問題,或需要強判斷力和專業知識的工作。實際上,這些通常亦是我們工程師最感興趣、做起來最享受的任務。

不同之處在於,Symphony 可以處理大量常規實作工作。這讓工程師能夠一次專注於一個困難問題,而不是不斷在較小任務之間切換上下文。

我們亦發現,把智能代理視為狀態機中的固定節點,效果並不理想。模型變得越來越聰明,能夠解決的問題也比我們嘗試套用的框架更大。例如,早期版本把所有 GitHub 整合都放在外部框架內處理。早期版本預期 Codex 只負責修改程式碼,其餘流程(例如提交變更、執行測試)則由程式碼指定。我們最初的智能代理工作方式,只是要求 Codex 實作任務。事實證明,這種做法過於受限。Codex 完全有能力建立多個 PR,也能讀取審查意見並作出修正。因此,我們給它工具,例如 gh CLI、讀取 CI 記錄的技能等。現在,我們可以要求 Codex 做更多事情,例如關閉舊 PR,或拉取已完成與已放棄工作的報告。這類任務遠遠超出了最初「功能實作」的框架。

所以我們最終轉向給智能代理設定目標,而不是嚴格的狀態轉換,這很像一位好經理會向直屬下屬指派目標。模型的威力來自其推理能力,所以給它們工具和上下文,然後讓它們盡情發揮。

使用 Symphony 來打造 Symphony

當你打開 Symphony 程式碼庫時,首先會注意到,Symphony 在技術上其實只是一個 SPEC.md 檔案,亦即一份對問題和預期解決方案的定義。我們沒有建立一個複雜的監督系統,而是定義問題與預期解法,從而為智能代理提供高層次引導。

Markdown

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# Symphony Service Specification
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Status: Draft v1 (language-agnostic)
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Purpose: Define a service that orchestrates coding agents to get project work done.
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## 1. Problem Statement
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Symphony is a long-running automation service that continuously reads work from an issue tracker
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(Linear in this specification version), creates an isolated workspace for each issue, and runs a
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coding agent session for that issue inside the workspace.
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The service solves four operational problems:
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- It turns issue execution into a repeatable daemon workflow instead of manual scripts.
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- It isolates agent execution in per-issue workspaces so agent commands run only inside per-issue
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workspace directories.
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- It keeps the workflow policy in-repo (`WORKFLOW.md`) so teams version the agent prompt and runtime
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settings with their code.
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- It provides enough observability to operate and debug multiple concurrent agent runs.
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Implementations are expected to document their trust and safety posture explicitly. This
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specification does not require a single approval, sandbox, or operator-confirmation policy; some
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implementations may target trusted environments with a high-trust configuration, while others may
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require stricter approvals or sandboxing.
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Important boundary:
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- Symphony is a scheduler/runner and tracker reader.
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- Ticket writes (state transitions, comments, PR links) are typically performed by the coding agent
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using tools available in the workflow/runtime environment.
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- A successful run may end at a workflow-defined handoff state (for example `Human Review`), not
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necessarily `Done`.
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## 2. Goals and Non-Goals
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### 2.1 Goals
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- Poll the issue tracker on a fixed cadence and dispatch work with bounded concurrency.
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- Maintain a single authoritative orchestrator state for dispatch, retries, and reconciliation.
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- Create deterministic per-issue workspaces and preserve them across runs.
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- Stop active runs when issue state changes make them ineligible.
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- Recover from transient failures with exponential backoff.
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- Load runtime behavior from a repository-owned `WORKFLOW.md` contract.
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- Expose operator-visible observability (at minimum structured logs).
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- Support restart recovery without requiring a persistent database.
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### 2.2 Non-Goals
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- Rich web UI or multi-tenant control plane.
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- Prescribing a specific dashboard or terminal UI implementation.
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- General-purpose workflow engine or distributed job scheduler.
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- Built-in business logic for how to edit tickets, PRs, or comments. (That logic lives in the
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workflow prompt and agent tooling.)
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- Mandating strong sandbox controls beyond what the coding agent and host OS provide.
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- Mandating a single default approval, sandbox, or operator-confirmation posture for all
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implementations.
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## 3. System Overview
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### 3.1 Main Components
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1. `Workflow Loader`
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- Reads `WORKFLOW.md`.
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- Parses YAML front matter and prompt body.
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- Returns `{config, prompt_template}`.
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2. `Config Layer`
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- Exposes typed getters for workflow config values.
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- Applies defaults and environment variable indirection.
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- Performs validation used by the orchestrator before dispatch.
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3. `Issue Tracker Client`
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- Fetches candidate issues in active states.
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- Fetches current states for specific issue IDs (reconciliation).
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- Fetches terminal-state issues during startup cleanup.
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- Normalizes tracker payloads into a stable issue model.
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4. `Orchestrator`
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- Owns the poll tick.
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- Owns the in-memory runtime state.
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- Decides which issues to dispatch, retry, stop, or release.
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- Tracks session metrics and retry queue state.
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5. `Workspace Manager`
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- Maps issue identifiers to workspace paths.
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- Ensures per-issue workspace directories exist.
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- Runs workspace lifecycle hooks.
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- Cleans workspaces for terminal issues.
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6. `Agent Runner`
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- Creates workspace.
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- Builds prompt from issue + workflow template.
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- Launches the coding agent app-server client.
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- Streams agent updates back to the orchestrator.
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7. `Status Surface` (optional)
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- Presents human-readable runtime status (for example terminal output, dashboard, or other
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operator-facing view).
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8. `Logging`
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- Emits structured runtime logs to one or more configured sinks.
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### 3.2 Abstraction Levels
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Symphony is easiest to port when kept in these layers:
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1. `Policy Layer` (repo-defined)
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- `WORKFLOW.md` prompt body.
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- Team-specific rules for ticket handling, validation, and handoff.
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2. `Configuration Layer` (typed getters)
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- Parses front matter into typed runtime settings.
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- Handles defaults, environment tokens, and path normalization.
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3. `Coordination Layer` (orchestrator)
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- Polling loop, issue eligibility, concurrency, retries, reconciliation.
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4. `Execution Layer` (workspace + agent subprocess)
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- Filesystem lifecycle, workspace preparation, coding-agent protocol.
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5. `Integration Layer` (Linear adapter)
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- API calls and normalization for tracker data.
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6. `Observability Layer` (logs + optional status surface)
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- Operator visibility into orchestrator and agent behavior.
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### 3.3 External Dependencies
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- Issue tracker API (Linear for `tracker.kind: linear` in this specification version).
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- Local filesystem for workspaces and logs.
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- Optional workspace population tooling (for example Git CLI, if used).
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- Coding-agent executable that supports JSON-RPC-like app-server mode over stdio.
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- Host environment authentication for the issue tracker and coding agent.
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## 4. Core Domain Model
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### 4.1 Entities
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#### 4.1.1 Issue
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Normalized issue record used by orchestration, prompt rendering, and observability output.
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Fields:
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- `id` (string)
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- Stable tracker-internal ID.
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- `identifier` (string)
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- Human-readable ticket key (example: `ABC-123`).
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- `title` (string)
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- `description` (string or null)
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- `priority` (integer or null)
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- Lower numbers are higher priority in dispatch sorting.
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- `state` (string)
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- Current tracker state name.
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- `branch_name` (string or null)
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- Tracker-provided branch metadata if available.
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- `url` (string or null)
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- `labels` (list of strings)
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- Normalized to lowercase.
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- `blocked_by` (list of blocker refs)
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- Each blocker ref contains:
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- `id` (string or null)
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- `identifier` (string or null)
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- `state` (string or null)
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- `created_at` (timestamp or null)
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- `updated_at` (timestamp or null)
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#### 4.1.2 Workflow Definition
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Parsed `WORKFLOW.md` payload:
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- `config` (map)
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- YAML front matter root object.
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- `prompt_template` (string)
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- Markdown body after front matter, trimmed.
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#### 4.1.3 Service Config (Typed View)
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Typed runtime values derived from `WorkflowDefinition.config` plus environment resolution.
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Examples:
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- poll interval
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- workspace root
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- active and terminal issue states
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- concurrency limits
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- coding-agent executable/args/timeouts
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- workspace hooks
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#### 4.1.4 Workspace
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Filesystem workspace assigned to one issue identifier.
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Fields (logical):
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- `path` (workspace path; current runtime typically uses absolute paths, but relative roots are
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possible if configured without path separators)
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- `workspace_key` (sanitized issue identifier)
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- `created_now` (boolean, used to gate `after_create` hook)
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#### 4.1.5 Run Attempt
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One execution attempt for one issue.
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Fields (logical):
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- `issue_id`
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- `issue_identifier`
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- `attempt` (integer or null, `null` for first run, `>=1` for retries/continuation)
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- `workspace_path`
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- `started_at`
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- `status`
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- `error` (optional)
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#### 4.1.6 Live Session (Agent Session Metadata)
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State tracked while a coding-agent subprocess is running.
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Fields:
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- `session_id` (string, `<thread_id>-<turn_id>`)
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- `thread_id` (string)
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- `turn_id` (string)
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- `codex_app_server_pid` (string or null)
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- `last_codex_event` (string/enum or null)
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- `last_codex_timestamp` (timestamp or null)
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- `last_codex_message` (summarized payload)
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- `codex_input_tokens` (integer)
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- `codex_output_tokens` (integer)
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- `codex_total_tokens` (integer)
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- `last_reported_input_tokens` (integer)
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- `last_reported_output_tokens` (integer)
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- `last_reported_total_tokens` (integer)
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- `turn_count` (integer)
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- Number of coding-agent turns started within the current worker lifetime.
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#### 4.1.7 Retry Entry
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Scheduled retry state for an issue.
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Fields:
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- `issue_id`
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- `identifier` (best-effort human ID for status surfaces/logs)
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- `attempt` (integer, 1-based for retry queue)
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- `due_at_ms` (monotonic clock timestamp)
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- `timer_handle` (runtime-specific timer reference)
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- `error` (string or null)
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#### 4.1.8 Orchestrator Runtime State
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Single authoritative in-memory state owned by the orchestrator.
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Fields:
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- `poll_interval_ms` (current effective poll interval)
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- `max_concurrent_agents` (current effective global concurrency limit)
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- `running` (map `issue_id -> running entry`)
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- `claimed` (set of issue IDs reserved/running/retrying)
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- `retry_attempts` (map `issue_id -> RetryEntry`)
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- `completed` (set of issue IDs; bookkeeping only, not dispatch gating)
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- `codex_totals` (aggregate tokens + runtime seconds)
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- `codex_rate_limits` (latest rate-limit snapshot from agent events)
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### 4.2 Stable Identifiers and Normalization Rules
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- `Issue ID`
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- Use for tracker lookups and internal map keys.
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- `Issue Identifier`
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- Use for human-readable logs and workspace naming.
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- `Workspace Key`
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- Derive from `issue.identifier` by replacing any character not in `[A-Za-z0-9._-]` with `_`.
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- Use the sanitized value for the workspace directory name.
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- `Normalized Issue State`
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- Compare states after `lowercase`.
277
- `Session ID`
278
- Compose from coding-agent `thread_id` and `turn_id` as `<thread_id>-<turn_id>`.
279

280
## 5. Workflow Specification (Repository Contract)
281

282
### 5.1 File Discovery and Path Resolution
283

284
Workflow file path precedence:
285

286
1. Explicit application/runtime setting (set by CLI startup path).
287
2. Default: `WORKFLOW.md` in the current process working directory.
288

289
Loader behavior:
290

291
- If the file cannot be read, return `missing_workflow_file` error.
292
- The workflow file is expected to be repository-owned and version-controlled.
293

294
### 5.2 File Format
295

296
`WORKFLOW.md` is a Markdown file with optional YAML front matter.
297

298
Design note:
299

300
- `WORKFLOW.md` should be self-contained enough to describe and run different workflows (prompt,
301
runtime settings, hooks, and tracker selection/config) without requiring out-of-band
302
service-specific configuration.
303

304
Parsing rules:
305

306
- If file starts with `---`, parse lines until the next `---` as YAML front matter.
307
- Remaining lines become the prompt body.
308
- If front matter is absent, treat the entire file as prompt body and use an empty config map.
309
- YAML front matter must decode to a map/object; non-map YAML is an error.
310
- Prompt body is trimmed before use.
311

312
Returned workflow object:
313

314
- `config`: front matter root object (not nested under a `config` key).
315
- `prompt_template`: trimmed Markdown body.
316

317
### 5.3 Front Matter Schema
318

319
Top-level keys:
320

321
- `tracker`
322
- `polling`
323
- `workspace`
324
- `hooks`
325
- `agent`
326
- `codex`
327

328
Unknown keys should be ignored for forward compatibility.
329

330
Note:
331

332
- The workflow front matter is extensible. Optional extensions may define additional top-level keys
333
(for example `server`) without changing the core schema above.
334
- Extensions should document their field schema, defaults, validation rules, and whether changes
335
apply dynamically or require restart.
336
- Common extension: `server.port` (integer) enables the optional HTTP server described in Section
337
13.7.
338

339
#### 5.3.1 `tracker` (object)
340

341
Fields:
342

343
- `kind` (string)
344
- Required for dispatch.
345
- Current supported value: `linear`
346
- `endpoint` (string)
347
- Default for `tracker.kind == "linear"`: `https://api.linear.app/graphql`
348
- `api_key` (string)
349
- May be a literal token or `$VAR_NAME`.
350
- Canonical environment variable for `tracker.kind == "linear"`: `LINEAR_API_KEY`.
351
- If `$VAR_NAME` resolves to an empty string, treat the key as missing.
352
- `project_slug` (string)
353
- Required for dispatch when `tracker.kind == "linear"`.
354
- `active_states` (list of strings)
355
- Default: `Todo`, `In Progress`
356
- `terminal_states` (list of strings)
357
- Default: `Closed`, `Cancelled`, `Canceled`, `Duplicate`, `Done`
358

359
#### 5.3.2 `polling` (object)
360

361
Fields:
362

363
- `interval_ms` (integer or string integer)
364
- Default: `30000`
365
- Changes should be re-applied at runtime and affect future tick scheduling without restart.
366

367
#### 5.3.3 `workspace` (object)
368

369
Fields:
370

371
- `root` (path string or `$VAR`)
372
- Default: `<system-temp>/symphony_workspaces`
373
- `~` and strings containing path separators are expanded.
374
- Bare strings without path separators are preserved as-is (relative roots are allowed but
375
discouraged).
376
377
#### 5.3.4 `hooks` (object)
378

379
Fields:
380

381
- `after_create` (multiline shell script string, optional)
382
- Runs only when a workspace directory is newly created.
383
- Failure aborts workspace creation.
384
- `before_run` (multiline shell script string, optional)
385
- Runs before each agent attempt after workspace preparation and before launching the coding
386
agent.
387
- Failure aborts the current attempt.
388
- `after_run` (multiline shell script string, optional)
389
- Runs after each agent attempt (success, failure, timeout, or cancellation) once the workspace
390
exists.
391
- Failure is logged but ignored.
392
- `before_remove` (multiline shell script string, optional)
393
- Runs before workspace deletion if the directory exists.
394
- Failure is logged but ignored; cleanup still proceeds.
395
- `timeout_ms` (integer, optional)
396
- Default: `60000`
397
- Applies to all workspace hooks.
398
- Non-positive values should be treated as invalid and fall back to the default.
399
- Changes should be re-applied at runtime for future hook executions.
400
401
#### 5.3.5 `agent` (object)
402

403
Fields:
404

405
- `max_concurrent_agents` (integer or string integer)
406
- Default: `10`
407
- Changes should be re-applied at runtime and affect subsequent dispatch decisions.
408
- `max_retry_backoff_ms` (integer or string integer)
409
- Default: `300000` (5 minutes)
410
- Changes should be re-applied at runtime and affect future retry scheduling.
411
- `max_concurrent_agents_by_state` (map `state_name -> positive integer`)
412
- Default: empty map.
413
- State keys are normalized (`lowercase`) for lookup.
414
- Invalid entries (non-positive or non-numeric) are ignored.
415

416
#### 5.3.6 `codex` (object)
417

418
Fields:
419

420
For Codex-owned config values such as `approval_policy`, `thread_sandbox`, and
421
`turn_sandbox_policy`, supported values are defined by the targeted Codex app-server version.
422
Implementors should treat them as pass-through Codex config values rather than relying on a
423
hand-maintained enum in this spec. To inspect the installed Codex schema, run
424
`codex app-server generate-json-schema --out <dir>` and inspect the relevant definitions referenced
425
by `v2/ThreadStartParams.json` and `v2/TurnStartParams.json`. Implementations may validate these
426
fields locally if they want stricter startup checks.
427

428
- `command` (string shell command)
429
- Default: `codex app-server`
430
- The runtime launches this command via `bash -lc` in the workspace directory.
431
- The launched process must speak a compatible app-server protocol over stdio.
432
- `approval_policy` (Codex `AskForApproval` value)
433
- Default: implementation-defined.
434
- `thread_sandbox` (Codex `SandboxMode` value)
435
- Default: implementation-defined.
436
- `turn_sandbox_policy` (Codex `SandboxPolicy` value)
437
- Default: implementation-defined.
438
- `turn_timeout_ms` (integer)
439
- Default: `3600000` (1 hour)
440
- `read_timeout_ms` (integer)
441
- Default: `5000`
442
- `stall_timeout_ms` (integer)
443
- Default: `300000` (5 minutes)
444
- If `<= 0`, stall detection is disabled.
445

446
### 5.4 Prompt Template Contract
447

448
The Markdown body of `WORKFLOW.md` is the per-issue prompt template.
449

450
Rendering requirements:
451

452
- Use a strict template engine (Liquid-compatible semantics are sufficient).
453
- Unknown variables must fail rendering.
454
- Unknown filters must fail rendering.
455

456
Template input variables:
457

458
- `issue` (object)
459
- Includes all normalized issue fields, including labels and blockers.
460
- `attempt` (integer or null)
461
- `null`/absent on first attempt.
462
- Integer on retry or continuation run.
463

464
Fallback prompt behavior:
465

466
- If the workflow prompt body is empty, the runtime may use a minimal default prompt
467
(`You are working on an issue from Linear.`).
468
- Workflow file read/parse failures are configuration/validation errors and should not silently fall
469
back to a prompt.
470

471
### 5.5 Workflow Validation and Error Surface
472

473
Error classes:
474

475
- `missing_workflow_file`
476
- `workflow_parse_error`
477
- `workflow_front_matter_not_a_map`
478
- `template_parse_error` (during prompt rendering)
479
- `template_render_error` (unknown variable/filter, invalid interpolation)
480

481
Dispatch gating behavior:
482

483
- Workflow file read/YAML errors block new dispatches until fixed.
484
- Template errors fail only the affected run attempt.
485

486
## 6. Configuration Specification
487

488
### 6.1 Source Precedence and Resolution Semantics
489

490
Configuration precedence:
491

492
1. Workflow file path selection (runtime setting -> cwd default).
493
2. YAML front matter values.
494
3. Environment indirection via `$VAR_NAME` inside selected YAML values.
495
4. Built-in defaults.
496

497
Value coercion semantics:
498

499
- Path/command fields support:
500
- `~` home expansion
501
- `$VAR` expansion for env-backed path values
502
- Apply expansion only to values intended to be local filesystem paths; do not rewrite URIs or
503
arbitrary shell command strings.
504
505
### 6.2 Dynamic Reload Semantics
506

507
Dynamic reload is required:
508

509
- The software should watch `WORKFLOW.md` for changes.
510
- On change, it should re-read and re-apply workflow config and prompt template without restart.
511
- The software should attempt to adjust live behavior to the new config (for example polling
512
cadence, concurrency limits, active/terminal states, codex settings, workspace paths/hooks, and
513
prompt content for future runs).
514
- Reloaded config applies to future dispatch, retry scheduling, reconciliation decisions, hook
515
execution, and agent launches.
516
- Implementations are not required to restart in-flight agent sessions automatically when config
517
changes.
518
- Extensions that manage their own listeners/resources (for example an HTTP server port change) may
519
require restart unless the implementation explicitly supports live rebind.
520
- Implementations should also re-validate/reload defensively during runtime operations (for example
521
before dispatch) in case filesystem watch events are missed.
522
- Invalid reloads should not crash the service; keep operating with the last known good effective
523
configuration and emit an operator-visible error.
524

525
### 6.3 Dispatch Preflight Validation
526

527
This validation is a scheduler preflight run before attempting to dispatch new work. It validates
528
the workflow/config needed to poll and launch workers, not a full audit of all possible workflow
529
behavior.
530

531
Startup validation:
532

533
- Validate configuration before starting the scheduling loop.
534
- If startup validation fails, fail startup and emit an operator-visible error.
535

536
Per-tick dispatch validation:
537

538
- Re-validate before each dispatch cycle.
539
- If validation fails, skip dispatch for that tick, keep reconciliation active, and emit an
540
operator-visible error.
541

542
Validation checks:
543

544
- Workflow file can be loaded and parsed.
545
- `tracker.kind` is present and supported.
546
- `tracker.api_key` is present after `$` resolution.
547
- `tracker.project_slug` is present when required by the selected tracker kind.
548
- `codex.command` is present and non-empty.
549

550
### 6.4 Config Fields Summary (Cheat Sheet)
551

552
This section is intentionally redundant so a coding agent can implement the config layer quickly.
553

554
- `tracker.kind`: string, required, currently `linear`
555
- `tracker.endpoint`: string, default `https://api.linear.app/graphql` when `tracker.kind=linear`
556
- `tracker.api_key`: string or `$VAR`, canonical env `LINEAR_API_KEY` when `tracker.kind=linear`
557
- `tracker.project_slug`: string, required when `tracker.kind=linear`
558
- `tracker.active_states`: list of strings, default `["Todo", "In Progress"]`
559
- `tracker.terminal_states`: list of strings, default `["Closed", "Cancelled", "Canceled", "Duplicate", "Done"]`
560
- `polling.interval_ms`: integer, default `30000`
561
- `workspace.root`: path, default `<system-temp>/symphony_workspaces`
562
- `worker.ssh_hosts` (extension): list of SSH host strings, optional; when omitted, work runs
563
locally
564
- `worker.max_concurrent_agents_per_host` (extension): positive integer, optional; shared per-host
565
cap applied across configured SSH hosts
566
- `hooks.after_create`: shell script or null
567
- `hooks.before_run`: shell script or null
568
- `hooks.after_run`: shell script or null
569
- `hooks.before_remove`: shell script or null
570
- `hooks.timeout_ms`: integer, default `60000`
571
- `agent.max_concurrent_agents`: integer, default `10`
572
- `agent.max_turns`: integer, default `20`
573
- `agent.max_retry_backoff_ms`: integer, default `300000` (5m)
574
- `agent.max_concurrent_agents_by_state`: map of positive integers, default `{}`
575
- `codex.command`: shell command string, default `codex app-server`
576
- `codex.approval_policy`: Codex `AskForApproval` value, default implementation-defined
577
- `codex.thread_sandbox`: Codex `SandboxMode` value, default implementation-defined
578
- `codex.turn_sandbox_policy`: Codex `SandboxPolicy` value, default implementation-defined
579
- `codex.turn_timeout_ms`: integer, default `3600000`
580
- `codex.read_timeout_ms`: integer, default `5000`
581
- `codex.stall_timeout_ms`: integer, default `300000`
582
- `server.port` (extension): integer, optional; enables the optional HTTP server, `0` may be used
583
for ephemeral local bind, and CLI `--port` overrides it
584

585
## 7. Orchestration State Machine
586

587
The orchestrator is the only component that mutates scheduling state. All worker outcomes are
588
reported back to it and converted into explicit state transitions.
589

590
### 7.1 Issue Orchestration States
591

592
This is not the same as tracker states (`Todo`, `In Progress`, etc.). This is the service's internal
593
claim state.
594

595
1. `Unclaimed`
596
- Issue is not running and has no retry scheduled.
597

598
2. `Claimed`
599
- Orchestrator has reserved the issue to prevent duplicate dispatch.
600
- In practice, claimed issues are either `Running` or `RetryQueued`.
601

602
3. `Running`
603
- Worker task exists and the issue is tracked in `running` map.
604

605
4. `RetryQueued`
606
- Worker is not running, but a retry timer exists in `retry_attempts`.
607

608
5. `Released`
609
- Claim removed because issue is terminal, non-active, missing, or retry path completed without
610
re-dispatch.
611
612
Important nuance:
613

614
- A successful worker exit does not mean the issue is done forever.
615
- The worker may continue through multiple back-to-back coding-agent turns before it exits.
616
- After each normal turn completion, the worker re-checks the tracker issue state.
617
- If the issue is still in an active state, the worker should start another turn on the same live
618
coding-agent thread in the same workspace, up to `agent.max_turns`.
619
- The first turn should use the full rendered task prompt.
620
- Continuation turns should send only continuation guidance to the existing thread, not resend the
621
original task prompt that is already present in thread history.
622
- Once the worker exits normally, the orchestrator still schedules a short continuation retry
623
(about 1 second) so it can re-check whether the issue remains active and needs another worker
624
session.
625

626
### 7.2 Run Attempt Lifecycle
627

628
A run attempt transitions through these phases:
629

630
1. `PreparingWorkspace`
631
2. `BuildingPrompt`
632
3. `LaunchingAgentProcess`
633
4. `InitializingSession`
634
5. `StreamingTurn`
635
6. `Finishing`
636
7. `Succeeded`
637
8. `Failed`
638
9. `TimedOut`
639
10. `Stalled`
640
11. `CanceledByReconciliation`
641

642
Distinct terminal reasons are important because retry logic and logs differ.
643

644
### 7.3 Transition Triggers
645

646
- `Poll Tick`
647
- Reconcile active runs.
648
- Validate config.
649
- Fetch candidate issues.
650
- Dispatch until slots are exhausted.
651

652
- `Worker Exit (normal)`
653
- Remove running entry.
654
- Update aggregate runtime totals.
655
- Schedule continuation retry (attempt `1`) after the worker exhausts or finishes its in-process
656
turn loop.
657
658
- `Worker Exit (abnormal)`
659
- Remove running entry.
660
- Update aggregate runtime totals.
661
- Schedule exponential-backoff retry.
662

663
- `Codex Update Event`
664
- Update live session fields, token counters, and rate limits.
665

666
- `Retry Timer Fired`
667
- Re-fetch active candidates and attempt re-dispatch, or release claim if no longer eligible.
668

669
- `Reconciliation State Refresh`
670
- Stop runs whose issue states are terminal or no longer active.
671

672
- `Stall Timeout`
673
- Kill worker and schedule retry.
674

675
### 7.4 Idempotency and Recovery Rules
676

677
- The orchestrator serializes state mutations through one authority to avoid duplicate dispatch.
678
- `claimed` and `running` checks are required before launching any worker.
679
- Reconciliation runs before dispatch on every tick.
680
- Restart recovery is tracker-driven and filesystem-driven (no durable orchestrator DB required).
681
- Startup terminal cleanup removes stale workspaces for issues already in terminal states.
682

683
## 8. Polling, Scheduling, and Reconciliation
684

685
### 8.1 Poll Loop
686

687
At startup, the service validates config, performs startup cleanup, schedules an immediate tick, and
688
then repeats every `polling.interval_ms`.
689

690
The effective poll interval should be updated when workflow config changes are re-applied.
691

692
Tick sequence:
693

694
1. Reconcile running issues.
695
2. Run dispatch preflight validation.
696
3. Fetch candidate issues from tracker using active states.
697
4. Sort issues by dispatch priority.
698
5. Dispatch eligible issues while slots remain.
699
6. Notify observability/status consumers of state changes.
700

701
If per-tick validation fails, dispatch is skipped for that tick, but reconciliation still happens
702
first.
703

704
### 8.2 Candidate Selection Rules
705

706
An issue is dispatch-eligible only if all are true:
707

708
- It has `id`, `identifier`, `title`, and `state`.
709
- Its state is in `active_states` and not in `terminal_states`.
710
- It is not already in `running`.
711
- It is not already in `claimed`.
712
- Global concurrency slots are available.
713
- Per-state concurrency slots are available.
714
- Blocker rule for `Todo` state passes:
715
- If the issue state is `Todo`, do not dispatch when any blocker is non-terminal.
716

717
Sorting order (stable intent):
718

719
1. `priority` ascending (1..4 are preferred; null/unknown sorts last)
720
2. `created_at` oldest first
721
3. `identifier` lexicographic tie-breaker
722

723
### 8.3 Concurrency Control
724

725
Global limit:
726

727
- `available_slots = max(max_concurrent_agents - running_count, 0)`
728

729
Per-state limit:
730

731
- `max_concurrent_agents_by_state[state]` if present (state key normalized)
732
- otherwise fallback to global limit
733

734
The runtime counts issues by their current tracked state in the `running` map.
735

736
Optional SSH host limit:
737

738
- When `worker.max_concurrent_agents_per_host` is set, each configured SSH host may run at most
739
that many concurrent agents at once.
740
- Hosts at that cap are skipped for new dispatch until capacity frees up.
741

742
### 8.4 Retry and Backoff
743

744
Retry entry creation:
745

746
- Cancel any existing retry timer for the same issue.
747
- Store `attempt`, `identifier`, `error`, `due_at_ms`, and new timer handle.
748

749
Backoff formula:
750

751
- Normal continuation retries after a clean worker exit use a short fixed delay of `1000` ms.
752
- Failure-driven retries use `delay = min(10000 * 2^(attempt - 1), agent.max_retry_backoff_ms)`.
753
- Power is capped by the configured max retry backoff (default `300000` / 5m).
754

755
Retry handling behavior:
756

757
1. Fetch active candidate issues (not all issues).
758
2. Find the specific issue by `issue_id`.
759
3. If not found, release claim.
760
4. If found and still candidate-eligible:
761
- Dispatch if slots are available.
762
- Otherwise requeue with error `no available orchestrator slots`.
763
5. If found but no longer active, release claim.
764

765
Note:
766

767
- Terminal-state workspace cleanup is handled by startup cleanup and active-run reconciliation
768
(including terminal transitions for currently running issues).
769
- Retry handling mainly operates on active candidates and releases claims when the issue is absent,
770
rather than performing terminal cleanup itself.
771

772
### 8.5 Active Run Reconciliation
773

774
Reconciliation runs every tick and has two parts.
775

776
Part A: Stall detection
777

778
- For each running issue, compute `elapsed_ms` since:
779
- `last_codex_timestamp` if any event has been seen, else
780
- `started_at`
781
- If `elapsed_ms > codex.stall_timeout_ms`, terminate the worker and queue a retry.
782
- If `stall_timeout_ms <= 0`, skip stall detection entirely.
783

784
Part B: Tracker state refresh
785

786
- Fetch current issue states for all running issue IDs.
787
- For each running issue:
788
- If tracker state is terminal: terminate worker and clean workspace.
789
- If tracker state is still active: update the in-memory issue snapshot.
790
- If tracker state is neither active nor terminal: terminate worker without workspace cleanup.
791
- If state refresh fails, keep workers running and try again on the next tick.
792

793
### 8.6 Startup Terminal Workspace Cleanup
794

795
When the service starts:
796

797
1. Query tracker for issues in terminal states.
798
2. For each returned issue identifier, remove the corresponding workspace directory.
799
3. If the terminal-issues fetch fails, log a warning and continue startup.
800

801
This prevents stale terminal workspaces from accumulating after restarts.
802

803
## 9. Workspace Management and Safety
804

805
### 9.1 Workspace Layout
806

807
Workspace root:
808

809
- `workspace.root` (normalized path; the current config layer expands path-like values and preserves
810
bare relative names)
811

812
Per-issue workspace path:
813

814
- `<workspace.root>/<sanitized_issue_identifier>`
815

816
Workspace persistence:
817

818
- Workspaces are reused across runs for the same issue.
819
- Successful runs do not auto-delete workspaces.
820

821
### 9.2 Workspace Creation and Reuse
822

823
Input: `issue.identifier`
824

825
Algorithm summary:
826

827
1. Sanitize identifier to `workspace_key`.
828
2. Compute workspace path under workspace root.
829
3. Ensure the workspace path exists as a directory.
830
4. Mark `created_now=true` only if the directory was created during this call; otherwise
831
`created_now=false`.
832
5. If `created_now=true`, run `after_create` hook if configured.
833

834
Notes:
835

836
- This section does not assume any specific repository/VCS workflow.
837
- Workspace preparation beyond directory creation (for example dependency bootstrap, checkout/sync,
838
code generation) is implementation-defined and is typically handled via hooks.
839

840
### 9.3 Optional Workspace Population (Implementation-Defined)
841

842
The spec does not require any built-in VCS or repository bootstrap behavior.
843

844
Implementations may populate or synchronize the workspace using implementation-defined logic and/or
845
hooks (for example `after_create` and/or `before_run`).
846

847
Failure handling:
848

849
- Workspace population/synchronization failures return an error for the current attempt.
850
- If failure happens while creating a brand-new workspace, implementations may remove the partially
851
prepared directory.
852
- Reused workspaces should not be destructively reset on population failure unless that policy is
853
explicitly chosen and documented.
854

855
### 9.4 Workspace Hooks
856

857
Supported hooks:
858

859
- `hooks.after_create`
860
- `hooks.before_run`
861
- `hooks.after_run`
862
- `hooks.before_remove`
863

864
Execution contract:
865

866
- Execute in a local shell context appropriate to the host OS, with the workspace directory as
867
`cwd`.
868
- On POSIX systems, `sh -lc <script>` (or a stricter equivalent such as `bash -lc <script>`) is a
869
conforming default.
870
- Hook timeout uses `hooks.timeout_ms`; default: `60000 ms`.
871
- Log hook start, failures, and timeouts.
872

873
Failure semantics:
874

875
- `after_create` failure or timeout is fatal to workspace creation.
876
- `before_run` failure or timeout is fatal to the current run attempt.
877
- `after_run` failure or timeout is logged and ignored.
878
- `before_remove` failure or timeout is logged and ignored.
879

880
### 9.5 Safety Invariants
881

882
This is the most important portability constraint.
883

884
Invariant 1: Run the coding agent only in the per-issue workspace path.
885

886
- Before launching the coding-agent subprocess, validate:
887
- `cwd == workspace_path`
888

889
Invariant 2: Workspace path must stay inside workspace root.
890

891
- Normalize both paths to absolute.
892
- Require `workspace_path` to have `workspace_root` as a prefix directory.
893
- Reject any path outside the workspace root.
894

895
Invariant 3: Workspace key is sanitized.
896

897
- Only `[A-Za-z0-9._-]` allowed in workspace directory names.
898
- Replace all other characters with `_`.
899

900
## 10. Agent Runner Protocol (Coding Agent Integration)
901

902
This section defines the language-neutral contract for integrating a coding agent app-server.
903

904
Compatibility profile:
905

906
- The normative contract is message ordering, required behaviors, and the logical fields that must
907
be extracted (for example session IDs, completion state, approval handling, and usage/rate-limit
908
telemetry).
909
- Exact JSON field names may vary slightly across compatible app-server versions.
910
- Implementations should tolerate equivalent payload shapes when they carry the same logical
911
meaning, especially for nested IDs, approval requests, user-input-required signals, and
912
token/rate-limit metadata.
913

914
### 10.1 Launch Contract
915

916
Subprocess launch parameters:
917

918
- Command: `codex.command`
919
- Invocation: `bash -lc <codex.command>`
920
- Working directory: workspace path
921
- Stdout/stderr: separate streams
922
- Framing: line-delimited protocol messages on stdout (JSON-RPC-like JSON per line)
923

924
Notes:
925

926
- The default command is `codex app-server`.
927
- Approval policy, cwd, and prompt are expressed in the protocol messages in Section 10.2.
928

929
Recommended additional process settings:
930

931
- Max line size: 10 MB (for safe buffering)
932

933
### 10.2 Session Startup Handshake
934

935
Reference: https://developers.openai.com/codex/app-server/
936

937
The client must send these protocol messages in order:
938

939
Illustrative startup transcript (equivalent payload shapes are acceptable if they preserve the same
940
semantics):
941

942
```json
943
{"id":1,"method":"initialize","params":{"clientInfo":{"name":"symphony","version":"1.0"},"capabilities":{}}}
944
{"method":"initialized","params":{}}
945
{"id":2,"method":"thread/start","params":{"approvalPolicy":"<implementation-defined>","sandbox":"<implementation-defined>","cwd":"/abs/workspace"}}
946
{"id":3,"method":"turn/start","params":{"threadId":"<thread-id>","input":[{"type":"text","text":"<rendered prompt-or-continuation-guidance>"}],"cwd":"/abs/workspace","title":"ABC-123: Example","approvalPolicy":"<implementation-defined>","sandboxPolicy":{"type":"<implementation-defined>"}}}
947
```
948

949
1. `initialize` request
950
- Params include:
951
- `clientInfo` object (for example `{name, version}`)
952
- `capabilities` object (may be empty)
953
- If the targeted Codex app-server requires capability negotiation for dynamic tools, include the
954
necessary capability flag(s) here.
955
- Wait for response (`read_timeout_ms`)
956
2. `initialized` notification
957
3. `thread/start` request
958
- Params include:
959
- `approvalPolicy` = implementation-defined session approval policy value
960
- `sandbox` = implementation-defined session sandbox value
961
- `cwd` = absolute workspace path
962
- If optional client-side tools are implemented, include their advertised tool specs using the
963
protocol mechanism supported by the targeted Codex app-server version.
964
4. `turn/start` request
965
- Params include:
966
- `threadId`
967
- `input` = single text item containing rendered prompt for the first turn, or continuation
968
guidance for later turns on the same thread
969
- `cwd`
970
- `title` = `<issue.identifier>: <issue.title>`
971
- `approvalPolicy` = implementation-defined turn approval policy value
972
- `sandboxPolicy` = implementation-defined object-form sandbox policy payload when required by
973
the targeted app-server version
974
975
Session identifiers:
976

977
- Read `thread_id` from `thread/start` result `result.thread.id`
978
- Read `turn_id` from each `turn/start` result `result.turn.id`
979
- Emit `session_id = "<thread_id>-<turn_id>"`
980
- Reuse the same `thread_id` for all continuation turns inside one worker run
981

982
### 10.3 Streaming Turn Processing
983

984
The client reads line-delimited messages until the turn terminates.
985

986
Completion conditions:
987

988
- `turn/completed` -> success
989
- `turn/failed` -> failure
990
- `turn/cancelled` -> failure
991
- turn timeout (`turn_timeout_ms`) -> failure
992
- subprocess exit -> failure
993

994
Continuation processing:
995

996
- If the worker decides to continue after a successful turn, it should issue another `turn/start`
997
on the same live `threadId`.
998
- The app-server subprocess should remain alive across those continuation turns and be stopped only
999
when the worker run is ending.
1000

1001
Line handling requirements:
1002

1003
- Read protocol messages from stdout only.
1004
- Buffer partial stdout lines until newline arrives.
1005
- Attempt JSON parse on complete stdout lines.
1006
- Stderr is not part of the protocol stream:
1007
- ignore it or log it as diagnostics
1008
- do not attempt protocol JSON parsing on stderr
1009

1010
### 10.4 Emitted Runtime Events (Upstream to Orchestrator)
1011

1012
The app-server client emits structured events to the orchestrator callback. Each event should
1013
include:
1014

1015
- `event` (enum/string)
1016
- `timestamp` (UTC timestamp)
1017
- `codex_app_server_pid` (if available)
1018
- optional `usage` map (token counts)
1019
- payload fields as needed
1020

1021
Important emitted events may include:
1022

1023
- `session_started`
1024
- `startup_failed`
1025
- `turn_completed`
1026
- `turn_failed`
1027
- `turn_cancelled`
1028
- `turn_ended_with_error`
1029
- `turn_input_required`
1030
- `approval_auto_approved`
1031
- `unsupported_tool_call`
1032
- `notification`
1033
- `other_message`
1034
- `malformed`
1035

1036
### 10.5 Approval, Tool Calls, and User Input Policy
1037

1038
Approval, sandbox, and user-input behavior is implementation-defined.
1039

1040
Policy requirements:
1041

1042
- Each implementation should document its chosen approval, sandbox, and operator-confirmation
1043
posture.
1044
- Approval requests and user-input-required events must not leave a run stalled indefinitely. An
1045
implementation should either satisfy them, surface them to an operator, auto-resolve them, or
1046
fail the run according to its documented policy.
1047

1048
Example high-trust behavior:
1049

1050
- Auto-approve command execution approvals for the session.
1051
- Auto-approve file-change approvals for the session.
1052
- Treat user-input-required turns as hard failure.
1053

1054
Unsupported dynamic tool calls:
1055

1056
- Supported dynamic tool calls that are explicitly implemented and advertised by the runtime should
1057
be handled according to their extension contract.
1058
- If the agent requests a dynamic tool call (`item/tool/call`) that is not supported, return a tool
1059
failure response and continue the session.
1060
- This prevents the session from stalling on unsupported tool execution paths.
1061

1062
Optional client-side tool extension:
1063

1064
- An implementation may expose a limited set of client-side tools to the app-server session.
1065
- Current optional standardized tool: `linear_graphql`.
1066
- If implemented, supported tools should be advertised to the app-server session during startup
1067
using the protocol mechanism supported by the targeted Codex app-server version.
1068
- Unsupported tool names should still return a failure result and continue the session.
1069

1070
`linear_graphql` extension contract:
1071

1072
- Purpose: execute a raw GraphQL query or mutation against Linear using Symphony's configured
1073
tracker auth for the current session.
1074
- Availability: only meaningful when `tracker.kind == "linear"` and valid Linear auth is configured.
1075
- Preferred input shape:
1076

1077
```json
1078
{
1079
"query": "single GraphQL query or mutation document",
1080
"variables": {
1081
"optional": "graphql variables object"
1082
}
1083
}
1084
```
1085

1086
- `query` must be a non-empty string.
1087
- `query` must contain exactly one GraphQL operation.
1088
- `variables` is optional and, when present, must be a JSON object.
1089
- Implementations may additionally accept a raw GraphQL query string as shorthand input.
1090
- Execute one GraphQL operation per tool call.
1091
- If the provided document contains multiple operations, reject the tool call as invalid input.
1092
- `operationName` selection is intentionally out of scope for this extension.
1093
- Reuse the configured Linear endpoint and auth from the active Symphony workflow/runtime config; do
1094
not require the coding agent to read raw tokens from disk.
1095
- Tool result semantics:
1096
- transport success + no top-level GraphQL `errors` -> `success=true`
1097
- top-level GraphQL `errors` present -> `success=false`, but preserve the GraphQL response body
1098
for debugging
1099
- invalid input, missing auth, or transport failure -> `success=false` with an error payload
1100
- Return the GraphQL response or error payload as structured tool output that the model can inspect
1101
in-session.
1102
1103
Illustrative responses (equivalent payload shapes are acceptable if they preserve the same outcome):
1104

1105
```json
1106
{"id":"<approval-id>","result":{"approved":true}}
1107
{"id":"<tool-call-id>","result":{"success":false,"error":"unsupported_tool_call"}}
1108
```
1109

1110
Hard failure on user input requirement:
1111

1112
- If the agent requests user input, fail the run attempt immediately.
1113
- The client detects this via:
1114
- explicit method (`item/tool/requestUserInput`), or
1115
- turn methods/flags indicating input is required.
1116

1117
### 10.6 Timeouts and Error Mapping
1118

1119
Timeouts:
1120

1121
- `codex.read_timeout_ms`: request/response timeout during startup and sync requests
1122
- `codex.turn_timeout_ms`: total turn stream timeout
1123
- `codex.stall_timeout_ms`: enforced by orchestrator based on event inactivity
1124

1125
Error mapping (recommended normalized categories):
1126

1127
- `codex_not_found`
1128
- `invalid_workspace_cwd`
1129
- `response_timeout`
1130
- `turn_timeout`
1131
- `port_exit`
1132
- `response_error`
1133
- `turn_failed`
1134
- `turn_cancelled`
1135
- `turn_input_required`
1136

1137
### 10.7 Agent Runner Contract
1138

1139
The `Agent Runner` wraps workspace + prompt + app-server client.
1140

1141
Behavior:
1142

1143
1. Create/reuse workspace for issue.
1144
2. Build prompt from workflow template.
1145
3. Start app-server session.
1146
4. Forward app-server events to orchestrator.
1147
5. On any error, fail the worker attempt (the orchestrator will retry).
1148

1149
Note:
1150

1151
- Workspaces are intentionally preserved after successful runs.
1152

1153
## 11. Issue Tracker Integration Contract (Linear-Compatible)
1154

1155
### 11.1 Required Operations
1156

1157
An implementation must support these tracker adapter operations:
1158

1159
1. `fetch_candidate_issues()`
1160
- Return issues in configured active states for a configured project.
1161

1162
2. `fetch_issues_by_states(state_names)`
1163
- Used for startup terminal cleanup.
1164

1165
3. `fetch_issue_states_by_ids(issue_ids)`
1166
- Used for active-run reconciliation.
1167

1168
### 11.2 Query Semantics (Linear)
1169

1170
Linear-specific requirements for `tracker.kind == "linear"`:
1171

1172
- `tracker.kind == "linear"`
1173
- GraphQL endpoint (default `https://api.linear.app/graphql`)
1174
- Auth token sent in `Authorization` header
1175
- `tracker.project_slug` maps to Linear project `slugId`
1176
- Candidate issue query filters project using `project: { slugId: { eq: $projectSlug } }`
1177
- Issue-state refresh query uses GraphQL issue IDs with variable type `[ID!]`
1178
- Pagination required for candidate issues
1179
- Page size default: `50`
1180
- Network timeout: `30000 ms`
1181

1182
Important:
1183

1184
- Linear GraphQL schema details can drift. Keep query construction isolated and test the exact query
1185
fields/types required by this specification.
1186

1187
A non-Linear implementation may change transport details, but the normalized outputs must match the
1188
domain model in Section 4.
1189

1190
### 11.3 Normalization Rules
1191

1192
Candidate issue normalization should produce fields listed in Section 4.1.1.
1193

1194
Additional normalization details:
1195

1196
- `labels` -> lowercase strings
1197
- `blocked_by` -> derived from inverse relations where relation type is `blocks`
1198
- `priority` -> integer only (non-integers become null)
1199
- `created_at` and `updated_at` -> parse ISO-8601 timestamps
1200

1201
### 11.4 Error Handling Contract
1202

1203
Recommended error categories:
1204

1205
- `unsupported_tracker_kind`
1206
- `missing_tracker_api_key`
1207
- `missing_tracker_project_slug`
1208
- `linear_api_request` (transport failures)
1209
- `linear_api_status` (non-200 HTTP)
1210
- `linear_graphql_errors`
1211
- `linear_unknown_payload`
1212
- `linear_missing_end_cursor` (pagination integrity error)
1213

1214
Orchestrator behavior on tracker errors:
1215

1216
- Candidate fetch failure: log and skip dispatch for this tick.
1217
- Running-state refresh failure: log and keep active workers running.
1218
- Startup terminal cleanup failure: log warning and continue startup.
1219

1220
### 11.5 Tracker Writes (Important Boundary)
1221

1222
Symphony does not require first-class tracker write APIs in the orchestrator.
1223

1224
- Ticket mutations (state transitions, comments, PR metadata) are typically handled by the coding
1225
agent using tools defined by the workflow prompt.
1226
- The service remains a scheduler/runner and tracker reader.
1227
- Workflow-specific success often means "reached the next handoff state" (for example
1228
`Human Review`) rather than tracker terminal state `Done`.
1229
- If the optional `linear_graphql` client-side tool extension is implemented, it is still part of
1230
the agent toolchain rather than orchestrator business logic.
1231

1232
## 12. Prompt Construction and Context Assembly
1233

1234
### 12.1 Inputs
1235

1236
Inputs to prompt rendering:
1237

1238
- `workflow.prompt_template`
1239
- normalized `issue` object
1240
- optional `attempt` integer (retry/continuation metadata)
1241

1242
### 12.2 Rendering Rules
1243

1244
- Render with strict variable checking.
1245
- Render with strict filter checking.
1246
- Convert issue object keys to strings for template compatibility.
1247
- Preserve nested arrays/maps (labels, blockers) so templates can iterate.
1248

1249
### 12.3 Retry/Continuation Semantics
1250

1251
`attempt` should be passed to the template because the workflow prompt may provide different
1252
instructions for:
1253

1254
- first run (`attempt` null or absent)
1255
- continuation run after a successful prior session
1256
- retry after error/timeout/stall
1257

1258
### 12.4 Failure Semantics
1259

1260
If prompt rendering fails:
1261

1262
- Fail the run attempt immediately.
1263
- Let the orchestrator treat it like any other worker failure and decide retry behavior.
1264

1265
## 13. Logging, Status, and Observability
1266

1267
### 13.1 Logging Conventions
1268

1269
Required context fields for issue-related logs:
1270

1271
- `issue_id`
1272
- `issue_identifier`
1273

1274
Required context for coding-agent session lifecycle logs:
1275

1276
- `session_id`
1277

1278
Message formatting requirements:
1279

1280
- Use stable `key=value` phrasing.
1281
- Include action outcome (`completed`, `failed`, `retrying`, etc.).
1282
- Include concise failure reason when present.
1283
- Avoid logging large raw payloads unless necessary.
1284

1285
### 13.2 Logging Outputs and Sinks
1286

1287
The spec does not prescribe where logs must go (stderr, file, remote sink, etc.).
1288

1289
Requirements:
1290

1291
- Operators must be able to see startup/validation/dispatch failures without attaching a debugger.
1292
- Implementations may write to one or more sinks.
1293
- If a configured log sink fails, the service should continue running when possible and emit an
1294
operator-visible warning through any remaining sink.
1295

1296
### 13.3 Runtime Snapshot / Monitoring Interface (Optional but Recommended)
1297

1298
If the implementation exposes a synchronous runtime snapshot (for dashboards or monitoring), it
1299
should return:
1300

1301
- `running` (list of running session rows)
1302
- each running row should include `turn_count`
1303
- `retrying` (list of retry queue rows)
1304
- `codex_totals`
1305
- `input_tokens`
1306
- `output_tokens`
1307
- `total_tokens`
1308
- `seconds_running` (aggregate runtime seconds as of snapshot time, including active sessions)
1309
- `rate_limits` (latest coding-agent rate limit payload, if available)
1310

1311
Recommended snapshot error modes:
1312

1313
- `timeout`
1314
- `unavailable`
1315

1316
### 13.4 Optional Human-Readable Status Surface
1317

1318
A human-readable status surface (terminal output, dashboard, etc.) is optional and
1319
implementation-defined.
1320

1321
If present, it should draw from orchestrator state/metrics only and must not be required for
1322
correctness.
1323

1324
### 13.5 Session Metrics and Token Accounting
1325

1326
Token accounting rules:
1327

1328
- Agent events may include token counts in multiple payload shapes.
1329
- Prefer absolute thread totals when available, such as:
1330
- `thread/tokenUsage/updated` payloads
1331
- `total_token_usage` within token-count wrapper events
1332
- Ignore delta-style payloads such as `last_token_usage` for dashboard/API totals.
1333
- Extract input/output/total token counts leniently from common field names within the selected
1334
payload.
1335
- For absolute totals, track deltas relative to last reported totals to avoid double-counting.
1336
- Do not treat generic `usage` maps as cumulative totals unless the event type defines them that
1337
way.
1338
- Accumulate aggregate totals in orchestrator state.
1339

1340
Runtime accounting:
1341

1342
- Runtime should be reported as a live aggregate at snapshot/render time.
1343
- Implementations may maintain a cumulative counter for ended sessions and add active-session
1344
elapsed time derived from `running` entries (for example `started_at`) when producing a
1345
snapshot/status view.
1346
- Add run duration seconds to the cumulative ended-session runtime when a session ends (normal exit
1347
or cancellation/termination).
1348
- Continuous background ticking of runtime totals is not required.
1349

1350
Rate-limit tracking:
1351

1352
- Track the latest rate-limit payload seen in any agent update.
1353
- Any human-readable presentation of rate-limit data is implementation-defined.
1354

1355
### 13.6 Humanized Agent Event Summaries (Optional)
1356

1357
Humanized summaries of raw agent protocol events are optional.
1358

1359
If implemented:
1360

1361
- Treat them as observability-only output.
1362
- Do not make orchestrator logic depend on humanized strings.
1363

參考實作以 Elixir 編寫,因為當程式碼幾乎免費時,你終於可以按語言本身的優勢作選擇,例如 Elixir 的並行處理能力。不過,核心概念可以用一份簡單的 Markdown 文件表達。我們鼓勵你讓你常用的編碼智能代理參考規格,並實作自己的版本。

Symphony 的第一個版本只是一個在 tmux 中運行的 Codex 工作階段,輪詢 Linear,並為新任務啟動子智能代理。它是可行的,但不算特別可靠。第二個版本則放在我們主要的項目程式碼庫中,而那個程式碼庫本來就是以智能代理為中心打造。我們早已建立智能代理框架,讓智能代理具備在這個程式碼庫中完成高質素工作的技能和上下文;因此,Symphony 只是把這一切連接起來。

當基本功能具備後,我們就用 Symphony 來打造 Symphony。

當我們在內部示範這個系統如何管理任務並附上其工作證明影片時,反應非常正面:我們的 Symphony 項目頻道人數增加了,而且整個組織內各團隊都開始自發使用它。在 OpenAI,內部產品市場契合是對外推出產品的先決條件。根據我們在 OpenAI 看到的使用情況,我們清楚知道應該把 Symphony 分享給公司以外的人使用。

於是我們把這個想法抽離成一份獨立的 SPEC.md,並請 Codex 去實作它。對於參考實作,我們選擇了 Elixir,這是一種相對小眾但具備優秀原語、很適合協調及監督並行程序的語言。Codex 一次過就完成了 Elixir 實作,而之後我們持續迭代規格與實作。為完善規格,我們甚至請 Codex 以其他幾種語言實作,包括 TypeScript、Go、Rust、Java 及 Python,並利用結果找出含糊之處,簡化系統。Codex 在每種語言都成功完成實作。

在打造 Codex 的過程中,我們移除了很多附帶的複雜性,例如對特定程式碼庫或 Linear MCP 的依賴。Symphony 不再依賴我們的內部程式碼庫或工作流程。核心方法變得很簡單:

對於每個開放中的任務,都確保有一個智能代理在其專屬工作區中運行。

除了協助處理進行中的工作,開發流程現在亦成為智能代理理解並遵循的一部分。這套開發流程包括處理問題、取出程式碼庫、將狀態設為進行中以便項目經理知道工作正在處理、加入 PR、將狀態移至審核、附上影片等,現已記錄在一個簡單的 WORKFLOW.md 檔案中。這些原本都是人類團隊一直遵循的流程,但從未正式記錄下來。現在我們不再依賴這套隱含步驟,而是將其文件化,並由 Symphony 確保智能代理跟隨執行。這讓我們能建立真正與我們並肩工作的智能代理。如果我們決定智能代理亦應在完成工作後附上自我反思,我們只需將這一步加入 WORKFLOW.md,Symphony 便會引導智能代理執行。

我們亦使用了 Codex 的 應用程式伺服器模式(在新視窗中開啟),這是 Codex 內建的無頭模式。此模式讓我們可以透過文件完善的 JSON-RPC API,以程式方式運行 Codex 並與其互動,例如啟動對話串或回應各輪互動。相比透過 CLI 或即時 tmux 工作階段與 Codex 互動,這種方式更方便,也更易於擴展。

Codex 應用程式伺服器非常適合我們的使用情境:我們既能善用 Codex 提供的框架,同時保留可接入的調整選項和掛鈎。例如,為避免向子智能代理公開 Linear 存取權杖,我們使用動態工具調用(在新視窗中開啟),公開原始 linear_graphql 函數,讓它可對 Linear 執行任意請求,而毋須依賴 MCP 或向容器公開存取權杖。

展望將來

Symphony 是一個刻意保持精簡的協調層。我們將其開源,是為了展示 Codex 應用程式伺服器配合 Linear 等不同工作流程工具時的能力。因此,我們不打算將 Symphony 作為獨立產品維護。你可以把它視為參考實作。就像許多開發人員會讓他們的編碼智能代理參考框架工程文章,為自己的程式碼庫建立基本框架一樣,我們希望你也可以讓你常用的編碼智能代理參考 Symphony 的規格(在新視窗中開啟)程式碼庫(在新視窗中開啟),建立適合自己環境的版本。

真正的關鍵在於 Codex 及其應用程式伺服器。Symphony 的作用,是把我們本已在使用的 Codex 與 Linear 連接起來,從而解決工作管理問題。隨著編碼智能代理在推理及遵循指示方面不斷進步,我們預期其他公司的瓶頸亦會由撰寫程式碼,轉向管理智能代理工作。令人期待的是,現時試驗這類編碼智能代理系統的門檻已大幅降低,你只需使用 Codex 便可以開始建立。

社群致謝

我們很高興看到工程社群在發佈後數星期內採用 Symphony,截至 4 月 23 日,已獲得超過 1.5 萬個 GitHub 星星評分(在新視窗中開啟)