OpenSpec
OpenSpec is a lightweight command-line tool for software developers that automatically generates structured specification documents before coding begins, reducing discrepancies between development intent and actual implementation. Its core workflow spans four phases: propose, continue, apply, and archive. Specification documents are stored in plain Markdown format, require no specific framework or environment dependencies, and are designed to work alongside AI-assisted programming tools.
Core Facts
The development of AI coding tools has gone through three stages: code completion, conversational code generation, and autonomous development agents.
AI model lifecycle management is increasingly important for developers, requiring the establishment of clear deployment, monitoring, and retirement mechanisms.
OpenSpec's Explore mode lets the AI freely explore the codebase, helping to analyze architecture, identify bottlenecks, and understand existing designs.
Timeline (last 90 days)
The author analyzed 788 open-source repositories using the OpenSpec pattern and found that the write-back step is manual and that no one maintains the text no one reads.
OpenSpec's verification step (/opsx:verify) is part of the extended workflow configuration, enabled via openspec config profile.
Everything in OpenSpec is placed under the openspec/ folder, divided into two parts: specs/ (the source of truth for current system behavior) and changes/ (proposed modifications, one folder per change).
OpenSpec's workflow consists of six steps: explore (/opsx:explore), propose (/opsx:propose <name>), review, apply (/opsx:apply), verify (/opsx:verify), archive (/opsx:archive).
OpenSpec is not a new IDE or platform that you need to migrate to, but rather a Markdown folder in the repository, a small CLI, and a set of instructions for agents.
OpenSpec's core concept is the delta spec: a change does not restate the entire spec, but only describes the added, modified, or deleted parts.
After OpenSpec archiving, the delta is merged into specs/, the change folder is moved into changes/archive/ with a date prefix, the spec describes the system's current state, and the archived change retains the full context.
In OpenSpec's delta specs, scenarios are treated as the acceptance criteria for requirements: each Requirement under ADDED Requirements is followed by several Scenarios, covering the normal path, boundaries, and exceptions respectively.
GitHub's SpecKit provides slash commands such as constitution, plan, tasks, and implement, while FissionAI's OpenSpec follows a propose → explore → apply → archive workflow.
OpenSpec does not generate code directly, but instead optimizes the input fed to the AI.
12 more timeline events
All Facts (20)
The development of AI coding tools has gone through three stages: code completion, conversational code generation, and autonomous development agents.
90%VerifiedAI model lifecycle management is increasingly important for developers, requiring the establishment of clear deployment, monitoring, and retirement mechanisms.
65%VerifiedOpenSpec's Explore mode lets the AI freely explore the codebase, helping to analyze architecture, identify bottlenecks, and understand existing designs.
65%UnverifiedOpenSpec的Apply命令会将源Spec和DeltaSpec自动合并成最新版本
90%UnverifiedDeltaSpec通过edit新增、modify修改、remove删除三种操作来描述变化
90%UnverifiedOpenSpec使用Devon文档格式来描述需求场景
90%UnverifiedOpenSpec使用DAG（有向无环图）产物依赖图机制，依次产出Proposal、Specs、Design、Tasks四份需求文件
90%Unverified一个功能从想法到上线需要经过七步流程：需求产物生成、Auto Plan评审、TDD编码、Review审查、QA验收、SHIP发布、Archive归档
85%UnverifiedGStack的SHIP命令会自动触发OpenSpec的Archive操作，将本次迭代的Delta规范合入主规范，完成从需求到发布再到归档的闭环
85%UnverifiedGStack的Auto Plan模块从四个维度评审OpenSpec产物：CEO视角看商业价值、工程视角看技术可行性、设计视角看用户体验、DX视角看开发者友好度
85%UnverifiedDeltaSpec增量变更机制将规范输出从800行压缩到250行，比传统方式短70%
70%UnverifiedOpenSpec's Propose command generates 4 files at once: Proposal.md, Specs, Design.md, and Task.md.
60%UnverifiedOpenSpec's core workflow contains four commands: Propose, Continue, Apply, and Archive.
60%UnverifiedOpenSpec does not require an API Key and is stored purely in Markdown within the code repository.
60%UnverifiedThe author analyzed 788 open-source repositories using the OpenSpec pattern and found that the write-back step is manual and that no one maintains the text no one reads.
50%UnverifiedOpenSpec's workflow consists of six steps: explore (/opsx:explore), propose (/opsx:propose <name>), review, apply (/opsx:apply), verify (/opsx:verify), archive (/opsx:archive).
50%UnverifiedOpenSpec's verification step (/opsx:verify) is part of the extended workflow configuration, enabled via openspec config profile.
50%UnverifiedAfter OpenSpec archiving, the delta is merged into specs/, the change folder is moved into changes/archive/ with a date prefix, the spec describes the system's current state, and the archived change retains the full context.
50%UnverifiedIn OpenSpec's delta specs, scenarios are treated as the acceptance criteria for requirements: each Requirement under ADDED Requirements is followed by several Scenarios, covering the normal path, boundaries, and exceptions respectively.
50%UnverifiedOpenSpec is not a new IDE or platform that you need to migrate to, but rather a Markdown folder in the repository, a small CLI, and a set of instructions for agents.
50%