OpenSpec is a specification-driven development framework that records software requirements and implementation plans as readable Markdown artifacts. It helps developers and AI coding assistants agree on what should be built before code is written, including work spanning multiple repositories. The catalogue add-ons provide workflow skills and instructions for using OpenSpec.
Borrowing it
Nothing to install: this file belongs to Fission-AI/OpenSpec. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Fission-AI/OpenSpec/main/AGENTS.mdgit clone --depth 1 https://github.com/Fission-AI/OpenSpecWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/fission-ai/openspec/agents-md)<a href="https://agentmods.dev/instructions/fission-ai/openspec/agents-md"><img src="https://agentmods.dev/badge/instructions/fission-ai/openspec/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/fission-ai/openspec/agents-md"><img src="https://agentmods.dev/badge/instructions/fission-ai/openspec/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>The source is not reproduced here
Licensed MIT
The repository is licensed MIT, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 1 lines e3b0c44298fc
OpenSpec AGENTS.md is an instructions file published in the GitHub repository Fission-AI/OpenSpec (74,064 stars, last pushed yesterday), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. It was not scanned, because the body is not available under its licence. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
OpenSpec AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| OpenSpec AGENTS.mdFission-AI/OpenSpec | Instructions file | 74k | yesterday | MIT | — | — | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |