mcpbeat

Openspec Propose

posthog/openspec-propose

Propose a new change with all artifacts generated in one step. Use when the user wants to quickly describe what they want to build and get a complete proposal with design, specs, and tasks ready for implementation.

1k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
1
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/PostHog/sdk-specs --skill openspec-propose

What it tells the agent to use

found in the instruction text
Write writes files

The instruction itself

as written by the author

Propose a new change - create the change and generate all artifacts in one step.

I'll create a change with artifacts:

  • proposal.md (what & why)
  • design.md (how)
  • tasks.md (implementation steps)

When ready to implement, run /opsx:apply


Input: The user's request should include a change name (kebab-case) OR a description of what they want to build.

Steps

  • If no clear input provided, ask what they want to build

Use the AskUserQuestion tool (open-ended, no preset options) to ask:

> "What change do you want to work on? Describe what you want to build or fix."

From their description, derive a kebab-case name (e.g., "add user authentication" → add-user-auth).

IMPORTANT: Do NOT proceed without understanding what the user wants to build.

  • Create the change directory
   openspec new change "<name>"

This creates a scaffolded change at openspec/changes/<name>/ with .openspec.yaml.

  • Get the artifact build order
   openspec status --change "<name>" --json

Parse the JSON to get:

  • applyRequires: array of artifact IDs needed before implementation (e.g., ["tasks"])
  • artifacts: list of all artifacts with their status and dependencies
  • Create artifacts in sequence until apply-ready

Use the TodoWrite tool to track progress through the artifacts.

Loop through artifacts in dependency order (artifacts with no pending dependencies first):

a. For each artifact that is ready (dependencies satisfied):

  • Get instructions:
        openspec instructions <artifact-id> --change "<name>" --json
  • The instructions JSON includes:
  • context: Project background (constraints for you - do NOT include in output)
  • rules: Artifact-specific rules (constraints for you - do NOT include in output)
  • template: The structure to use for your output file
  • instruction: Schema-specific guidance for this artifact type
  • outputPath: Where to write the artifact
  • dependencies: Completed artifacts to read for context
  • Read any completed dependency files for context
  • Create the artifact file using template as the structure
  • Apply context and rules as constraints - but do NOT copy them into the file
  • Show brief progress: "Created <artifact-id>"

b. Continue until all applyRequires artifacts are complete

  • After creating each artifact, re-run openspec status --change "<name>" --json
  • Check if every artifact ID in applyRequires has status: "done" in the artifacts array
  • Stop when all applyRequires artifacts are done

c. If an artifact requires user input (unclear context):

  • Use AskUserQuestion tool to clarify
  • Then continue with creation
  • Show final status
   openspec status --change "<name>"

Output

After completing all artifacts, summarize:

  • Change name and location
  • List of artifacts created with brief descriptions
  • What's ready: "All artifacts created! Ready for implementation."
  • Prompt: "Run /opsx:apply or ask me to implement to start working on the tasks."

Artifact Creation Guidelines

  • Follow the instruction field from openspec instructions for each artifact type
  • The schema defines what each artifact should contain - follow it
  • Read dependency artifacts for context before creating new ones
  • Use template as the structure for your output file - fill in its sections
  • IMPORTANT: context and rules are constraints for YOU, not content for the file
  • Do NOT copy <context>, <rules>, <project_context> blocks into the artifact
  • These guide what you write, but should never appear in the output

Guardrails

  • Create ALL artifacts needed for implementation (as defined by schema's apply.requires)
  • Always read dependency artifacts before creating a new one
  • If context is critically unclear, ask the user - but prefer making reasonable decisions to keep momentum
  • If a change with that name already exists, ask if user wants to continue it or create a new one
  • Verify each artifact file exists after writing before proceeding to next

How to use it

Copy the folder

Take posthog/openspec-propose from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.