Setting the file. One moment.
Repo Contract And Validation · ChatGPT Apps · openai/skills · Skills Docs
Load this reference when scaffolding or reviewing a generated ChatGPT app repo.
The goal is not “files were created.” The goal is “the repo is plausibly runnable and follows a stable working-app contract.”
Every generated repo should satisfy the relevant parts of this contract.
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The repo shape matches the chosen archetype.
The repo structure is simple enough that a user can identify where the server and widget live.
There is a clear MCP server entry point.
The server exposes /mcp.
The server registers tools intentionally.
If a UI exists, the server registers a resource/template with the MCP Apps UI MIME type.
Each tool maps to one user intent.
Descriptions help the model choose the tool.
Required annotations are present and accurate.
UI-linked tools use _meta.ui.resourceUri.
_meta["openai/outputTemplate"] is treated as optional compatibility, not the primary contract.When the app is connector-like, data-only, sync-oriented, or intended for company knowledge or deep research, it implements standard search and fetch tools instead of custom substitutes.
The widget initializes the MCP Apps bridge when needed.
The widget can receive ui/notifications/tool-result.
The widget renders from structuredContent.
Interactive widgets use tools/call.
Baseline follow-up messaging uses ui/message.
window.openai is optional and additive.
There is a clear way to start the app locally.
There is at least one low-cost check command when the stack supports it.
The response explains how to connect the app in ChatGPT Developer Mode when relevant.
Run the highest level you can without overfitting to a single stack.
chosen archetype is sensible
repo shape matches archetype
/mcp route is presenttool/resource/widget responsibilities are coherent
if the app is connector-like or sync-oriented, search and fetch are present with the expected standard shape
Use the stack-appropriate cheapest check available, for example:
Python syntax check
TypeScript compile check
framework-specific lint or build sanity check if already installed
start the server
confirm the health route or /mcp endpoint responds
inspect with MCP Inspector
test through ChatGPT Developer Mode
confirm widget updates after tool results
Always say which validation level was reached and what was not run.
That makes the skill more reliable because it separates:
“repo shape looks right”
“syntax is valid”
“server starts”
“host integration was actually exercised”
references/repo-contract-and-validation.md