Wrapping 883 App Store Connect Endpoints in MCP: Engineering Agent Usability
erayendes · reddit · 2026-08-13
A developer wrapped all 883 Apple App Store Connect API endpoints into an MCP server and shared key engineering lessons for improving agent usability.
Core Challenges & Solutions
- Token Bloat: The full API surface exceeds 100k tokens, making it impossible to load. The solution splits it into 13 profiles, narrowed further with colons (e.g., monetization:subscription-pricing yields only 26 tools).
- Tool Count ≠ Usability: Real bugs often stem from tool designs that fail to match natural language goals. For instance, asking for global subscription prices initially forced the agent to fallback to raw endpoints and hand-coded Python, costing 1.02M tokens ($3.01). Fixing the macro to return grouped global data collapsed the response to 1.3k tokens.
- Risk Annotation: The eval harness surfaced 100 non-DELETE write operations affecting money, releases, or access, which are now explicitly marked with risk levels.
The project is open-source on GitHub (MIT), runs locally via stdio, stores keys in macOS Keychain, and includes zero telemetry.
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