## TL;DR
One of the **product-store-state** MCP tools served from `https://mcp.revenuecat.ai/mcp` has a JSON Schema
containing an integer literal that exceeds the signed 64-bit range (most likely a `maximum` / `default` /
`multipleOf` on a price/amount/timestamp field). When an MCP client forwards that tool definition to the
Anthropic Messages API, the API rejects the **entire** `tools` array with:
API Error: 400 tools.61.custom.input_schema: int too big to convert
Because the failure happens at tool-definition validation time, *every* request that includes that tool
fails — so the tools can't be loaded at all, which blocks any workflow that uses them (e.g. creating /
submitting products to App Store Connect through the MCP).
This is a different bug from the earlier `create-webhook-integration` null-in-string-enum issue
(community tid=7623, fixed 2026-04-28) — same class of problem (an illegal schema value served by the MCP),
different tool and field.
## Affected tools
The error appears while loading the **product store state** tool group, i.e. one (or more) of:
`create-product-store-state-plan`, `plan-product-store-state-plan`, `apply-product-store-state-plan`,
`update-product-store-state-plan`, `discard-product-store-state-plan`, `list-product-store-state-plans`,
`get-product-store-state-plan`, `get-product-store-state`, `set-product-store-state`,
`get-product-store-state-operation`, `submit-products-to-store`, `create-product-in-store`,
`upload-product-store-state-screenshot`.
(I could not pinpoint the exact tool by loading them individually, because activating the offending schema
poisons every subsequent request to the same Anthropic endpoint.)
## Reproduction
1. Connect the RevenueCat MCP (`https://mcp.revenuecat.ai/mcp`) to an MCP client backed by the Anthropic
Messages API (e.g. Claude Code / Claude Desktop).
2. Trigger loading of the product-store-state tool schemas (e.g. ask the agent to create / submit products
to App Store Connect).
3. The next model request fails with `400 tools.<n>.custom.input_schema: int too big to convert`.
## Likely root cause
A numeric keyword in one product-store-state tool's input schema is outside the range Anthropic's schema
validator accepts (it parses schema integers as signed 64-bit). Typical culprits:
- `maximum` set to an unsigned 64-bit max (`18446744073709551615` = 2^64−1) or larger,
- a `default` / `const` / `multipleOf` holding micros/nanos or an epoch-ms constant beyond 2^63−1.
## Suggested fix
Audit numeric bounds (`maximum`, `minimum`, `default`, `const`, `multipleOf`, enum members) across the
product-store-state tool schemas and clamp them to a safe range — ideally ≤ `2^53 − 1` (JSON safe-integer),
at most signed-64-bit. For "no practical upper bound", drop `maximum` rather than emitting a huge sentinel.
## Environment
- MCP endpoint: `https://mcp.revenuecat.ai/mcp`
- Client: Claude Code (Anthropic Messages API)
- Date observed: 2026-06-20
- Other RevenueCat MCP tools (`list-projects`, `list-products`, `list-offerings`, `list-entitlements`,
`list-apps`) load and respond normally — the failure is isolated to the product-store-state tool group.
