# CONTEXT_USE_INVALID

- Surface: API
- HTTP status: 400
- Details: `{ issues: Array<{ path: string[], message: string }> }`

## Remediation

Supply a live MCP session plus non-empty appId and environmentId

## Cause

context_use was called without a session, or with empty or unusable App and Environment arguments.

## Fix

Open or keep an MCP session, then resend `appId` and `environmentId` as non-empty strings. `details.issues` names the fields to correct.

## Related

- [SCOPE_UNRESOLVED](https://splitch.dev/docs/error/SCOPE_UNRESOLVED)
- [VALIDATION_ERROR](https://splitch.dev/docs/error/VALIDATION_ERROR)

Source: https://splitch.dev/docs/error/CONTEXT_USE_INVALID