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Bug Report: MCP create_or_update_person and create_or_update_prospect returning 400
Environment: DecileHub MCP via Claude (Cowork mode) Date: April 13, 2026
Summary Both create_or_update_person and create_or_update_prospect fail with a 400 error on all create operations, making it impossible to add new contacts or prospects through the MCP integration.
Steps to Reproduce
- Call create_or_update_person with required fields: first_name, last_name, email
- Observe the 400 response
Expected: New person record created successfully Actual:
HTTP 400 — {"error": "param is missing or the value is empty or invalid: people"}
Additional findings
- Same error occurs on create_or_update_prospect with valid pipeline_id, stage_id, and people array
- Tried both {"people": {...}} and {"person": {...}} wrapper formats via debug_api_request — both returned the account object instead of creating a record, suggesting the request body may not be reaching the endpoint correctly
- Read operations (list_pipelines, get_pipeline, list_people) work fine — issue is isolated to write/create operations
Workaround: None via MCP — must create contacts manually in the DecileHub UI
Has anyone else run into this? Happy to share additional logs if helpful.
