Errors and limits - Connie

Error format

Errors return JSON with a readable message and, usually, a machine-readable code:

{ "error": "Human-readable message", "code": "MACHINE_CODE" }

Validation errors may also include details about which field was wrong.

Status codes

Status	Code	When
400	`VALIDATION_ERROR`	The body isn’t valid JSON, a field is missing or has the wrong type, or a required parameter is missing.
401	`UNAUTHORIZED`	No session was sent (“Unauthorized - please sign in”).
401	`SESSION_EXPIRED`	The session expired. Copy a fresh Cookie header. See Authentication.
402	`PAYMENT_REQUIRED` / `INSUFFICIENT_CREDITS`	The workspace doesn’t have enough credits for this action. See Credits.
403	`FORBIDDEN`	You aren’t a member of the workspace, your role can’t do this, or the request came from another website (“Cross-origin request blocked”).
403	`WAITLISTED`	Your account is still on the waitlist.
403	—	`{"error":"Browser origin denied."}`: a browser on another site called the API.
404	`NOT_FOUND`	The item doesn’t exist, or isn’t in that workspace.
409	`CONFLICT` (or a specific code)	The change clashes with the current state, for example a name that’s already taken.
429	`RATE_LIMIT_EXCEEDED`	Too many requests. Wait for the time in `Retry-After`.
429	`BUDGET_EXCEEDED`	The AI usage budget for this period is used up.
500	`INTERNAL_ERROR`	Something went wrong on Connie’s side. Try again; if it keeps happening, contact support.
503	`DATABASE_UNAVAILABLE` / `AI_PROVIDER_UNAVAILABLE`	A service is temporarily unavailable. Retry after `Retry-After` if present.

Rate limits

Some endpoints, mainly AI, Inbox and import endpoints, are rate limited per user. Limits are higher on paid plans: Starter gets 3 times the Free limit and Scale 10 times. When you hit a limit you get 429 with these headers:

Header	Meaning
`Retry-After`	Seconds to wait before retrying
`X-RateLimit-Limit`	Requests allowed in the window
`X-RateLimit-Remaining`	Requests left in the window
`X-RateLimit-Reset`	When the window resets

Back off and retry after Retry-After. The MCP server has its own limits; see MCP errors and limits.

Credits

Endpoints that run paid actions (AI replies, paid tools, imports past the free allowance) charge the workspace’s credits exactly as the app does. If there aren’t enough, you get 402. See Credits.