Limits
Keep call tasks bounded and leave room for API rate limits.
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Task limits
- Input
- Destination
- Accepted range
- E.164 format, 8–15 digits after the + prefix, without spaces or punctuation.
- Input
- Objective
- Accepted range
- 1–4,000 characters.
- Input
- Protected context
- Accepted range
- Up to 20 named strings, 1–2,000 characters each; combined UTF-8 value bytes at most 16 KiB. Names match [a-z][a-z0-9_]{0,63}.
- Input
- Constraints / success criteria
- Accepted range
- Up to 50 strings each, at most 500 characters per string.
- Input
- Requested duration
- Accepted range
- 30–3,600 seconds; default 300. Workspace, assistant, or calling-service limits may be lower.
- Input
- Idempotency key
- Accepted range
- Non-empty, up to 200 characters.
| Input | Accepted range |
|---|---|
| Destination | E.164 format, 8–15 digits after the + prefix, without spaces or punctuation. |
| Objective | 1–4,000 characters. |
| Protected context | Up to 20 named strings, 1–2,000 characters each; combined UTF-8 value bytes at most 16 KiB. Names match [a-z][a-z0-9_]{0,63}. |
| Constraints / success criteria | Up to 50 strings each, at most 500 characters per string. |
| Requested duration | 30–3,600 seconds; default 300. Workspace, assistant, or calling-service limits may be lower. |
| Idempotency key | Non-empty, up to 200 characters. |
The calling service also caps serialized call context at 16 KiB, including task instructions, context, schema, and caller identity. Keep these inputs concise; satisfying each field’s individual limit does not guarantee the combined task fits.
A requested call-duration limit is separate from an HTTP client timeout. Timing out a request or closing a polling process does not cancel an active call.
Request rate limits
The gateway defaults to 120 requests per minute per API key and 600 authentication attempts per minute per client IP. Deployment settings can change these limits. Call-frequency and destination limits can apply separately.
On 429 rate_limit_exceeded, honor the Retry-After header. Poll one active call every few seconds and stop at a terminal state. Account for all active calls when choosing a polling interval.
Account availability
Public API calls use the owning workspace’s assistant, permissions, and usage availability. Check the platform for current account and billing details. Passing input validation does not guarantee that a call is eligible to start.