Add dataset items
⚠️
Preview — this feature is being built; the design below is the spec.
POST https://app.syntic.ai/v1/evals/datasets/{dataset_id}/itemsAdd up to 1,000 items in one call. For larger sets, upload a JSONL file and use import. The call is all-or-nothing: if one item fails validation, none are added.
For how this fits into a full workflow, see Evaluations.
Headers
| Header | Required | Value |
|---|---|---|
Authorization | Yes | Bearer <key>: a private inference key (sk_live_...). See Authentication. |
syntic-beta | Yes, while in preview | evals-2026-12-01. Without it the call fails with 400 beta_required. See Versioning. |
Content-Type | Yes | application/json |
Idempotency-Key | No | Up to 255 characters. Retrying with the same key within 24 hours returns the first result instead of acting twice. See Idempotency. |
Path parameters
| Parameter | Type | Description |
|---|---|---|
dataset_id | string | Starts with evds_. |
Body parameters
| Parameter | Type | Required | Notes |
|---|---|---|---|
items | array | Yes | Objects with input, optional ideal and tags. |
Response
201 Created, Content-Type: application/json
{
"dataset_id": "evds_01JD13B5D7F9H1K3M5P7",
"added": 2,
"item_ids": [
"evit_01JD24C6E8G0J2L4N6Q8",
"evit_01JD24D7F9H1K3M5P7R9"
],
"item_count": 202
}Examples
curl -sS "https://app.syntic.ai/v1/evals/datasets/evds_01JD13B5D7F9H1K3M5P7/items" \
-H "Authorization: Bearer $SYNTIC_API_KEY" \
-H "syntic-beta: evals-2026-12-01" \
-H "Idempotency-Key: 8d6f0c1e-4b2a-4a57-9f0e-2f1d3c4b5a69" \
-H "Content-Type: application/json" \
-d '{
"items": [
{
"input": {
"ticket": "I was charged twice for order 88123.",
"customer_tier": "gold"
},
"ideal": "Apologise, confirm the duplicate charge, say the refund is issued within 3 working days.",
"tags": [
"billing"
]
},
{
"input": {
"ticket": "How do I export my invoices?"
},
"ideal": "Point to Settings, Billing, Export, and mention CSV and PDF.",
"tags": [
"how-to"
]
}
]
}'Errors
Errors use the error envelope and carry a request_id. Codes specific to this operation:
| Status | type | code | When |
|---|---|---|---|
| 400 | invalid_request_error | beta_required | The syntic-beta header is missing. |
| 400 | invalid_request_error | item_invalid | An item fails input_schema; param points at it. |
| 409 | conflict_error | dataset_full | The dataset would exceed 50,000 items. |
| 404 | not_found_error | dataset_not_found | No dataset with this id. |
| 401 | authentication_error | invalid_api_key | The key is missing, unknown, revoked or expired. |
| 429 | rate_limit_error | rate_limited | Too many requests; wait for Retry-After. See Rate-limit headers. |
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