---
title: "Augment seed data to generate synthetic data"
method: POST
path: "/augment"
---

# Augment seed data to generate synthetic data

`POST /augment`

## Request body

- object
  - `multiple` integer — Number of synthetic examples to generate per seed example (max 50)
  - `eval_results_id` string — ID of evaluation results to use for target metrics (will use latest if not provided)
  - `include_gathered` boolean — If true, includes gathered pairs (high-scoring and positively critiqued) in the synthetic dataset
  - `pair_query` object — Optional query parameters to filter seed dataset pairs
    - `latest_n_pairs` integer — Maximum number of latest pairs to include (defaults to MaxCorpusSize if not provided)
    - `pair_label` string — Filter pairs by label (optional)
  - `target_metric_idx` integer[], required — Array of indices of target metrics for redrafting synthetic data (from the evaluation results)

## Response `200`

Data successfully augmented

- object
  - `synthetic_data_id` string — ID of the generated synthetic dataset
  - `created_at` string — Timestamp when the synthetic data was created
  - `seed_data_size` integer — Number of pairs in the original seed dataset
  - `synthetic_data_size` integer — Total number of pairs in the synthetic dataset (including gathered pairs if include_gathered is true)
  - `system_prompt` string — System prompt used for the synthetic data
  - `target_metrics` string[] — Array of target metrics that were used for redrafting

## Other responses

- `400` — Bad request - malformed JSON or missing required fields
- `403` — Forbidden - token count exceeds plan limit
- `500` — Internal server error - various failures during augmentation process

## Changes

- **2025-07-03** `7a3463d3306a` — 1 breaking, 3 warning, 5 info
  - added the new required request property `target_metric_idx`
  - removed the request property `seed_data_id`
  - removed the request property `target_metric`
  - removed the optional property `target_metric` from the response with the `200` status
  - …5 more
- **2025-06-10** `d550ab79ee7e` — 3 info
  - added the new optional request property `pair_query`
  - added the new optional request property `target_metric`
  - the request property `seed_data_id` became optional
- **2025-04-30** `2eb8cb01b88b` — 1 info
  - endpoint added
- **2025-04-30** `9a3d86c43d3d` — 1 breaking
  - api path removed without deprecation

[Change history](https://skmtc.dev/getplumai/apis/plum-api/changes/augment/post.md)

---

[API](https://skmtc.dev/getplumai/apis/plum-api.md) · [All operations](https://skmtc.dev/getplumai/apis/plum-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/getplumai/plum-api/revisions/a9fca2bc07fe/schema)