> ## Documentation Index
> Fetch the complete documentation index at: https://docs.atomscale.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Ingest Chunk

> Ingest a single chunk of time series data for one channel

Uploads a chunk of time series data for a single channel. Uses `chunk_index` to compute deterministic array positions, making the operation idempotent: retrying the same `(data_id, channel_name, chunk_index)` combination replaces the same slice rather than appending.

<ParamField body="data_id" type="string" required>
  Data ID returned from stream initialization
</ParamField>

<ParamField body="chunk_index" type="integer" required>
  Zero-based chunk index for ordering. Must be >= 0.
</ParamField>

<ParamField body="channel_name" type="string" required>
  Name of the data channel (e.g., `thickness`, `temperature`). Must be 1-255 characters.
</ParamField>

<ParamField body="timestamps" type="array" required>
  Array of Unix epoch timestamps in seconds
</ParamField>

<ParamField body="values" type="array" required>
  Array of measured values corresponding to each timestamp
</ParamField>

<ParamField body="units" type="string">
  Units for the values (e.g., `nm`, `C`)
</ParamField>

## Response

<ResponseField name="data_id" type="string">
  The data ID for this stream
</ResponseField>

<ResponseField name="channel_name" type="string">
  The channel name that was updated
</ResponseField>

<ResponseField name="chunk_index" type="integer">
  The chunk index that was ingested
</ResponseField>

<ResponseField name="total_points" type="integer">
  Total number of data points now stored for this channel
</ResponseField>

<RequestExample>
  ```python SDK theme={null}
  from atomscale.streaming import TimeseriesStreamer

  streamer = TimeseriesStreamer(api_key="YOUR_API_KEY", points_per_chunk=100)
  streamer.push(
      data_id="d290f1ee-6c54-4b01-90e6-d701748f0851",
      chunk_index=0,
      channel_name="thickness",
      timestamps=[1705312200.0, 1705312210.0, 1705312220.0],
      values=[0, 5.2, 10.1],
      units="nm",
  )
  ```

  ```python Python theme={null}
  import requests

  response = requests.post(
      "https://api.atomscale.ai/metrology/stream/chunk",
      headers={
          "X-API-KEY": "YOUR_API_KEY",
          "Content-Type": "application/json"
      },
      json={
          "data_id": "d290f1ee-6c54-4b01-90e6-d701748f0851",
          "chunk_index": 0,
          "channel_name": "thickness",
          "timestamps": [1705312200.0, 1705312210.0, 1705312220.0],
          "values": [0, 5.2, 10.1],
          "units": "nm"
      }
  )
  result = response.json()
  ```

  ```bash cURL theme={null}
  curl -X POST "https://api.atomscale.ai/metrology/stream/chunk" \
    -H "X-API-KEY: YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "data_id": "d290f1ee-6c54-4b01-90e6-d701748f0851",
      "chunk_index": 0,
      "channel_name": "thickness",
      "timestamps": [1705312200.0, 1705312210.0, 1705312220.0],
      "values": [0, 5.2, 10.1],
      "units": "nm"
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json 201 theme={null}
  {
    "data_id": "d290f1ee-6c54-4b01-90e6-d701748f0851",
    "channel_name": "thickness",
    "chunk_index": 0,
    "total_points": 3
  }
  ```
</ResponseExample>