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

# Encoding

> Configure how Tangent formats and compresses sink output before upload.

The `encoding` block defines **how Tangent serializes and compresses records** before writing them to a sink (e.g., S3, File).\
It controls file format, schema handling (for Avro/Parquet), and data compression.

***

## Schema

<ParamField path="encoding.type" type="string" required>
  Output format for serialized records.\
  Defaults to `ndjson`.

  **Options**

  * `ndjson` — newline-delimited JSON; one record per line
  * `json` — standard JSON array of records
  * `avro` — Apache Avro binary encoding (requires schema)
  * `parquet` — Apache Parquet columnar format (requires schema)
</ParamField>

<ParamField path="encoding.schema" type="string">
  Path to a schema file required by `avro` and `parquet` formats.\
  Can point to a local `.avsc` (Avro) or `.json` (Arrow/Parquet) schema.
</ParamField>

<ParamField path="compression" type="string | object">
  Configures compression for the encoded data.\
  Defaults to `zstd` with level `3`.

  **Options**

  * `none` — no compression
  * `gzip` — standard Gzip (`.gz` extension, level 6 default)
  * `zstd` — Zstandard (`.zst` extension, level 3 default)
  * `snappy` — Snappy block compression (Avro-only)
  * `deflate` — Deflate stream compression (Avro-only)

  **Examples**

  ```yaml theme={null}
  compression:
    type: gzip
    level: 6
  ```

  ```yaml theme={null}
  compression:
    type: zstd
    level: 3
  ```

  **Notes**

  * For **Avro** and **Parquet**, compression applies to **data blocks inside the file**, not the file as a whole.
  * Tangent automatically appends compression extensions when applicable (e.g. `.gz`, `.zst`).
</ParamField>

***

## Examples

### NDJSON (default)

```yaml tangent.yaml icon=upload theme={null}
encoding:
  type: ndjson
  compression:
    type: zstd
    level: 3
```

### Parquet with Arrow schema

```yaml tangent.yaml icon=upload theme={null}
encoding:
  type: parquet
  schema: ./schemas/arrow_schema.json
  compression:
    type: gzip
```

### Avro with explicit schema

```yaml tangent.yaml icon=upload theme={null}
encoding:
  type: avro
  schema: ./schemas/events.avsc
  compression:
    type: deflate
```

***

## Defaults Summary

| Setting             | Default                 | Description               |
| ------------------- | ----------------------- | ------------------------- |
| `encoding.type`     | `ndjson`                | Newline-delimited JSON    |
| `encoding.schema`   | —                       | Required for Avro/Parquet |
| `compression.type`  | `zstd`                  | Data compression method   |
| `compression.level` | `3` (zstd) / `6` (gzip) | Compression strength      |

***

## See also

* [S3 Sink](/configuration/sinks/s3)
* [File Sink](/configuration/sinks/file)
* [Compression](/configuration/sinks/compression)