Bid Traffic Compression

HTTP compression support for OpenRTB bid requests and responses

CloudX supports gzip and zstd compression for OpenRTB traffic exchanged with demand partners.

• Bid responses: inspect each request’s Accept-Encoding header and compress the response only with an encoding it lists.
• Bid requests: CloudX compresses request bodies per bidder endpoint, enabled in coordination with CloudX.

Bid requests

When compression is enabled, CloudX compresses the OpenRTB JSON request body and identifies the algorithm with the HTTP Content-Encoding header:

Content-Encoding: zstd
Content-Type: application/json

Bidder endpoints must decompress the body before parsing the OpenRTB request.

Each bid request advertises the response encodings CloudX accepts for that request. The default endpoint configuration sends:

Accept-Encoding: gzip, zstd

Bid responses

Inspect Accept-Encoding on every request and compress the response only with a listed encoding. Endpoint configuration can change the advertisement; a request that omits the header requires an uncompressed response. Set Content-Encoding to the algorithm used:

Content-Encoding: zstd
Content-Type: application/json

Do not send a compressed body without the matching Content-Encoding header.

Bid responses are limited to 17 MiB in compressed form and 16 MiB after decompression. Oversized responses are rejected and are not retried uncompressed.

Failure handling and rollback

A response with an unsupported encoding, a compressed body with a missing or mismatched Content-Encoding header, or a body that cannot be decompressed is invalid and excluded from the auction. CloudX does not automatically retry the response without compression.

If compressed responses fail, your endpoint can recover on its own by sending the OpenRTB JSON uncompressed, or by using another encoding advertised on that request. To revert compressed bid requests to gzip or uncompressed traffic, contact CloudX.

Enablement

Response compression is self-serve when the request advertises an encoding: compress the response with that encoding and set Content-Encoding accordingly. To receive compressed bid requests, contact CloudX to coordinate enablement and validation for your bidder endpoint. gzip remains supported for existing integrations.