Body buffering

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Buffer request and response bodies before forwarding them.

Attaches to: Route

Use the policies.buffer policy to buffer request or response bodies in the proxy before the bodies are forwarded. By default, agentgateway streams bodies. When you configure policies.buffer, the proxy accumulates the configured body direction in memory until the body is complete, and then forwards it.

Note

This policy is different from gateway-level buffering, which configures the frontendPolicies.http.maxBufferSize limit used by policies that need buffering.

Buffer settings

You can configure request buffering, response buffering, or both.

Field	Description	Default
policies.buffer.request.maxBytes	Maximum number of request body bytes to buffer.	Uses the global proxy buffer setting, which defaults to 2 MiB.
policies.buffer.request.failureMode	Behavior when the request body exceeds maxBytes: failClosed to reject the request, or failOpen to continue.	failClosed
policies.buffer.response.maxBytes	Maximum number of response body bytes to buffer.	Uses the global proxy buffer setting, which defaults to 2 MiB.
policies.buffer.response.failureMode	Behavior when the response body exceeds maxBytes: failClosed to reject the response, or failOpen to continue.	failClosed

The maxBytes value is a number of bytes, such as 65536 for 64 KiB. Large buffered bodies can increase proxy memory usage, so set strict limits for routes that receive untrusted or large payloads. When a body exceeds the applicable buffer limit, agentgateway rejects the body if possible. If response headers were already sent before the limit is exceeded, the proxy closes the connection.

Buffer request and response bodies

Use the route’s policies block to configure body buffering.

# yaml-language-server: $schema=https://agentgateway.dev/schema/config
gateways:
  default:
    port: 3000
routes:
- backends:
  - host: localhost:8080
  policies:
    buffer:
      request:
        maxBytes: 65536
      response:
        maxBytes: 262144