OptionalmaxMaximum response body size (in octets) the SDK will read before aborting
with ResponseTooLargeError. When unset, the SDK does not impose a cap —
matches the underlying MCP / A2A transport defaults.
Set this when crawling untrusted agents (registries, federated
discovery layers, monitoring tools) to prevent a hostile vendor from
buffering a large reply before any application-layer schema validation
runs. Counted across response chunks; pre-cancels when Content-Length
exceeds the cap. Applies to A2A agent-card discovery
(/.well-known/agent.json) on the same call as well.
Per-call override (TaskOptions.transport.maxResponseBytes) beats the
value set on the client constructor (SingleAgentClientConfig.transport).
Safe to set on all calls. SSE responses (text/event-stream) are
passed through unchanged — a single tool call legitimately emits N status
frames + a final result, bounded by protocol-level framing rather than
cumulative byte counts. The cap applies to one-shot JSON responses
(get_adcp_capabilities, agent-card lookup, tool result payloads on
non-streaming transports) where the body is bounded by definition.
Transport-level safeguards applied to a call.
Wired into the SDK's internal fetch chain via AsyncLocalStorage, so the cap takes effect even when the underlying transport's connection cache reuses a fetch that was created on an earlier call with different limits.