Swift SDK: deliveries (ack/fail/defer) (TS participant SDK parity)

[willwashburn]

What the TS participant SDK provides

AgentRelay.deliveries (packages/sdk/src/agent-relay.ts) exposes RelayMessaging['deliveries'] (packages/sdk/src/messaging/types.ts, readonly deliveries):

• ack(messageId): Promise<RelayDeliveryResult>
• fail(messageId, reason?): Promise<RelayDeliveryResult>
• defer(messageId, deferUntil?): Promise<RelayDeliveryResult>

These let a participant acknowledge, reject, or defer a delivered message so the relay can track delivery state and stop redelivering.

What the Swift AgentRelaySDK lacks

AgentClient receives messages via the events / inboundMessages streams but has no way to ack/fail/defer a delivery by messageId. Without this, delivered messages cannot be marked handled from the Swift side.

Proposed Swift API sketch

public struct RelayDeliveryResult: Decodable, Sendable {}

extension AgentClient {
    public func ackDelivery(_ messageId: String) async throws -> RelayDeliveryResult
    public func failDelivery(_ messageId: String, reason: String? = nil) async throws -> RelayDeliveryResult
    public func deferDelivery(_ messageId: String, until: Date? = nil) async throws -> RelayDeliveryResult
}

Part of bringing the Swift AgentRelaySDK to parity with the TS participant SDK (follow-up to #1143 / #1147).

[willwashburn]

Closing as resolved-by-strategy: AgentRelaySDK (the relay-owned Swift facade this issue targeted) is being retired — it was always a thin wrapper over relaycast's official Swift SDK, and that SDK already implements delivery lifecycle handling natively.

Relaycast's Relaycast product provides AgentClient.deliveries(options:), .ackDelivery(_:), .failDelivery(_:options:), and .deferDelivery(_:options:).

Swift consumers needing hosted-workspace participation should depend on relaycast's Relaycast product directly (https://github.com/AgentWorkforce/relaycast.git) going forward instead of AgentRelaySDK, which no longer ships from this repo.

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[willwashburn]

Reopening: course reversal on PR #1259. Rather than retiring AgentRelaySDK and pointing consumers at relaycast's SDK directly, we're rebuilding it as a real sidecar matching @agent-relay/sdk's TS facade (relay-specific abstractions on top of relaycast, not just a rename-and-delegate wrapper) — same model the TS SDK already uses. This issue's ask will be implemented directly rather than closed by strategy.

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Generated by Claude Code

[willwashburn]

Closing as resolved — shipped in the Swift SDK facade rebuild (#1259). RelayDeliveries provides ack/fail(reason:)/defer(until:) over the engine's ackDelivery/failDelivery/deferDelivery, exposed as AgentClient.deliveries (packages/sdk-swift/Sources/AgentRelaySDK/RelayFacades.swift). One documented caveat: list(state: .deferred) throws RelayError.unsupported because relaycast has no deferred delivery status upstream — a relaycast limitation, not a gap in this SDK surface. Verified against main (86af7c5).

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Generated by Claude Code