Swift SDK: threads (threaded conversations) (TS participant SDK parity)

[willwashburn]

What the TS participant SDK provides

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

• get(messageId, options?): Promise<RelayThread> — fetch a threaded conversation and its replies.
• reply(input): Promise<RelayMessage> — post a reply into a thread.

What the Swift AgentRelaySDK lacks

The Swift AgentClient (AgentRelayClient.swift) has no thread surface. It can post/dm and stream events, but there is no way to fetch a thread or post a threaded reply to a specific parent message.

Proposed Swift API sketch

public struct RelayThread: Decodable, Sendable { /* root + replies */ }

extension AgentClient {
    public func thread(_ messageId: String, limit: Int? = nil) async throws -> RelayThread
    public func reply(to messageId: String, message: String) async throws -> RelayMessage
}

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 threads natively.

Relaycast's Relaycast product provides AgentClient.thread(_ id:, options:) and .reply(_ id:, text:, options:), with a workspace-level equivalent in RelayMessagesService.thread(_: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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Generated by Claude Code

[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). RelayThreads provides get(_:limit:before:after:) and reply(to:text:), exposed as AgentClient.threads (packages/sdk-swift/Sources/AgentRelaySDK/RelayFacades.swift, AgentRelayClient.swift), delegating to the relaycast engine's thread/reply. Verified against main (86af7c5).

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Generated by Claude Code