One test failure in my code: store_is_closed_on_error. The issue is that the store is only created inside the try block, after getTrace and getTraceMessages succeed. But in the test, getTraceMessages throws, which happens after the store is created (looking at the code flow more carefully)...

Wait, let me re-read my sync.ts code:

try {    const remoteTrace = await api.getTrace(options.externalId);    const remoteMessages = await api.getTraceMessages(options.externalId);
    // ...
    store = runtime.createStore();

The store is only created AFTER the API calls. If getTraceMessages throws, the store was never created, so store?.close() is a no-op. I can either move the store creation before the API calls, or adjust the test to throw after the store exists.

Option 1 makes more sense—I should create the store before the try block or at the start of it, so the finally block can properly close it even if the API calls fail. Though creating it before we know if we need it wastes resources, the safer resource-management pattern is worth it.

Looking at the test setup, it mocks both createStore and createApi. The issue is that getTraceMessages throws before store = runtime.createStore() ever runs, so the store is never created and storeClosed never gets set to true.

The fix is straightforward—I'll move the store creation earlier, before the API calls happen.

The user wants me to consider an additional feature: listing trace IDs for a repo from the web API. This would be useful so that when you're in a git repo, you can ask the API "what traces exist for this repo?" without having to read git notes locally. This could be based on the gitRemoteUrl field that's now stored on traces.

Let me think about this in the context of the git-linked trace discovery feature:

1. Read git notes from local repo → get trace IDs attached to recent commits

2. Also query API by gitRemoteUrl → get all traces for this repo that have been shared

3. Merge the two sets, sync any unknown trace IDs

4. The traces table already has a by_gitRemoteUrl index from PR #253, so I could add a query endpoint like GET /v1/traces?gitRemoteUrl=... to fetch traces for a given repository.

Let me start by understanding the existing codebase structure, particularly the files mentioned in the plan. I need to read several files to understand the patterns before implementing.

Now let me check the PartType values and look at an existing test to understand patterns.

Now I have a thorough understanding of all the pieces. Let me implement the changes:

1. API client (cli/src/services/api.ts) - Add getTrace, getTraceMessages, buildEventFromMessage functions, and update the Api type

2. Sync command (cli/src/commands/sync.ts) - New file

3. Sync options (cli/src/commands/sync-options.ts) - New file

4. CLI entry point (cli/src/index.ts) - Add sync command

5. Tests (cli/src/commands/sync.test.ts) - New file

6. API response shapes - The trace endpoint returns trace metadata like id, external ID, title, and agent details, while the messages endpoint returns an array of message resources with role, content, and model information

. Each message can have multiple parts (text, thinking, tool calls, etc.) that determine how to transform them into events.

7. Reverse transformation logic - I need to map message parts back to their corresponding event types: text content from users becomes UserMessageEvent, assistant text becomes AgentTextEvent, thinking blocks map to AgentThinkingEvent, and tool interactions map to their respective events, with a fallback to textContent if parts aren't available.

8. Extended trace metadata - The TraceDetail response also includes modelName and messageCount fields that I'll need to incorporate.

Now I'm ready to implement the transformation layer using the OpenAPI types from the shared package.

For the Api interface, I need to add getTrace and getTraceMessages methods that the sync command will call directly to fetch remote data, following the same runtime injection pattern used in other commands.

I'm defining local types for RemoteTraceDetail and RemoteMessage that align with the API response structure, then I'll implement the bidirectional transformations between the API format and the event-based format. I need to keep the changes focused, so I'll add getTrace and getTraceMessages directly to the Api type since that's what the sync command expects to call. Now I'm writing the function that converts remote messages into trace events, handling the message parts and building out the event structure.

Writing event conversion logic... Writing the message parsing logic... Setting up the sync command types and runtime... Now I'm fetching the trace metadata and messages from the API, converting those messages into events, and then building a shared URL for the trace.

I'm constructing the trace metadata object with all the relevant details like the agent ID, title, preview from the first event, timestamp, and the shared URL, along with git information if available.

Now I'm persisting this data locally by creating a store, upserting the trace metadata, and replacing the events. If everything succeeds, I'll return a success response with the trace ID and message count. For errors, I'm handling the specific case where the trace isn't found separately, then catching any other failures and returning an appropriate error message. Finally, I'm making sure to close the store in the cleanup phase.

I need to figure out the imports—specifically where buildEventFromMessage comes from in api.ts and how it fits with the forward transform. For the preview field in the trace metadata, I can keep it straightforward by extracting text from the first event in the synced data. I'm also thinking through what the RemoteTraceDetail and RemoteMessage structures look like based on the API responses to make sure I'm mapping the data correctly. Now I'm defining the TypeScript types for the trace and message data structures, starting with the remote trace detail type that includes all the metadata fields like visibility, timestamps, and git information.

Defining the message type...

Now I need to implement the API functions to fetch trace data and messages from the remote service.

Adding these to the Api interface and wiring them up in createApi...

For the sync-options parser...

Setting up the test file...

Now I'm thinking about the getPreview helper function that extracts a preview string from trace events. I'll handle the different event types by returning the first 200 characters of their content, and for tool calls I need to figure out what makes sense to preview.

Actually, I realize I don't need a separate helper function for this—I can just inline the preview extraction logic directly where it's needed.

Now I'm refining the Api type definition and need to be thoughtful about what methods to include, making sure I'm not overcomplicing the interface.

Extending the Api type...

I need to check if adding these new methods will break existing code—the share and list commands create TraceController instances that depend on Api, and while test mocks cast to any so they'll be fine, the actual createApi() implementation will need to provide these methods. Actually, looking at the sync command more carefully, it doesn't need TraceController at all since it works directly with the EventStoreApi and Api without local subscriptions or scanning.

The sync flow is straightforward: fetch the remote trace and messages through the API, convert those messages to TraceEvents, then upsert the metadata and replace the events in the local store before outputting success.

Now I'm ready to implement this.

One thing to verify—the remote agentId comes as a string from the OpenAPI types, but TraceMetadata expects an AgentId type. Since AgentId already includes 'manual' as a valid value and the remote trace's agentId is set when created, I can safely cast it and default to 'manual' if it's undefined.

Writing the implementation now.