# How I Built a Blog Agent that Writes About Itself

January 16, 2026 4-minute read

I’ve been spending a lot of time “vibe coding” in the Antigravity IDE lately. It’s an incredible flow state—intense, iterative, and fast. But it has a major flaw: the context is ephemeral. Once the session is over, that rich history of decisions, wrong turns, and “aha!” moments is locked away in an opaque, internal format.

I wanted to capture that value. I wanted a system that could take my chaotic coding sessions and distill them into structured, technical blog posts (like the one you’re reading right now).

But getting the data out turned into a much deeper rabbit hole than I expected.

## The Challenge: Check the Database? Link to heading

My first instinct was simple: It’s an Electron app, so there’s probably a SQLite database.

I found it easily enough at `~/Library/Application Support/Antigravity/User/globalStorage/state.vscdb`. But when I opened it up, I hit a wall. The data wasn’t plain text; it was stored in the `ItemTable` under keys like `antigravityUnifiedStateSync.trajectorySummaries` as Base64-encoded strings.

Decoding them revealed raw Protobuf wire formats, not JSON.

### The “Wire-Walking” Dead End Link to heading

I spent a few hours writing a Python script to “wire-walk” the Protobuf data without a schema. I managed to extract some human-readable strings, but it was a mess:

1. Missing Context: I got fragments of text, but the user prompts and cohesive flow were gone.
2. Encryption: The actual conversation files (ending in `.pb`) in `~/.gemini/antigravity/conversations/` were encrypted.

It turns out Antigravity uses Electron’s `safeStorage` API, which interfaces directly with the macOS Keychain. Without the app’s private key (which is hardware-bound), that data is effectively random noise. I even tried using Frida to hook `safeStorage.decryptString()`, but macOS SIP (System Integrity Protection) and code signing shut that down immediately.

I was stuck. I couldn’t decrypt the local files, and I couldn’t parse the database effectively.

## The Breakthrough: Living Off the Land Link to heading

When you can’t break the front door, look for the side entrance. I realized I wasn’t the only one trying to read this state—the official extensions had to do it too.

I started poking around the source code of the `vscode-antigravity-cockpit` extension, specifically a file named `local_auth_importer.ts`. That’s where I found the golden ticket.

The extension doesn’t decrypt the local files. Instead, it reads a specific key from the SQLite database: `jetskiStateSync.agentManagerInitState`.

When I decoded field #6 of this Protobuf structure, I found an `OAuthTokenInfo` message. It contained the user’s active `accessToken` and `refreshToken`.

### Shifting Strategy: Don’t Crack it, Join it Link to heading

This changed everything. I didn’t need to reverse-engineer the local storage encryption; I just needed to impersonate the IDE.

By “piggybacking” on this existing auth mechanism, I could extract a valid OAuth token directly from the local state. But I still needed the endpoints.

Instead of guessing, I opened the Developer Tools inside Antigravity itself (it is Electron, after all). By enabling the Chrome network tracing tools and triggering an export manually, I caught the request in the act.

I saw the exact call to `exa.language_server_pb.LanguageServerService/ConvertTrajectoryToMarkdown`.

It was perfect. By sending a gRPC-over-HTTP request to this endpoint using the stolen token, the server—which does have access to the unencrypted history—returned a perfectly formatted Markdown document of my entire coding session.

## The Architecture: The Blog-Agent Link to heading

Once I had the data extraction solved, building the rest of the “blog-agent” was straightforward. I built a Node.js stack to automate the pipeline:

- Backend: An Express server handles the routing, session imports, and post generation.
- Frontend: A clean EJS interface to list sessions, view summaries, and “publish” them to the filesystem.
- Storage: A local SQLite database (`data/sessions.sqlite`) acts as a cache. (I learned my lesson: always cache your LLM inputs).
- The Brain: I use the OpenAI SDK (pointing to a LiteLLM proxy) to interface with `gemini-3-flash`. I wrote a map-reduce style prompt that first extracts technical decisions from the raw conversation log, then synthesizes them into a narrative.
- Persistence: The final posts are saved with YAML front matter into a `generated_posts/` directory.

## Key Insights Link to heading

- Don’t Fight the OS: Trying to break macOS Keychain/SIP encryption is a losing battle for a weekend project.
- Follow the Tokens: Applications often store auth tokens in less-secure places (like plain SQLite or weaker encryption) than the user content itself.
- Extensions are Open Books: If an app has extensions, their source code is often the best documentation for the internal API.

In a satisfying detailed loop, this very article was generated by the blog-agent itself, analyzing the “vibe coding” session where I built it.

## References Link to heading

- `server.js`: The Express server and API implementation.
- `services/antigravity.js`: The client for the Antigravity gRPC-over-HTTP API.
- vscode-antigravity-cockpit: The extension that leaked the auth logic.