Why I quit SaaS AI observability tools and built a local proxy instead

A developer built ccglass, a local loopback reverse proxy for coding agents, after finding that SaaS AI observability tools like Langfuse and Helicone do not work with native CLIs such as Claude Code and Codex. The proxy intercepts HTTPS calls directly, bypassing the HTTP_PROXY environment variable issue, and provides a dashboard showing token usage and cache hit rates.

I've been using Langfuse and Helicone for the last 6 months. They're great products. Their teams are sharp. But they don't work for coding agents. | Tool | Architecture | Works for coding agents? | |---|---|---| | Langfuse | SDK + async upload to SaaS | ❌ Need to instrument the agent | | Helicone | HTTPS proxy via HTTP PROXY | ❌ CLIs ignore HTTP PROXY | | Datadog LLM Obs | APM agent | ❌ Same problem | ccglass | Local loopback reverse proxy | ✅ Yes | The reason: Claude Code, Codex, OpenCode, Kimi, etc. are native CLIs Node, Rust, Go . They make HTTPS calls directly to the API endpoint. They do not respect HTTP PROXY environment variables. So the standard observability play — "just point your SDK at our proxy" — doesn't work. The agent isn't using a library that knows to call your endpoint. I needed something that would: http://127.0.0.1 I built it. It's called ccglass https://github.com/jianshuo/ccglass . It does those 5 things. Nothing else. bash $ npm i -g ccglass $ ccglass claude → starts proxy on http://127.0.0.1:8123 → overrides ANTHROPIC BASE URL to point at it → spawns claude → opens dashboard at http://127.0.0.1:8123 The dashboard shows: If you use a coding agent heavily, and you don't know which of your prompts are 4,000 tokens of accidental repetition, you're leaving money on the table. The first time I saw my own cache hit rate 38% — meaning I was re-sending the same system prompt 38% of the time and not knowing it , I had a "wait, that's literally me paying for nothing" moment. Try it once. The data is eye-opening. 🔗 GitHub: https://github.com/jianshuo/ccglass https://github.com/jianshuo/ccglass