Pedro Müller

Software engineer working on energy and clean-tech.

2 minute read

I like Claude Code. I like staying in one harness, with the same context and the same memory of the session. What I do not like is what happens after the Anthropic subscription window is gone: keep typing on the same tool, and you start burning the expensive path. Usage after the plan limit costs way more than a normal API call to a cheaper model.

Conduit is a small loopback gateway that sits between the agent and the providers so I do not have to care about that mid-flow. Claude Code (and OpenCode if I wire it) still talks Anthropic-shaped HTTP. Conduit decides where the request actually goes.

The problem in one sentence

Subscription first. When the plan says stop, switch the key, not the tool.

Spending tokens on Anthropic after the usage limit is much more expensive than continuing on a DeepSeek API key and finishing the thought. I do not want to open another app, paste context, lose the session, or babysit a model picker. Same harness. Same conversation. Same memories. Even if the agent is mid-thought when the quota trips, the next hop should just cost less.

What it does

While the Claude plan still has capacity, every request goes to Anthropic as usual. Conduit watches for real plan-quota signals, not every random 429. Only the ones that mean your usage window is done. When that fires, it opens a circuit breaker and transparently replays the request on a fallback provider.

Right now my default fallback is DeepSeek V4 Flash. Earlier I used GLM 5.3 the same way. The point of the gateway is that those are just API keys you can swap: pin a provider, change the model map, keep the agent pointed at 127.0.0.1. When the quota window resets, Conduit probes Anthropic again and switches back on its own.

flowchart TD
  Agent[Claude Code / OpenCode] --> GW[Conduit on loopback]
  GW --> Q{Plan quota left?}
  Q -->|yes| AN[Anthropic subscription]
  Q -->|no| FB[Fallback API key]
  FB --> DS[DeepSeek V4 Flash]
  FB -.->|or swap key| GLM[GLM / other]
  AN --> Out[Same session continues]
  DS --> Out
  GLM --> Out

Compatible with Claude Code out of the box (ANTHROPIC_BASE_URL aimed at the gateway). Also wireable for OpenCode (same Anthropic wire protocol, same door). I stay in the agent I already use. The company stays off the surprise invoice. Everyone in that loop spends less when the plan is empty.

Why bother

This is not a new idea. Token spend is geometric: a long agent session after the soft limit is a different price curve than the same session on a cheap flash model. People are already juggling keys by hand. Conduit is just making the juggle automatic and boring.

The code is open source on GitHub. I do believe the direction is right. Use the subscription while it is the good deal. When it is not, keep working on a key that matches the economics, without leaving the harness.

This is how I run my own coding agents, not a vendor pitch. If you are already paying for Claude and then paying again the expensive way when the bar turns red, you already feel the shape of the problem.