transport-matters

Care for the cargo your coding agent carries.

A provider-neutral context control plane for coding agents. Sits as a reverse proxy in front of Claude, captures every /v1/messages exchange, normalises payloads into an internal representation, runs them through a deterministic curation pipeline, and optionally pauses for manual editing in a schema-aware editor.

No cert install. No system proxy settings. No sudo.

Install

uv tool install transport-matters     # recommended
pipx install transport-matters        # alternative

Or via the bootstrap script (installs uv first if missing):

curl -fsSL https://github.com/littleorgans/transport-matters/releases/latest/download/install.sh | bash

Quick start

# One command: starts the proxy + Claude Code together
transport-matters claude               # in the current directory
transport-matters claude ~/my-project  # in a specific working directory

# Proxy-only (bring your own client)
transport-matters claude --no-claude

# then in another terminal
ANTHROPIC_BASE_URL=http://localhost:8787 claude

From source

For day to day contributor work, install the local checkout as an editable uv tool:

just install-local

Then from any project directory:

transport-matters claude

If you want to run directly from source without installing a tool, run the API project explicitly:

uv run --project api transport-matters claude

From the repo root, just start is equivalent and is the preferred source run entry point.

To validate the packaged artifact instead of the editable checkout, build and install the wheel separately before release.

Open http://localhost:8788 to see the live log, the rules UI, and the breakpoint editor.

What it does

Every /v1/messages request your agent sends gets:

1. Captured — full request and response, logged to ~/.transport-matters/workspaces/{slug}/{hash}/.
2. Curated — a deterministic pipeline applies your rules (strip tools, truncate system parts, rewrite descriptions, drop thinking blocks).
3. Paused (optional) — arm the breakpoint to edit the next request in a schema-aware editor before it forwards upstream.

All visible in a web UI at http://localhost:8788.

Why

A single Claude Code session routinely sends 285 KB payloads: 147 tools, 3 system parts, 5 message turns. Tools alone account for 67% of that. Transport Matters gives you visibility into what's being sent, a pipeline to strip and rewrite it, and a breakpoint to intervene before it hits the API.

Documentation

Full docs, architecture, and contributing guide: https://github.com/littleorgans/transport-matters

License

Apache 2.0. See LICENSE.