The project's README from github.com/1jehuang/jcode. As one markdown file: README.md.
High-performance coding agents.
Run dozens of agents in parallel without melting your machine. More agents, less RAM, no lag.
Website · Docs · OpenAI Ultrafast · SDK · Benchmarks · Screenshots · Install · Contributing
Browse the interactive gallery on jcode.sh.
Inline images |
Deep swarm investigation |
Inline LaTeX |
Info widgets |
# macOS & Linux
curl -fsSL https://jcode.sh/install | bash
Windows installation instructions.
Swarm workers run headless, so this is the number that matters when you fan out agents.
| Tool | First session | Each additional session | Comparison (additional) |
|---|---|---|---|
| jcode | 32.9 MB | ~6.4 MB | baseline |
| OpenCode | 637.1 MB | ~5.9 MB | about the same |
| pi | 84.0 MB | ~79.6 MB | 12.4× more RAM |
| Claude Code | 272.9 MB | ~169.3 MB | 26.5× more RAM |
| Codex CLI | 398.6 MB | ~194.1 MB | 30.3× more RAM |
Each session completes 5 real model turns with tool calls, then total PSS of every process is measured at 1, 5, and 10 concurrent sessions, averaged over two runs. jcode, OpenCode, pi, and Codex CLI used gpt-5.4; Claude Code used Claude Sonnet. Reproduce.
Time until typed text appears on screen, across 10 interactive launches.
| Tool | Time to first input | Comparison |
|---|---|---|
| jcode | 48.7 ms | baseline |
| pi | 596.4 ms | 12.2× slower |
| Codex CLI | 905.8 ms | 18.6× slower |
| OpenCode | 1047.9 ms | 21.5× slower |
| Claude Code | 3512.8 ms | 72.2× slower |
Full numbers on jcode.sh.
Spawn two or more agents in the same repo, and they will automatically be managed by the server to allow native collaboration. When agent A edits a file that agent B has read (code shifting under its feet), the server notifies agent B. Agent B can ignore it if it is not relevant, or it can check the diff to make sure that it doesn't conflict. Each agent has messaging abilities, capable of DMing just one agent, broadcasting to all other agents hosted by the server, or just agents working in that repo. This allows you to spawn multiple sessions in the same repo, and have all conflicts automatically resolved.
Agents are also able to spawn their own swarms autonomously. They have a swarm tool which allows them to spawn in their own teamates to accomplish tasks in parallel. Doing so turns the main agent into a coordinator and the spawned agents into workers. Groups of agents, their messaging channels, their completion statuses, etc are all automatically managed. This can be done headlessly or headed.
agentgrep is jcode's grep tool, built for agents. Each match comes back with the file's structure, like its functions and where they sit, so the agent can understand a file without reading all of it. The harness also adaptively trims results based on what the agent has already seen, so it never pays for the same code twice. This saves a lot of context.
Supports a wide range of providers, including Claude OAuth and OpenAI Codex OAuth.
Jcode is inventing a new form of customizability. One that doesn't limit you to what a plugin or extension can do. Tell your jcode agent to enter self dev mode, and it will start modifying its own source code. Jcode is optimized to iterate on itself. There is significant infrastructure around self development, which allows it to edit, build, and test its own source code, then reload its own binary and continue work in your (potentially many) sessions, fully automatically.