jcode
The next generation coding agent harness to raise the skill ceiling. Built for multi-session workflows, infinite customizability, and performance.
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Installation
# macOS & Linux
curl -fsSL https://raw.githubusercontent.com/1jehuang/jcode/master/scripts/install.sh | bash
Need Windows, Homebrew, source builds, provider setup, or tell your agent to set it up for you? Jump to detailed installation.
Performance & Resource Efficiency
jcode is built to be as performant and resource efficient as possible. Every metric is optimized to the bone, which is important for scaling multi-session workflows. Here we sample a few metrics to show the difference: RAM usage and boot up.
RAM comparison
Time to first frame
| Tool | Time to first frame | Range | Comparison |
|---|---|---|---|
| jcode | 14.0 ms | 10.1–19.3 ms | baseline |
| Antigravity CLI | 383.5 ms | 363.1–415.4 ms | 27.4× slower |
| pi | 590.7 ms | 369.6–934.8 ms | 42.2× slower |
| Codex CLI | 882.8 ms | 742.3–1640.9 ms | 63.1× slower |
| OpenCode | 1035.9 ms | 922.5–1104.4 ms | 74.0× slower |
| GitHub Copilot CLI | 1518.6 ms | 1357.4–1826.8 ms | 108.5× slower |
| Cursor Agent | 1949.7 ms | 1711.0–2104.8 ms | 139.3× slower |
| Claude Code | 3436.9 ms | 2032.7–8927.2 ms | 245.5× slower |
Measured on this Linux machine across 10 interactive PTY launches.
Time to first input
(time until typed probe text appears on the rendered screen; Antigravity uses its internal input-ready log marker because the sign-in screen suppresses probe echo.)
| Tool | Time to first input | Range | Comparison |
|---|---|---|---|
| jcode | 48.7 ms | 30.3–62.7 ms | baseline |
| Antigravity CLI | 383.7 ms | 363.4–415.7 ms | 7.9× slower |
| pi | 596.4 ms | 373.9–955.2 ms | 12.2× slower |
| Codex CLI | 905.8 ms | 760.1–1675.7 ms | 18.6× slower |
| OpenCode | 1047.9 ms | 931.1–1116.9 ms | 21.5× slower |
| GitHub Copilot CLI | 1583.4 ms | 1422.8–1880.0 ms | 32.5× slower |
| Cursor Agent | 1978.7 ms | 1727.3–2130.0 ms | 40.6× slower |
| Claude Code | 3512.8 ms | 2137.4–9002.0 ms | 72.2× slower |
Measured on this Linux machine across 10 interactive PTY launches. Antigravity CLI was unauthenticated for this run; its sign-in screen rendered normally and emitted an internal CLI ready for user input marker, but did not echo the typed probe.
Additional clients / memory scaling
| Tool | Extra PSS per added session | Comparison |
|---|---|---|
| jcode (local embedding off) | ~9.9 MB | baseline |
| jcode | ~10.4 MB | 1.1× more RAM |
| pi | ~76.5 MB | 7.7× more RAM |
| Codex CLI | ~21.6 MB | 2.2× more RAM |
| OpenCode | ~318.4 MB | 32.2× more RAM |
| GitHub Copilot CLI | ~158.1 MB | 16.0× more RAM |
| Cursor Agent | ~157.5 MB | 15.9× more RAM |
| Claude Code | ~212.7 MB | 21.5× more RAM |
| Antigravity CLI | ~86.4 MB | 8.7× more RAM |
jcode v0.9.1888-dev (be386f2)pi 0.62.0codex-cli 0.120.0opencode 1.0.203GitHub Copilot CLI 1.0.24for the 1-session rerun,GitHub Copilot CLI 1.0.27for the 10-session rerunCursor Agent 2026.04.08-a41fba1Claude Code 2.1.86 (Claude Code)Antigravity CLI 1.0.0
Memory (Agent memory)
Jcode embeds each turn/response as a semantic vector. Every turn does queries a graph of memories to efficiently find related memory entries via a cosine similarity check. The embedding hits are fed into the conversat