What are the best free alternatives to Caveman?

Security Audit Skill, Codex-X, Qwen Code, Aider, Cline. All are reviewed on Stack Gems in the same category (coding agents); 8 free or open source.

Is there an open-source alternative to Caveman?

Yes: Security Audit Skill (OSS/MIT), Codex-X (OSS/MIT), Qwen Code (Apache-2.0), Aider (Apache-2.0).

Alternatives · Coding Agents

Caveman alternatives (2026)

Caveman: MIT skill surface with BSL engine bits. Use to cut coding-agent token spend; read the BSL boundary before productizing the runtime.

Its Catch: Engine-linked runtime directories (engine/, proxy/, rewriter/, and related) are Business Source License 1.1, not MIT — see LICENSING.md / LICENSE.BSL before embedding or offering a hosted Caveman runtime.

Below: 8 free or free-tier tools from the same category (coding agents), free and open source first, then the closest match by shared tags. Each keeps its own Catch.

1.Security Audit SkillMIT coding-agent skill for multi-phase security audits
Free / OSS · OSS/MIT · 31.2k GitHub stars
VerdictMIT agent security-audit skill. Phased findings vs mcp-security-audit; not a SaaS scanner.
CatchSkill only — not a standalone SaaS scanner. Distinct from mcp-security-audit (awesome-copilot skill for .mcp.json / MCP config audits) and from OWASP ASI checklist skills: this is Cloudflare’s multi-phase code/security audit skill for a coding-agent host. You still need the agent runtime and any scanners the skill shells out to.
2.Codex-XCodex-specific desktop and CLI workspace for visual configuration and MCP skills
Free / OSS · OSS/MIT · 4.2k GitHub stars
VerdictMIT Codex desktop/CLI companion. Handy for visual MCP and skills configuration; audit auth, relay endpoints, and unrestricted templates before trusting it.
CatchVs T3 Code: Codex-X is Codex-specific visual configuration plus MCP/skills, not a broad remote coding environment or an independent coding model. It handles `auth.json`, supports third-party relays, and allows unrestricted prompt templates — review where credentials go, which endpoint receives requests, and what instructions can execute before using a release. Treat relays as a trust decision, not a convenience toggle.
3.Qwen CodeApache-2.0 multi-surface coding agent (Qwen lineage)
Free / OSS · Apache-2.0 · 28.6k GitHub stars
VerdictApache-2.0 multi-surface coding agent when Qwen-lineage open models + Skills/Teams/MCP beat a closed product CLI.
CatchVs Claude Code: paid product CLI. Vs OpenCode / ZCode / fx: other OSS coding agents — Qwen Code is the Qwen-lineage multi-surface agent with open models+framework, not a tiny Zig binary or Earendil harness fork.
4.AiderAI pair programming in your terminal with any model
Free / OSS · Apache-2.0 · 49.6k GitHub stars
VerdictThe open-source terminal coding assistant for API-key purists.
CatchYou are paying per-token at API rates—can exceed subscription costs on heavy use. No managed infrastructure; you are the ops team. Less polished than commercial alternatives.
5.ClineVS Code extension for human-in-the-loop AI coding
Free / OSS · Apache-2.0 · 70.5k GitHub stars
VerdictMaximum control for developers who approve everything.
CatchHuman-in-the-loop means constant interruptions. Large tasks require many approvals. The pace is slower than autonomous alternatives.
6.OpenAI Codex CLIApache-2.0 OpenAI agent: CLI, IDE, app and cloud
Free / OSS · Freemium · 130k GitHub stars
VerdictOpenAI’s answer to terminal agents — open CLI, paid models; budget the plan or the API.
CatchThe CLI is open source, but the models are not free: you pay through ChatGPT plan quotas or API spend. Codex Web runs on OpenAI’s cloud, not on your machine. The install.sh, brew and npm routes are supply-chain choices, so pin a release binary when that matters. Vs Claude Code or OpenCode: this is OpenAI’s first-party agent, tied to ChatGPT plans or OpenAI API keys.
7.Gemini CLIGoogle open-source terminal agent powered by Gemini
Free / OSS · Apache-2.0 · 107k GitHub stars
VerdictGoogle terminal agent. OSS CLI remains, but consumer quota was cut 2026-06-18; Antigravity (agy) is the consumer path. Gemini-bound by design.
CatchGemini-bound lock-in—not model-agnostic like Goose or Crush. Consumer access (free/Pro/Ultra Google login) ended 2026-06-18; enterprise and API keys still work. Don't build on the old Google-login quota path. The OSS CLI remains. Antigravity CLI is the successor, not a 1:1 swap. Preview/nightly channels move fast; pin stable for production workflows. Enterprise path pushes you toward Vertex AI and Google Cloud project setup.
8.CrushCharm-grade TUI coding agent with LSP and mid-session model switch
Free / OSS · Open-Core · 28.7k GitHub stars
VerdictThe beautiful, model-flexible TUI coding agent. Charm quality.
CatchLicensed FSL-1.1-MIT (competing-use restriction; source-available; MIT after two years—not OSI open-source). Pre-1.0 energy—config is migrating from JSON to crushrc Bash. Not a fully autonomous SWE agent like OpenHands; you stay in the loop. Hyper is Charm own model path if you want a subscription. Metrics on by default (DO_NOT_TRACK / CRUSH_DISABLE_METRICS to opt out).

FAQ

What are the best free alternatives to Caveman?: Security Audit Skill, Codex-X, Qwen Code, Aider, Cline. All are reviewed on Stack Gems in the same category (coding agents); 8 free or open source.
What is the catch with Caveman?: Engine-linked runtime directories (engine/, proxy/, rewriter/, and related) are Business Source License 1.1, not MIT — see LICENSING.md / LICENSE.BSL before embedding or offering a hosted Caveman runtime.
Is there an open-source alternative to Caveman?: Yes: Security Audit Skill (OSS/MIT), Codex-X (OSS/MIT), Qwen Code (Apache-2.0), Aider (Apache-2.0).

Caveman alternatives (2026)

FAQ

More