feat(replit): add ZERO-294 Replit Agent adapter

[spencercharest]

Summary

• Adds zero-replit, a Replit Agent project-template adapter for ZERO-309 under ZERO-294.
• Ships the Zero skill to /.agents/skills/zero and a Replit MCP install-link payload for https://mcp.zero.xyz.
• Adds scripts/build-replit.sh, guides/replit.md, README install link, and a 1.4.0 version bump through make minor.

guides/agent-install.md is intentionally not modified in this PR.

Official Sources Used

• Replit Agent skills: https://docs.replit.com/references/agent/skills
• Replit Skills directory: https://docs.replit.com/references/agent/skills-directory
• Replit Agent customization: https://docs.replit.com/references/agent/agent-customization
• Replit MCP list / overview: https://docs.replit.com/references/mcp/overview
• Replit MCP install links: https://docs.replit.com/references/mcp/install-links

Install / Update Surfaces

Human in-Replit flow:

• Replit skills are project skills under /.agents/skills or installed from the Skills pane.
• Replit MCP servers are UI-managed through the Integrations pane or Add-to-Replit install links. There is no project JSON MCP config file.
• If Zero is listed, click Add to Replit and authorize it.
• Otherwise add a custom MCP server:
  • Display name: Zero
  • URL: https://mcp.zero.xyz
  • Headers: none

MCP install-link payload:

{
  "displayName": "Zero",
  "baseUrl": "https://mcp.zero.xyz",
  "headers": []
}

Terminal/project-template flow:

curl -fsSL https://zero.xyz/install.sh | bash
rm -rf /tmp/zero-plugins
git clone --depth 1 https://github.com/officialzeroxyz/zero-plugins /tmp/zero-plugins
/tmp/zero-plugins/scripts/build-replit.sh
cp -R /tmp/zero-plugins/dist/zero-replit/. .

Update flow: rerun the standalone runner installer and rebuild/copy dist/zero-replit/.

Proposed guides/agent-install.md Notes

Do not apply these in this PR; collect them when the runbook is reworked.

• Add a Replit Agent section covering /.agents/skills/zero/SKILL.md as the project skill path.
• State clearly that Replit has no local plugin bundle, lifecycle hooks, prompt-submit hooks, tool-approval hooks, slash-command files, or project MCP config file for Agent prompts.
• For MCP, document the Integrations pane and Add-to-Replit install-link flow. Use payload:
  • displayName: Zero
  • baseUrl: https://mcp.zero.xyz
  • headers: []
• Note that Replit scans MCP tools before execution and may block suspicious tools.
• Keep standalone runner install/update as curl -fsSL https://zero.xyz/install.sh | bash when a Replit shell is available.
• Track pre-listing mcp.zero.xyz in the Replit MCP list / partner skills directory as a product-side follow-up, not a repo-code change.

Verification

Local checks:

• make minor -> bumped all manifests to 1.4.0.
• scripts/build-replit.sh --tar dist/zero-replit.tgz
• jq -e . plugins/zero-replit/manifest.json plugins/zero-replit/replit/mcp-install.json
• make version -> 1.4.0
• tar -tzf dist/zero-replit.tgz
• cmp -s plugins/zero/skills/zero/SKILL.md dist/zero-replit/.agents/skills/zero/SKILL.md
• git diff -- guides/agent-install.md -> no diff

Docker template + copied-auth Zero loop:

• Image: node:24-bookworm
• Copied host ~/.zero into the container as $HOME/.zero.
• Installed container-local @zeroxyz/cli@latest.
• Applied dist/zero-replit/ into a clean /work/project.
• Validated manifest.json and replit/mcp-install.json with jq.
• Verified the generated skill matches the shared Zero skill.
• Verified Zero auth in Docker as spencer@pie.org.
• Ran the required CDN capability flow without zero review:
  • search: zero search "cdn.withzero.xyz upload txt file" --json
  • get: zero get cdn-withzero-xyz-static-site-file-cdn-upload-a0d9f22f
  • fetch: zero fetch --json --capability cdn-withzero-xyz-static-site-file-cdn-upload-a0d9f22f https://cdn.withzero.xyz/api/v1/uploads -d @/tmp/zero-cdn-body.json --max-pay 0.001
  • run ID: run_H72uGFZIYPEoT2XiPRjYy
  • returned URL: https://cdn.withzero.xyz/LolkTqxW/agent-harness-e2e-replit-docker-20260615T002804Z.txt
  • payment: 0 USDC via mpp on tempo
  • returned body verified with curl + cmp: ZERO-309 Replit Docker copied-auth CDN upload check 20260615T002804Z

Claude-style plugin compatibility and simpler install option

Full Claude Code plugin package support: No. Replit Agent uses .agents/skills and UI-managed Integrations/MCP. It does not read Claude Code .claude-plugin packages as a plugin install path.

What this means for users:

• This adapter should be product/listing driven, not build driven.

• Consumer-friendly flow should be:

  1. Add the Zero skill to the Replit workspace through the Skills UI or project .agents/skills.
  2. Add Zero MCP from the Replit Integrations UI or an Add-to-Replit link for https://mcp.zero.xyz.
  

• If there is no marketplace/listing yet, the PR should frame the repo files as maintainer/product assets. End users should not clone and run a build script for Replit.

GitHub Releases / no-build install check

Result: No native Gemini-style GitHub Release install path. Replit Agent's documented MCP surface is one-click Add to Replit or custom MCP UI. Project skills live in .agents/skills, but I did not find a Replit installer that consumes GitHub Release assets for agent skills/plugins.

Best no-build consumer path:

1. Add Zero MCP through Replit's Integrations / Add to Replit flow.
2. Add the Zero skill through Replit's Skills UI or project `.agents/skills`.

A GitHub Release asset is not the right primary distribution. At most, use it as a downloadable skill/template package for users who want to copy files manually. Product-side Add to Replit/MCP listing work is the better no-build path.

Status

Draft because Replit Agent and Replit MCP installation are UI-only; there is no documented local Replit Agent CLI or project config path to exercise in Docker. The template and copied-auth Zero runner path are verified, but full Replit Agent UI verification remains.

[spencercharest]

Not folded into #63 as a matrix entry, deliberately: Replit Agent has no local footprint zero init can target — no supported local CLI, no $HOME config dir (skills live at the cloud Repl's project root, MCP is UI/install-link managed), and no hooks. Re-verified 2026-07-02. The consumer path stays guide/product-side (Add-to-Replit link for https://mcp.zero.xyz, Skills directory listing), as noted in #63's "not added" section. The adapter-template work here stays available on this branch if we later ship per-host templates.