mcpb-bundle

mcpb-bundle is a skill for Claude Code, Codex from hybridlabor-api/bdb-dev-optimized-agent-skills. It costs 101 tokens per session (1,081 once invoked), scanned A, a copy of mcpb-bundle, Apache-2.0.

A migration guide for changing a Codex Desktop extension from the older .dxt package format to the newer .mcpb format.

In plain words
What is it for?
It is for checking the package manifest, updating the build process, renaming outputs, and finding remaining .dxt references.
Why use it?
It helps keep the extension buildable and avoids missing old-format names in manifests, scripts, or documentation.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents); mentions Codex.

Good fit It is for checking the package manifest, updating the build process, renaming outputs, and finding remaining .dxt references.

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Install with agentmods
npx agentmods add skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add hybridlabor-api/bdb-dev-optimized-agent-skills --skill mcpb-bundle
Clone the repo
git clone --depth 1 https://github.com/hybridlabor-api/bdb-dev-optimized-agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mcpb-bundle

README.md
[![agentmods](https://agentmods.dev/badge/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle/github.svg)](https://agentmods.dev/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle)
Your own site
<a href="https://agentmods.dev/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle"><img src="https://agentmods.dev/badge/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mcpb-bundle

Your own site · 80×15
<a href="https://agentmods.dev/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle"><img src="https://agentmods.dev/badge/skills/hybridlabor-api/bdb-dev-optimized-agent-skills/mcpb-bundle.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,081 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 91% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00101 $0.01081
Opus 5 $0.00051 $0.00541
Sonnet 5 $0.00020 $0.00216
Haiku 4.5 $0.00010 $0.00108

Measured 9d ago against content hash e385aee4f7c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

mcpb-bundle scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

91% identical to mcpb-bundle — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

mcps/tdmcp/.agents/skills/mcpb-bundle/SKILL.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

tdmcp Desktop bundle: .dxt → .mcpb

Anthropic renamed Desktop Extensions from DXT (.dxt, packer @anthropic-ai/dxt, manifest key dxt_version) to MCPB (.mcpb, packer @anthropic-ai/mcpb, manifest key manifest_version). Legacy .dxt still installs in Codex Desktop, but new directory submissions should ship .mcpb.

What this repo already has

scripts/build-dxt.mjs is already MCPB-aware: it tries @anthropic-ai/mcpb first, falls back to legacy @anthropic-ai/dxt, then to a system zip. The bundle stages manifest.json at the archive root + dist/, recipes/, td/, README.md, LICENSE, package.json, and a production-only node_modules. So the migration is mostly renaming the output + the references, not a rewrite.

dxt/manifest.json currently declares "manifest_version": "0.3" — already the modern MCPB key (not the legacy dxt_version), so the manifest is largely correct.

The migration, concretely

  1. Manifest — verify, don't guess. Before touching manifest_version, check what the installed packer accepts: npx --yes @anthropic-ai/mcpb --help (look for pack / validate). If it ships a validate command, run it against dxt/manifest.json and let it tell you. Only change manifest_version if validation demands it. A wrong value breaks install — this is why we verify rather than assume a number.
  2. Output filenametdmcp.mcpb. In scripts/build-dxt.mjs: change outFile to tdmcp.mcpb and update the log lines (they say .dxt). Keep the packer-preference order and the zip fallback intact — both must still work. Optionally rename the script file to build-mcpb.mjs (update the npm script if you do).
  3. npm scripts (package.json): rename build:dxtbuild:mcpb pointing at the script. Only keep a build:dxt alias if something external depends on the old name (grep first); otherwise replace it cleanly — no compatibility cruft. Check the version script too (it stages dxt/manifest.json).
  4. Reference sweep — change user-facing .dxt.mcpb in: docs/guide/{install,troubleshooting,glossary}.md + their docs/pt/ mirrors, docs/DEPLOYMENT.md, docs/reference/cli.md, scripts/setup.mjs, README.md. Also grep .github/ for any release workflow that builds or uploads tdmcp.dxt / runs build:dxt.
  5. Release-asset URLs. Links to releases/latest/download/tdmcp.dxt point at a published asset. After this change the next release ships tdmcp.mcpb; update those links to .mcpb and record that a new release must be cut so the asset exists (the current v0.3.0 asset is still .dxt). Note this for the human in migration notes.

Read the full file on GitHub · 70 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 70 lines · 101 tokens per session scan A e385aee4f7c6

Subscribe to this mod's changes

mcpb-bundle is a skill published in the GitHub repository hybridlabor-api/bdb-dev-optimized-agent-skills (6 stars, last pushed 4d ago), licensed Apache-2.0. It adds 101 tokens to every session and 1,081 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to mcpb-bundle, differing in 8 lines, and is treated as a copy.