Voiden is an offline API workspace that stores requests, tests, documentation, and reusable API components in plain-text Markdown-based files managed with Git. Developers, QA engineers, and technical writers use it to build, test, document, script, and collaborate on APIs.
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.
npx skills add VoidenHQ/voiden --skill basegit clone --depth 1 https://github.com/VoidenHQ/voidenWrote 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.
[](https://agentmods.dev/skills/voidenhq/voiden/base)<a href="https://agentmods.dev/skills/voidenhq/voiden/base"><img src="https://agentmods.dev/badge/skills/voidenhq/voiden/base/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.
<a href="https://agentmods.dev/skills/voidenhq/voiden/base"><img src="https://agentmods.dev/badge/skills/voidenhq/voiden/base.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00028 | $0.07842 |
| Opus 5.5 | $0.00011 | $0.03137 |
| Sonnet 5.5 | $0.00006 | $0.01568 |
| Haiku 4.5 | $0.00003 | $0.00784 |
Grade A, and why
voiden scanned grade A with 1 finding 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 11d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
### Convert curl to .void How it starts
The opening of the file, as written. The whole thing — 635 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Voiden .void File Format
Read This First
This file covers what every .void file shares: the file structure, the rules, multi-request files, linking between files, and environment variables. Each block type is documented in its own guide file, listed below. The paths are relative to the folder this SKILL.md is in.
Before you write a block, open the guide that documents it and read it in full. Do not write a block from memory, from an example in another guide, or by copying an existing .void file in the project.
- Any HTTP request: read the Voiden REST API guide.
- An API that needs authentication of any kind (a login, a token, an API key, OAuth, a session cookie): read the Voiden Advanced Auth guide before writing the first request. It decides which auth block applies, and when none does.
- Converting a Postman, Insomnia, Bruno, OpenAPI or HAR file: read that importer's guide.
- Assertions, scripts, GraphQL, WebSocket/gRPC, MCP, batch runs: read the matching guide.
If the project has its own script that generates .void files, do not run it in place of writing the files yourself unless the user asks for that.
VOIDEN_EXTENSION_INDEX
Overview
Voiden uses .void files for API testing. Each file uses a hybrid format combining:
- YAML frontmatter for metadata
- Markdown content for documentation
- Custom
voidcode blocks for structured request/response data
File Structure
---
version: __VOIDEN_APP_VERSION__
generatedBy: Voiden app
note: This file is auto-generated by the Voiden app
generatedAt: 2025-01-15T10:30:00.000Z
---
# API Documentation Title
Description and test cases in Markdown...
```void
---
type: request
attrs:
uid: 05119029-b827-45fe-a2cc-55a5f0ba6609
content:
- type: method
attrs:
uid: 35d05fd6-1e12-4f6a-97d5-5c66d59bc61f
method: GET
visible: true
content: GET
- type: url
attrs:
uid: f84b83da-7fe7-415f-baa1-b045adfd7438
content: https://api.example.com/users
---
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.
- 11d ago Changed · +15 lines 5b7347bb9589
- 27d ago Changed · +174 lines 85a0d1896aa0
- 1mo ago First seen · 446 lines · 28 tokens per session scan A b46d55a63126
voiden is a skill published in the GitHub repository VoidenHQ/voiden (1,867 stars, last pushed yesterday), licensed Apache-2.0. It adds 28 tokens to every session and 7,842 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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