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 apideck-libraries/api-skills --skill fourthgit clone --depth 1 https://github.com/apideck-libraries/api-skillsWrote 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/apideck-libraries/api-skills/fourth)<a href="https://agentmods.dev/skills/apideck-libraries/api-skills/fourth"><img src="https://agentmods.dev/badge/skills/apideck-libraries/api-skills/fourth/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/apideck-libraries/api-skills/fourth"><img src="https://agentmods.dev/badge/skills/apideck-libraries/api-skills/fourth.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 | $0.00067 | $0.01932 |
| Opus 5.5 | $0.00027 | $0.00773 |
| Sonnet 5.5 | $0.00013 | $0.00386 |
| Haiku 4.5 | $0.00007 | $0.00193 |
Grade A, and why
fourth 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 15d 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.
curl 'https://unify.apideck.com/connector/connectors/fourth' \ This is a copy
83% identical to acerta — 87 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.
How it starts
The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Fourth (via Apideck)
Access Fourth through Apideck's HRIS unified API — one of 58 HRIS connectors that share the same method surface. Code you write here ports to BambooHR, Workday, Deel and 54 other HRIS connectors by changing a single serviceId string. Apideck handles auth, pagination, rate limiting, and retries so you don't write per-tenant Fourth plumbing.
Beta connector. Fourth is currently in beta on Apideck. Expect partial resource coverage and occasional mapping gaps. Always verify coverage (see below) and fall back to the Proxy API for unsupported operations.
Quick facts
- Apideck serviceId:
fourth - Unified API: HRIS
- Auth type: basic
- Status: beta
- Gotchas: page
- Fourth docs: https://www.fourth.com
- Homepage: https://www.fourth.com/
At a glance
- Implementation difficulty: involved — Credentials Only Via a Mutual Fourth Customer + Basic Auth With Vendor-Issued Keys
- Vendor partnership required: no (developer portal) — No partner programme to join.
- Apideck-managed credentials: not available — Fourth issues credentials against each customer account.
- Account type required: A Fourth UK Employee API account, with Fourth as employee master record and payroll system.
- Consumer access level: A Fourth account admin able to request API keys from Fourth.
- Sandbox: available (signup) — Test credentials come from the Fourth consultant assigned to the mutual customer's project; not self-serve.
- Rate limits: No numeric limit published; Fourth advises at most one retry a minute on 5xx errors.
- Authentication: Organisation ID, API key and secret key, all issued by Fourth.
- Webhooks: Virtual webhooks - employee created and updated events
Important to know:
- Fourth does not sell or issue API access directly: live credentials are linked to a customer account, so a mutual Fourth customer requests them, and Fourth does not publish the API host, so you also obtain it from Fourth.
- This connector runs on Fourth's UK Employee API, so it serves Fourth customers in the United Kingdom only.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 15d ago Changed · +22 lines 2494d3f85000
- 1mo ago First seen · 131 lines · 67 tokens per session scan A a2f61dddbc53
fourth is a skill published in the GitHub repository apideck-libraries/api-skills (5 stars, last pushed yesterday), licensed Apache-2.0. It adds 67 tokens to every session and 1,932 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 83% identical to acerta, differing in 87 lines, and is treated as a copy.
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