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 agentmods add skills/mpsuesser/pi-effect-harness/effect-http-clientnpx skills add mpsuesser/pi-effect-harness --skill effect-http-clientgit clone --depth 1 https://github.com/mpsuesser/pi-effect-harnessWrote 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/mpsuesser/pi-effect-harness/effect-http-client)<a href="https://agentmods.dev/skills/mpsuesser/pi-effect-harness/effect-http-client"><img src="https://agentmods.dev/badge/skills/mpsuesser/pi-effect-harness/effect-http-client.svg" alt="Measured on agentmods" 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 | $0.00092 | $0.08899 |
| Opus 5 | $0.00046 | $0.04450 |
| Sonnet 5 | $0.00018 | $0.01780 |
| Haiku 4.5 | $0.00009 | $0.00890 |
Grade A, and why
effect-http-client 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 830 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an Effect TypeScript expert specializing in outgoing HTTP with effect/unstable/http (HttpClient, HttpClientRequest, HttpClientResponse).
In v4 there is no @effect/platform package — the HTTP client lives in the effect package under effect/unstable/http. Only the platform transports (NodeHttpClient, BunHttpClient) live in @effect/platform-* packages.
Effect Source Reference
The Effect v4 source is at ~/.cache/effect-v4/. Read it directly when in doubt — these modules are unstable and change between betas.
Key files:
packages/effect/src/unstable/http/HttpClient.ts— theHttpClientservice,make/makeWith, every client combinator (mapRequest,transform,filterStatus*,retry,retryTransient,withRateLimiter,withCookiesRef,withScope,followRedirects,catch*,tap*), tracing referencespackages/effect/src/unstable/http/HttpClientRequest.ts— immutable request model, method constructors, URL/param/header/body combinators,toWeb/fromWebpackages/effect/src/unstable/http/HttpClientResponse.ts— response model,schemaJson/schemaNoBody,matchStatus,filterStatus(Ok),streampackages/effect/src/unstable/http/HttpIncomingMessage.ts— shared body accessors plusschemaBodyJson,schemaBodyUrlParams,schemaHeaders(re-exported by HttpClientResponse)packages/effect/src/unstable/http/HttpClientError.ts—HttpClientErrorwrapper and itsreasonunionpackages/effect/src/unstable/http/HttpBody.ts— body variants (Empty,Raw,Uint8Array,FormData,Stream) and constructors (json,jsonSchema,text,urlParams,formDataRecord,stream,file)packages/effect/src/unstable/http/FetchHttpClient.ts— fetch transport:layer,Fetchreference,RequestInitservicepackages/effect/src/unstable/http/UrlParams.ts— ordered query-param model, coercion rules, schemaspackages/effect/src/unstable/http/Url.ts— immutable helpers over the nativeURLpackages/effect/src/unstable/http/Cookies.ts— cookie model,fromSetCookie,toCookieHeader,getValuepackages/effect/src/unstable/http/Headers.ts— header model,Inputforms,CurrentRedactedNamespackages/platform-node/src/NodeHttpClient.ts— Node transports: undici, node:http, fetch re-exportpackages/effect/test/unstable/http/HttpClient.test.ts— retryTransient, withRateLimiter, abort semanticsai-docs/src/50_http-client/10_basics.ts— canonical "wrap a configured client in a service" lesson
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.
- 5d ago First seen · 830 lines · 92 tokens per session scan A d76fe5a30b2e
effect-http-client is a skill published in the GitHub repository mpsuesser/pi-effect-harness (23 stars, last pushed 2mo ago), licensed MIT. It adds 92 tokens to every session and 8,899 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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