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 mpsuesser/pi-effect-harness --skill effect-http-apigit 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-api)<a href="https://agentmods.dev/skills/mpsuesser/pi-effect-harness/effect-http-api"><img src="https://agentmods.dev/badge/skills/mpsuesser/pi-effect-harness/effect-http-api/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/mpsuesser/pi-effect-harness/effect-http-api"><img src="https://agentmods.dev/badge/skills/mpsuesser/pi-effect-harness/effect-http-api.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 | $0.00053 | $0.14123 |
| Opus 5.5 | $0.00021 | $0.05649 |
| Sonnet 5.5 | $0.00011 | $0.02825 |
| Haiku 4.5 | $0.00005 | $0.01412 |
Grade A, and why
effect-http-api 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 1mo 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 — 1,705 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 the HttpApi module for building schema-first HTTP APIs.
Effect Source Reference
The Effect v4 source is available at ~/.cache/effect-v4/. Browse and read files there directly to look up APIs, types, and implementations.
Key reference files:
packages/effect/HTTPAPI.md— canonical HttpApi documentationpackages/effect/src/unstable/httpapi/*.ts— module sourcespackages/effect/typetest/unstable/httpapi/*.tst.ts— type-level contractspackages/platform-node/test/HttpApi.test.ts— comprehensive runtime testsai-docs/src/51_http-server/— server walkthrough with fixturesai-docs/src/50_http-client/— HttpClient walkthrough
Core Imports
// HttpApi modules (definition + building + client + testing)
import {
HttpApi,
HttpApiBuilder,
HttpApiClient,
HttpApiEndpoint,
HttpApiError,
HttpApiGroup,
HttpApiMiddleware,
HttpApiScalar,
HttpApiSchema,
HttpApiSecurity,
HttpApiSwagger,
HttpApiTest,
OpenApi
} from 'effect/unstable/httpapi';
// HTTP primitives (router, server, client, multipart)
import {
FetchHttpClient,
HttpClient,
HttpClientRequest,
HttpClientResponse,
HttpEffect,
HttpRouter,
HttpServer,
HttpServerRequest,
HttpServerResponse,
Multipart
} from 'effect/unstable/http';
// Platform server (Node.js — Bun has @effect/platform-bun/BunHttpServer)
import { NodeHttpServer, NodeRuntime } from '@effect/platform-node';
Architecture Overview
An API is built from three building blocks:
HttpApi
├── HttpApiGroup
│ ├── HttpApiEndpoint
│ └── HttpApiEndpoint
└── HttpApiGroup
├── HttpApiEndpoint
└── HttpApiEndpoint
One definition powers the server, docs, and client — change it once and everything stays in sync.
Critical design rule: API definitions live in their own module/package, separate from server implementations, so clients can import them without pulling in server code or handler dependencies.
Defining Endpoints
HTTP Methods
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.
- 1mo ago First seen · 1,705 lines · 53 tokens per session scan A 1cf2b7e5b70b
effect-http-api is a skill published in the GitHub repository mpsuesser/pi-effect-harness (25 stars, last pushed 4mo ago), licensed MIT. It adds 53 tokens to every session and 14,123 once invoked, about $0.0002 per session on Opus 5.5. 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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