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 cyanheads/finnhub-mcp-server --skill api-workersgit clone --depth 1 https://github.com/cyanheads/finnhub-mcp-serverWrote 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/cyanheads/finnhub-mcp-server/api-workers)<a href="https://agentmods.dev/skills/cyanheads/finnhub-mcp-server/api-workers"><img src="https://agentmods.dev/badge/skills/cyanheads/finnhub-mcp-server/api-workers/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/cyanheads/finnhub-mcp-server/api-workers"><img src="https://agentmods.dev/badge/skills/cyanheads/finnhub-mcp-server/api-workers.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 | $0.00051 | $0.03756 |
| Opus 5.5 | $0.00020 | $0.01502 |
| Sonnet 5.5 | $0.00010 | $0.00751 |
| Haiku 4.5 | $0.00005 | $0.00376 |
Grade A, and why
api-workers 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 16d 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.
await worker.fetch(request, r2Env, ctx); This is a copy
100% identical to api-workers — 0 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 — 320 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Overview
@cyanheads/mcp-ts-core/worker exports createWorkerHandler — the Workers entry point. It wraps tool/resource/prompt registries into a per-request McpServer factory that integrates with the Cloudflare Workers runtime.
createWorkerHandler(options)
import { createWorkerHandler } from '@cyanheads/mcp-ts-core/worker';
import { echoTool } from './mcp-server/tools/definitions/echo.tool.js';
import { echoResource } from './mcp-server/resources/definitions/echo.resource.js';
import { echoPrompt } from './mcp-server/prompts/definitions/echo.prompt.js';
import { initMyService } from './services/my-domain/my-service.js';
export default createWorkerHandler({
tools: [echoTool],
resources: [echoResource],
prompts: [echoPrompt],
setup(core) {
initMyService(core.config, core.storage);
},
extraEnvBindings: [['MY_API_KEY', 'MY_API_KEY']],
extraObjectBindings: [['MY_CUSTOM_KV', 'MY_CUSTOM_KV']],
onScheduled: async (controller, env, ctx) => {
// Cloudflare cron trigger handler
},
});
Fresh scaffolds register definitions directly in the entry point as shown above. If your project later adds barrel files for definitions, importing arrays from those barrels is also fine.
Options
| Option | Type | Purpose |
|---|---|---|
tools |
AnyToolDefinition[] |
Tool definitions to register |
resources |
AnyResourceDefinition[] |
Resource definitions to register |
prompts |
PromptDefinition[] |
Prompt definitions to register |
extensions |
Record<string, object> |
SEP-2133 extensions to advertise in server capabilities |
instructions |
string | (env: CloudflareBindings) => string |
Server-level orientation forwarded to the model on every initialize. Resolver form runs inside initializeApp(env) so env-derived text is available (see Workers-specific warnings). Empty string treated as unset. |
setup |
(core: CoreServices) => void | Promise<void> |
Runs after core services are ready, during the first request (lazy init inside the fetch handler) |
extraEnvBindings |
[bindingKey: string, processEnvKey: string][] |
Maps CF string bindings to process.env keys |
extraObjectBindings |
[bindingKey: string, globalKey: string][] |
Maps CF object bindings (KV, R2, D1, AI) to globalThis keys |
onScheduled |
(controller, env, ctx) => Promise<void> |
Cloudflare cron trigger handler |
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.
- 16d ago Changed · +2 lines 95c2a56eac37
- 1mo ago Changed 1690600e0552
- 1mo ago First seen · 318 lines · 51 tokens per session scan A 7979fbfdc182
api-workers is a skill published in the GitHub repository cyanheads/finnhub-mcp-server (1 stars, last pushed 17d ago), licensed Apache-2.0. It adds 51 tokens to every session and 3,756 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to api-workers, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
messari-x402
Access Messari's full API via x402 pay-per-request — no API key needed. Asset data, market metrics, signals, news, fundraising, token unlocks, on-chain networks, and AI chat, all paid with USDC on Base.
add-a-service
Scaffold a new service under services/ in the builders-stack monorepo. Use when something needs its own URL, port, or independent deploy. Covers the package, entrypoint, config, Tilt, deployment registry, and shared small-image build path.
workday-expert
Expert in Workday HCM platform, integrations, custom reports, business processes, calculated fields, and Workday Studio development. Use when the user mentions HR, finance, ERP, cloud, HCM, or Workday integration, or when the task involves Workday Modules, Integration Technologies, Reporting & Analytics, or Custom…
sandy-cli
Run TypeScript scripts in sandboxed microVMs or Docker containers with AWS SDK access via IMDS, through the sandy CLI. Use when investigating AWS resources, running read-only queries, or executing TypeScript automation that needs AWS credentials via shell commands.
massive-flat-files
Foundation skill for bulk historical workflows backed by Massive's S3 flat files. Use whenever you need more than a few hundred ticker-days of trades, quotes, or aggregates. Faster, cheaper, and rate-limit-free compared to REST. Included with any paid Massive plan.
massive-api-patterns
Foundation skill for any REST workflow hitting api.massive.com. Use when calling any /v1, /v2, /v3 endpoint. Covers auth header, rate limit handling, pagination, and the best-price fallback chain. Every other REST-using skill depends on this.