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/cyanheads/reference-data-mcp-server/api-workersnpx skills add cyanheads/reference-data-mcp-server --skill api-workersgit clone --depth 1 https://github.com/cyanheads/reference-data-mcp-serverWhat 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 | $0.00051 | $0.03537 |
| Opus 5 | $0.00026 | $0.01768 |
| Sonnet 5 | $0.00010 | $0.00707 |
| Haiku 4.5 | $0.00005 | $0.00354 |
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 2d 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 — 318 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.
- 2d ago First seen · 318 lines · 51 tokens per session scan A 7979fbfdc182
api-workers is a skill published in the GitHub repository cyanheads/reference-data-mcp-server (1 stars, last pushed 8d ago), licensed Apache-2.0. It adds 51 tokens to every session and 3,537 once invoked, about $0.0003 per session on Opus 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
bun-guides-deployment
Deployment guides for Bun applications on AWS, Docker, Vercel, Fly.io, Railway, and other platforms.
api-workers
Cloudflare Workers deployment using createWorkerHandler from @cyanheads/mcp-ts-core/worker. Covers the full handler signature, binding types, CloudflareBindings extensibility, runtime compatibility guards, and wrangler.toml requirements.
api-workers
Cloudflare Workers deployment using createWorkerHandler from @cyanheads/mcp-ts-core/worker. Covers the full handler signature, binding types, CloudflareBindings extensibility, runtime compatibility guards, and wrangler.toml requirements.
api-workers
Cloudflare Workers deployment using createWorkerHandler from @cyanheads/mcp-ts-core/worker. Covers the full handler signature, binding types, CloudflareBindings extensibility, runtime compatibility guards, and wrangler.toml requirements.
api-workers
Cloudflare Workers deployment using createWorkerHandler from @cyanheads/mcp-ts-core/worker. Covers the full handler signature, binding types, CloudflareBindings extensibility, runtime compatibility guards, and wrangler.toml requirements.
api-workers
Cloudflare Workers deployment using createWorkerHandler from @cyanheads/mcp-ts-core/worker. Covers the full handler signature, binding types, CloudflareBindings extensibility, runtime compatibility guards, and wrangler.toml requirements.