signals.dart: Skill for Claude Code

.agents/skills/jaspr-pre-rendering-and-hydration/SKILL.md

jaspr-pre-rendering-and-hydration is a skill for Claude Code, Codex from rodydavis/signals.dart. It costs 57 tokens per session (1,118 once invoked), scanned A, original, Apache-2.0.

A guide to pre-rendering Jaspr websites and adding browser-side interactivity. Pre-rendering creates page HTML in advance or on the server, while hydration connects interactive behavior in the browser.

In plain words
What is it for?
Use it in static or server-mode Jaspr projects when fetching data, rendering pages, adding client interaction, or organizing server and client entrypoints.
Why use it?
It clarifies which code can run on the server or browser and how to avoid incompatible imports and entrypoint mistakes.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is rodydavis/signals.dart's own configuration. It tells Claude Code and Codex how to work on signals.dart itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything signals.dart configures →

Reuse

Borrowing it

Nothing to install: this file belongs to rodydavis/signals.dart. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/rodydavis/signals.dart/main/.agents/skills/jaspr-pre-rendering-and-hydration/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/rodydavis/signals.dart

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for jaspr-pre-rendering-and-hydration

README.md
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Your own site
<a href="https://agentmods.dev/skills/rodydavis/signals.dart/jaspr-pre-rendering-and-hydration"><img src="https://agentmods.dev/badge/skills/rodydavis/signals.dart/jaspr-pre-rendering-and-hydration/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.

agentmods 80×15 button for jaspr-pre-rendering-and-hydration

Your own site · 80×15
<a href="https://agentmods.dev/skills/rodydavis/signals.dart/jaspr-pre-rendering-and-hydration"><img src="https://agentmods.dev/badge/skills/rodydavis/signals.dart/jaspr-pre-rendering-and-hydration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,118 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00057 $0.01118
Opus 5 $0.00028 $0.00559
Sonnet 5 $0.00011 $0.00224
Haiku 4.5 $0.00006 $0.00112

Measured 11d ago against content hash 202c9e248df6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

jaspr-pre-rendering-and-hydration 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 11d 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.

.agents/skills/jaspr-pre-rendering-and-hydration/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

This skill is relevant for static and server mode Jaspr projects. You can check the mode of a Jaspr project in pubspec.yaml under jaspr: mode: <mode>.

Core Rules for Pre-rendering (SSR/SSG)

Jaspr pre-renders components at request/build-time on the server. Interactive browser features require hydration.

  1. Dual Entrypoints:
    • Server: lib/main.server.dart -> Calls runApp(Document(body: MyApp()))
    • Client: lib/main.client.dart -> Calls runApp(ClientApp())
  2. Library Constraints:
    • Importing: You MUST NOT import dart:js_interop or package:web in any code imported by the server entrypoint.
    • Importing: You MUST NOT import dart:io or dart:ffi in any code imported by the client entrypoint.
    • Using: You can import package:universal_web in shared code, but you MUST wrap any access to its browser APIs inside an if (kIsWeb) check to prevent crashing during server-side rendering.
  3. Interactivity / Hydration: Components are server-rendered by default. To add client interactivity (e.g., event listeners, state, using browser APIs), you MUST annotate a component with @client.

The @client Annotation and ClientApp

When you annotate a component with @client, Jaspr renders its initial HTML on the server and "hydrates" it in the browser.

  • ClientApp() (called in the client entrypoint) automatically looks for and hydrates all @client components that were pre-rendered on the server.
  • Rule: Only the uppermost component of a subtree that needs client interactivity needs to be annotated with @client. Do not annotate child components in that subtree, they will automatically be hydrated as part of the parent.

Passing Data to @client Components

Use parameters of @client components to pass data from the server to the client. These are automatically serialized on the server and deserialized in the browser.

  • Rule 1: All parameters MUST be initializing fields (e.g., const MyClientComponent({required this.title});).
  • Rule 2: All parameters MUST be serializable. They must be primitive types (int, String, double, bool, List, Map) OR custom types that define @encoder and @decoder methods.
    • Parameters MUST NOT be functions, components, or any other non-serializable types.

Read the full file on GitHub · 98 lines

Changes

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.

  1. 11d ago First seen · 98 lines · 57 tokens per session scan A 202c9e248df6

Subscribe to this mod's changes

jaspr-pre-rendering-and-hydration is a skill published in the GitHub repository rodydavis/signals.dart (814 stars, last pushed 2d ago), licensed Apache-2.0. It adds 57 tokens to every session and 1,118 once invoked, about $0.0003 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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