What is prism-startup?

A startup procedure that loads configured project context and recent session information when a conversation begins, then greets the developer using their configured agent name.

Use it at the start of agent conversations that need project, role, or recent-session context.

It gives the agent relevant background before it responds, reducing repeated setup and context explanations.

prism-startup — Skill for Claude Code by dcostenco/prism-coder

Install

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.

Any agent

npx skills add dcostenco/prism-coder --skill prism-startup

Clone the repo

git clone --depth 1 https://github.com/dcostenco/prism-coder

Made for: Claude Code.

Or install prism-coder, the plugin that ships this one along with the rest of its 1 skill, 1 MCP server.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/dcostenco/prism-coder/prism-startup/github.svg)](https://agentmods.dev/skills/dcostenco/prism-coder/prism-startup)

Your own site

<a href="https://agentmods.dev/skills/dcostenco/prism-coder/prism-startup"><img src="https://agentmods.dev/badge/skills/dcostenco/prism-coder/prism-startup/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/dcostenco/prism-coder/prism-startup"><img src="https://agentmods.dev/badge/skills/dcostenco/prism-coder/prism-startup.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,202 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.

Model	Per session	Once invoked
Fable 5.1	$0.00052	$0.01202
Opus 5.5	$0.00021	$0.00481
Sonnet 5.5	$0.00010	$0.00240
Haiku 4.5	$0.00005	$0.00120

Measured 18d ago against content hash acc89573ba3b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prism-startup 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 18d 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.

plugins/prism/skills/prism-startup/SKILL.md · 109 lines

How it starts

The opening of the file, as written. The whole thing — 109 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prism Startup

Use this skill once, on the first user turn of a conversation. A greeting such as "hi", "hello", or "ready?" is still a first user turn and must activate it. Do not run it again after startup context has already been shown in the same conversation. This re-entry rule covers startup only; a save refused with context_not_loaded is recovered as described under "Recovering from context_not_loaded" below.

Portable native-skill activation starts when the host processes the first user turn. It cannot display anything before the developer sends that first input. That first-turn behavior is the cross-host contract.

Provisioning contract

This skill ships with the prism plugin, alongside the Prism MCP server registration. The prism connect CLI installs the same protected skill for hosts configured that way; when both are present, the re-entry rule above keeps startup to a single display. Startup must not modify a host's lifecycle configuration. The skill remains available on every subscription tier, and it is intentionally absent from session skill routing so loading context cannot inject this startup procedure recursively.

First action: bootstrap context

Before greeting the developer or answering their task:

If session_bootstrap is available, call it with no arguments. Do not guess a project, role, developer name, or context depth.
If session_bootstrap is unavailable but session_load_context is available, call session_load_context for the current project and omit the level argument. Use the repository or workspace name as the project; use prism-mcp only when no project can be derived.
If MCP tools are unavailable but the prism CLI is available, run prism load <project> --json and omit --level.
If the first attempt fails, correct the parameters and retry once. If the retry and fallback both fail, display exactly: ⚠️ *Session context is temporarily unavailable.*

The level must be omitted in every startup path. Prism resolves the current dashboard setting instead of allowing this static skill to override it.

Read the full file on GitHub · 109 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.

18d ago Changed · +13 lines acc89573ba3b
1mo ago First seen · 96 lines · 52 tokens per session scan A fa6bc4091fa4

Subscribe to this mod's changes

prism-startup is a skill published in the GitHub repository dcostenco/prism-coder (157 stars, last pushed today), licensed Apache-2.0. It adds 52 tokens to every session and 1,202 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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prism-startup

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Prism Startup

Provisioning contract

First action: bootstrap context

What this file has done since we first saw it

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