Developers

The vault, in your tools.

Pull prompts, skills and agent knowledge into context from Claude Desktop, the CLI, or the API.

Connect via MCP

Drop this into your Claude Desktop config. Replace the key with your own.

{
  "mcpServers": {
    "crystal": {
      "command": "npx",
      "args": ["@crystal-ai/cli", "mcp"],
      "env": { "CRYSTAL_API_KEY": "your-key-here" }
    }
  }
}

Use the CLI

No install needed — npx runs the latest.

npx @crystal-ai/cli login
npx @crystal-ai/cli search "cold email" --type prompt
npx @crystal-ai/cli get <id> > my-prompt.md
npx @crystal-ai/cli knowledge search "rag chunking"
npx @crystal-ai/cli knowledge get <id> >> context.md
npx @crystal-ai/cli whoami

Use it often? Install it once instead:

npm install -g @crystal-ai/cli
crystal login

API reference

JSON-RPC 2.0 over POST /api/mcp. Auth with the X-Crystal-Key header.

tool search_vault free

Search prompts and skills. Returns previews only — no full content.

{
  "jsonrpc": "2.0", "id": 1, "method": "tools/call",
  "params": {
    "name": "search_vault",
    "arguments": { "query": "cold email", "type": "prompt", "limit": 10 }
  }
}
tool get_prompt 1 call

Returns the full prompt including full_content. Counts against your monthly quota.

{
  "jsonrpc": "2.0", "id": 2, "method": "tools/call",
  "params": { "name": "get_prompt", "arguments": { "id": "<uuid>" } }
}
tool get_skill 1 call

Same as get_prompt, for skills.

tool search_knowledge free

Search the Agent Knowledge vault — docs written for AI agents to consume. Returns previews only.

{
  "jsonrpc": "2.0", "id": 3, "method": "tools/call",
  "params": {
    "name": "search_knowledge",
    "arguments": { "query": "rag chunking", "limit": 10 }
  }
}
tool get_knowledge 1 call

Returns a knowledge doc's full_content — drop it straight into your agent's context window. Counts against your monthly quota.

{
  "jsonrpc": "2.0", "id": 4, "method": "tools/call",
  "params": { "name": "get_knowledge", "arguments": { "id": "<uuid>" } }
}
tool submit_knowledge write

Creates a knowledge doc (title, short_description, full_content, category, optional tags). Admin keys publish instantly; others go to review.

tool list_categories free

Returns the distinct categories present in the vault.

tool get_creator free

Returns a creator profile and their published prompt + skill previews.

tool list_drops free

Lists the published monthly drops (named releases) with preview metadata.

tool get_drop free

Returns one drop by slug (or month) with its content item previews.

tool account free

Shows your key's plan, monthly usage and tier access.

tool submit_prompt write

Creates a prompt in the vault (title, short_description, full_content, category, tier). Admin keys publish instantly; others go to review.

tool submit_skill write

Creates a skill in the vault (same fields as submit_prompt). Admin keys publish instantly; others go to review.

tool submit_guide write

Publishes a long-form guide (title, summary, markdown body, min_tier_level). Admin keys go live instantly; others submit a draft for review.

Your API key

One key per account. Keep it secret — it carries your quota.

Plans

API access tiers. Join the waitlist — billing opens soon.

Plan Calls / month Tier access Price Action
Dev1,000🟢 Basic $29/mo
Studio10,000🔴 All tiers $99/mo
EnterpriseUnlimited🔴 All tiers $499/mo