Cosmic Companions

Intergalactic Alien Pet Adoption Agency. Browse our catalog of exotic extraterrestrial companions — or let an AI agent find the perfect match for you using WebMCP tools.

Available Companions

All Small Medium Large Gentle Chaotic

For Web MCP Users

Real-time log of WebMCP tool invocations. When an AI agent calls a tool, the call and response appear here.

navigator.modelContext
No tool calls yet. Use an agent to interact with this page.
navigator.modelContext.registerTool()
The core method for the imperative API. You pass it an object with a name, description, inputSchema (JSON Schema for parameters), and an execute function. The browser registers this as a tool that agents can discover and call.
inputSchema — JSON Schema
Defines the parameters the tool accepts using standard JSON Schema. The agent reads this to understand what arguments to pass. Include description fields on each property — this is what the LLM actually reads to decide how to fill in the values.
execute(params) — Returns structured data
This is the big difference from the declarative API. Your execute function receives the agent's parameters, runs your logic, and returns structured data as { content: [{ type: "text", text: "..." }] }. The agent can then reason about the results, chain follow-up calls, or relay findings back to the user in natural language.
Tool chaining pattern
This demo registers three tools that form a natural workflow: search_aliens → get_alien_details → adopt_alien. The agent calls search first, reads the results, picks a candidate, gets more details, and then completes the adoption. Each tool returns data the agent needs for the next step. 
// ── Tool 1: Search Aliens ──
navigator.modelContext.registerTool({
  name: "search_aliens",
  description: "Search the alien pet catalog. Filter by planet of origin, size (small/medium/large), temperament (gentle/playful/chaotic/independent), special ability, maximum price in Galactic Credits, or minimum compatibility score (0-100). Returns a list of matching aliens with basic info. Call get_alien_details for full profiles.",
  inputSchema: {
    type: "object",
    properties: {
      planet: {
        type: "string",
        description: "Planet of origin to filter by (e.g., 'Zorbax-7', 'Krixos Prime', 'Flimora', 'Vexar Minor', 'Grakka', 'Nebula Drift', 'Zynara', 'Paxia Verdant', 'Xelara')"
      },
      size: {
        type: "string",
        enum: ["small", "medium", "large"],
        description: "Size category to filter by"
      },
      temperament: {
        type: "string",
        enum: ["gentle", "playful", "chaotic", "independent"],
        description: "Temperament to filter by"
      },
      ability: {
        type: "string",
        description: "Special ability to search for (e.g., 'telepathy', 'shapeshifting', 'fire breath')"
      },
      max_price: {
        type: "number",
        description: "Maximum adoption price in Galactic Credits"
      },
      min_compatibility: {
        type: "number",
        description: "Minimum compatibility score (0-100)"
      }
    }
  },
  async execute(params) {
    const results = searchAliens(params);
    addLog('search_aliens', params, `Found ${results.length} alien(s)`);
    return {
      content: [{ type: "text", text: JSON.stringify({
        totalResults: results.length, aliens: results
      }, null, 2) }]
    };
  }
});


// ── Tool 2: Get Alien Details ──
navigator.modelContext.registerTool({
  name: "get_alien_details",
  description: "Get the full profile of a specific alien pet, including detailed bio, diet, care requirements, lifespan, warnings, and adoption fee. Requires the alien's ID (e.g., 'zorb-001'). Use search_aliens first to find IDs.",
  inputSchema: {
    type: "object",
    properties: {
      id: {
        type: "string",
        description: "The unique alien ID (e.g., 'zorb-001', 'krix-002')"
      }
    },
    required: ["id"]
  },
  async execute(params) {
    const details = getAlienDetails(params.id);
    addLog('get_alien_details', params,
      details.error || `${details.name} — ${details.species}`);
    if (!details.error) showDetail(params.id);
    return {
      content: [{ type: "text", text: JSON.stringify(details, null, 2) }]
    };
  }
});


// ── Tool 3: Adopt Alien ──
navigator.modelContext.registerTool({
  name: "adopt_alien",
  description: "Begin the adoption process for an alien pet. This navigates to the adoption form page where the adopter's details can be filled in. Requires the alien's ID. Use the submit_adoption_form tool on the next page to complete the adoption.",
  inputSchema: {
    type: "object",
    properties: {
      id: {
        type: "string",
        description: "The unique alien ID to adopt (e.g., 'zorb-001')"
      }
    },
    required: ["id"]
  },
  async execute(params) {
    const a = ALIENS.find(x => x.id === params.id);
    addLog('adopt_alien', params,
      a ? `Navigating to adoption form for ${a.name}...`
        : 'Species not found');
    if (a) window.location.href = `adopt.html?id=${params.id}`;
    return {
      content: [{ type: "text", text: JSON.stringify(
        a ? { status: "navigating_to_form", alien: a.name,
              species: a.species, message: "Redirecting to adoption
              form. Use submit_adoption_form tool on the next
              page to complete the adoption." }
          : { error: "Species not found" }
      ) }]
    };
  }
});