io.github.cyanheads/pokeapi-mcp-server

---

Overview

Pokémon game data from PokéAPI v2 — Pokémon, moves, abilities, items, and natures, plus computed type-effectiveness matchups. Fetch a denormalized Pokémon dossier in a single call, filter Pokémon by generation, type, pokédex, or egg group, and compute dual-type matchups from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

Tool	Description
pokeapi_get_pokemon	Denormalized Pokémon dossier in one call — stats, types, abilities, evolution chain, sprites, and species data
pokeapi_get_type_matchups	Computed offensive and defensive type effectiveness for a type or Pokémon, with correctly composed dual-type matchups
pokeapi_get_move	Move details — type, damage class, power, accuracy, PP, priority, stat changes, and effect text
pokeapi_get_ability	Ability details — effect text and the Pokémon that have it, with hidden-ability flag and slot
pokeapi_get_item	Item details — effect text, category, cost, fling power, attributes, and common holders
pokeapi_get_nature	Nature details — stat boost/penalty and berry flavor preferences; lists all 25 when called without an identifier
pokeapi_find_pokemon	Filter Pokémon by generation, type, pokédex, or egg group, with name-token matching and pagination

Resources

Resource	Description
pokeapi://pokemon/{identifier}	Pokémon dossier by name or dex number — same payload as pokeapi_get_pokemon without moves
pokeapi://type/{typeName}	Type damage relations — raw multiplier table, offensive and defensive

All resource data is also reachable via tools.

---

Capability reference

pokeapi_get_pokemon _tool

• Accepts a lowercase-hyphenated name or numeric Pokédex number as identifier
• include_moves (default false) adds the learnable-move summary (100–200+ entries); moveCount is always returned regardless
• game_version selects flavor text by game (e.g. "sword", "red"); falls back to the most recent English entry when the version isn't found
• Fans out across /pokemon, /pokemon-species, /evolution-chain, and each /ability in a two-tier parallel fetch, returning stats, types, abilities (with effect text), sprites (including official artwork), evolution chain, varieties, capture rate, growth rate, gender rate, and legendary/mythical flags in one object
• not_found when the identifier resolves to no PokéAPI entry

---

pokeapi_get_type_matchups _tool

• Exactly one of type (type name) or pokemon (name or dex number) is required — providing both or neither is a validation error
• offensiveRelations (super-effective / not-very-effective / no-effect lists) is null for dual-type Pokémon queries, since per-type offense doesn't compose
• defensiveMatchups (weak-to / resists / immune-to) is always populated and correctly composes both types for dual-type Pokémon — immune in either type wins
• composedMultipliers gives the full multiplier (0, 0.25, 0.5, 1, 2, 4) for every attacking type touched, including net-neutral 1× cancellations; a type absent from the map deals 1×
• not_found when the type name or Pokémon identifier doesn't resolve

---

pokeapi_get_move _tool

• Accepts a lowercase-hyphenated move name or numeric ID
• Returns type, damage class, power, accuracy, PP, priority, target, stat changes, and secondary-effect chance, plus full and short English effect text
• include_learners (default false) adds the list of Pokémon that can learn the move
• not_found when the identifier resolves to no move

---

pokeapi_get_ability _tool

• Accepts a lowercase-hyphenated ability name or numeric ID
• Returns full and short English effect text, the generation introduced, and every Pokémon that has the ability, with its hidden-ability flag and slot
• not_found when the identifier resolves to no ability

---

pokeapi_get_item _tool

• Accepts a lowercase-hyphenated item name or numeric ID
• Returns category, Pokédollar cost (0 when not sold in shops), fling power, attributes (holdable, consumable, etc.), sprite URL, effect text, and Pokémon that commonly hold it
• not_found when the identifier resolves to no item

---

pokeapi_get_nature _tool

• identifier (name or ID 1–25) is optional — omit it to return all 25 natures at once (isListAll: true)
• Each entry carries the boosted stat, reduced stat, and liked/disliked berry flavor — all null for the 5 neutral natures
• not_found when a provided identifier resolves to no nature

---

pokeapi_find_pokemon _tool

• Filters — generation, type, pokedex, egg_group — are all optional and combined with AND logic
• query adds strict per-token name matching on top of at least one category filter; query alone with no category filter returns an empty result and a notice
• limit (default 50) and offset (default 0) paginate the filtered set; totalCount reports the full match count before paging
• Each entry carries just id and name, for follow-up pokeapi_get_pokemon calls
• invalid_filter when a generation, type, pokédex, or egg-group name isn't recognized

---

pokeapi://pokemon/{identifier} _resource

• Same payload as pokeapi_get_pokemon with include_moves fixed to false
• identifier is a name or Pokédex number
• not_found when no Pokémon matches the identifier

---

pokeapi://type/{typeName} _resource

• Returns the raw offensive and defensive damage-relation multiplier table for one type
• typeName is one of the 18 canonical Pokémon types
• not_found when the type name doesn't exist in PokéAPI

---

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

PokéAPI-specific:

• Keyless and read-only — no API key, no auth, no configuration required to run
• Graph-walk consolidation — pokeapi_get_pokemon fans out across /pokemon, /pokemon-species, /evolution-chain, and N /ability endpoints in two parallel tiers, returning one object
• Aggressive caching — PokéAPI data is static game data; responses are cached in ctx.state with a configurable TTL (default 6 h) to respect PokéAPI's fair-use policy
• Input normalization — accepts lowercase-hyphenated names or numeric IDs; strips and lowercases user input before fetching
• English-first — effect_entries and flavor_text_entries are always filtered to language.name === 'en'; absent entries surface as null rather than a foreign-language string

Agent-friendly output:

• Dual-type composition — pokeapi_get_type_matchups computes the effective matchup matrix from raw damage relations, so agents get a direct answer rather than raw tables to multiply
• Variant surface — pokeapi_get_pokemon lists all form variants so agents can identify and re-call with specific forms (Alolan, Galarian, Mega, Gigantamax)
• Nullable details — absent move power, accuracy, and effect text remain null in structured results

---

Getting started

Public Hosted Instance

A public instance is available at https://pokeapi.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:

{
  "mcpServers": {
    "pokeapi-mcp-server": {
      "type": "streamable-http",
      "url": "https://pokeapi.caseyjhand.com/mcp"
    }
  }
}

Self-Hosted / Local

No API key required. Add the following to your MCP client configuration file:

{
  "mcpServers": {
    "pokeapi-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/pokeapi-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "pokeapi-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/pokeapi-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "pokeapi-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run", "-i", "--rm",
        "-e", "MCP_TRANSPORT_TYPE=stdio",
        "ghcr.io/cyanheads/pokeapi-mcp-server:latest"
      ]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

• Bun v1.4.0 or higher (or Node.js v24+).
• No API key required — PokéAPI is fully public.

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/pokeapi-mcp-server.git

2. Navigate into the directory:

cd pokeapi-mcp-server

3. Install dependencies:

bun install

4. Configure environment (optional):

cp .env.example .env
# All vars are optional — the server works with defaults

---

Configuration

Variable	Description	Default
POKEAPI_BASE_URL	PokéAPI base URL — override for local mirrors or proxies.	https://pokeapi.co/api/v2
POKEAPI_CACHE_TTL_SECONDS	How long to cache PokéAPI responses (seconds).	21600 (6 h)
POKEAPI_REQUEST_TIMEOUT_MS	Per-request timeout in milliseconds.	10000
MCP_TRANSPORT_TYPE	Transport: stdio or http.	stdio
MCP_SESSION_MODE	HTTP session mode: auto, stateful, or stateless. A meaningful env value overrides the app default. The framework schema defaults to auto, which resolves to stateful. Tenant-scoped caching works in every mode.	stateless
MCP_HTTP_PORT	Port for HTTP server.	3010
MCP_AUTH_MODE	Auth mode: none, jwt, or oauth.	none
MCP_LOG_LEVEL	Log level (RFC 5424).	info
LOGS_DIR	Directory for log files (Node.js only).	<project-root>/logs
OTEL_ENABLED	Enable OpenTelemetry instrumentation.	false

See .env.example for the full list of optional overrides.

Self-hosting for high-volume use

PokéAPI's Fair Use Policy asks consumers to cache aggressively and points high-volume deployments toward running a local instance. This server already caches responses for 6 hours by default (POKEAPI_CACHE_TTL_SECONDS), which covers most workloads. For hosted or batch-heavy deployments, run the official PokéAPI Docker image locally and point POKEAPI_BASE_URL at it — the server switches transparently.

---

Running the server

Local development

• Build and run:

  bun run rebuild
  
  bun run start:stdio
  # or
  bun run start:http
  

• Run checks and tests:

  bun run devcheck   # Lint, format, typecheck, security
  bun run test       # Vitest test suite
  bun run lint:mcp   # Validate MCP definitions against spec
  

Docker

docker build -t pokeapi-mcp-server .
docker run --rm -p 3010:3010 pokeapi-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/pokeapi-mcp-server. Build with --build-arg OTEL_ENABLED=false to omit OpenTelemetry peer dependencies.

---

Project structure

Path	Purpose
src/index.ts	createApp() entry point — registers tools, resources, and inits services.
src/config/	Server-specific env var parsing with Zod (server-config.ts).
src/mcp-server/tools/	Tool definitions (*.tool.ts).
src/mcp-server/resources/	Resource definitions (*.resource.ts).
src/services/pokeapi/	PokeApiService — typed fetch methods, caching, retry, timeout.
tests/	Vitest test suite mirroring src/.

---

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — catch typed upstream errors only to map a declared errors[] contract with ctx.fail(...)
• Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage (and caching)
• Register new tools and resources in the createApp() arrays in src/index.ts
• Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields

---

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

---

License

Apache-2.0 — see LICENSE for details.