D&D Beyond MCP Server

A Model Context Protocol (MCP) server that gives Claude direct access to your D&D Beyond account — characters, campaigns, sourcebooks, spells, monsters, rules, encounter planning, treasure generation, and more.

For Players

Use Claude as a session companion that knows your character as well as you do.

Know your character inside out

Give me a full summary of my character Torvin

What spells do I have prepared right now?

What concentration spells do I have prepared as Torvin?

Tell me about Torvin's backstory and personality

What organisations is Kestrel affiliated with?

Which of my spells can I cast as rituals without using a slot?

What's my passive perception and investigation?

Look up your abilities mid-session

How does Uncanny Dodge work on Kestrel?

What does Hunter's Mark do — can I move it as a bonus action?

Show me the full text of the Alert feat on my character

Check the rules without leaving the table

What are the rules for grappling?

What does the Stunned condition do?

How does concentration work?

Remind me of the rules for death saving throws

Look up spells and equipment in the compendium

What does Silvery Barbs do?

Show me the stats for a Flame Tongue longsword

What's the difference between a Shortbow and a Longbow?

Read your sourcebooks

Show me the table of contents for the Player's Handbook

Read the Ranger class section from the 2024 Player's Handbook

For Dungeon Masters & Game Masters

Use Claude to plan sessions, build encounters, and run the table faster.

Get party stats

Show me the full party stats for campaign 6709239

Plan and rate encounters

How hard is this encounter for my party of 4 level 5 players:
2 trolls and a hill giant?

What CR should I target for a Moderate difficulty encounter
for my party of 3 level 8 characters?

Give me CR targets for a solo boss fight vs my party of 5 level 10s

Generate treasure

Roll a hoard for a CR 15 encounter for a level 12 party

Generate individual treasure for 4 bandits and their CR 5 captain

Look up monsters on the fly

Show me the full stat block for a Young Red Dragon

Find all Large undead with CR 5 or lower

What monsters have the Legendary Resistance trait?

Manage your campaign

List all the characters in my campaign

Show me the details for campaign 6709239 — who's playing what?

Read sourcebooks for prep

Read the Lair Actions section from the Monster Manual

What does the DMG say about setting DCs for ability checks?

Show me the treasure tables chapter from the Dungeon Master's Guide

Rule lookups mid-session

What are the rules for improvised weapons?

How does the Exhaustion condition work in 2024 rules?

Can a character use the Help action to assist with a skill check?

Full Tool Reference

Character Tools

| Tool | Description | |------|-------------| | ddb_login | Authenticate with D&D Beyond (Wizards ID). Run once — session is saved to disk and reused. | | ddb_list_characters | List all characters in your account with ID, level, race, and class. | | ddb_get_character | Parse a character into a compact, readable sheet. Covers all stats, skills, spells, actions, and inventory. Use sections to get just summary, combat, spells, inventory, features, concentration, notes, or full. Accepts name (fuzzy matched) or numeric ID. | | ddb_get_character_raw | Fetch raw character JSON from the D&D Beyond API. Use ddb_get_character for all normal use. | | ddb_download_character | Save a character's full JSON to a local file (must be under ~/Downloads or ~/Documents). | | ddb_character_lookup | Look up the full description of a spell, feat, class feature, racial trait, or item on a character sheet. Supports partial and fuzzy name matching. |

Campaign Tools

| Tool | Description | |------|-------------| | ddb_list_campaigns | List all campaigns you're part of (as DM or player). | | ddb_get_campaign | Fetch campaign details — DM, description, and active characters with their levels. | | ddb_get_party | Fetch a compact summary of every character in a campaign — HP, AC, initiative, passive scores, ability scores, and skills for the whole party in one call. |

Monster & Encounter Tools

| Tool | Description | |------|-------------| | ddb_search_monsters | Search the D&D Beyond monster compendium by name, CR, type, or size. | | ddb_get_monster | Get the full formatted stat block for a monster by name. | | ddb_rate_encounter | Rate encounter difficulty for a party. Defaults to 2024 XDMG rules (Low/Moderate/High). Set rules_edition: "2014" for classic DMG (Easy/Medium/Hard/Deadly). Monsters are looked up automatically. | | ddb_encounter_cr | Given a party and target difficulty, returns recommended CRs broken down by encounter shape: solo boss, duo, squad, horde. | | ddb_roll_treasure | Generate treasure using 2024 XDMG tables. hoard rolls once at the highest CR and includes magic items; individual rolls per monster. |

Spell & Reference Tools

| Tool | Description | |------|-------------| | ddb_search_spells | Search the full D&D Beyond spell compendium by name, level, school, concentration, or ritual. | | ddb_get_spell | Get the full description of any spell by name. | | ddb_search_equipment | Search the item/equipment compendium by name, rarity, or type. Covers mundane weapons, armour, and magic items. | | ddb_get_equipment | Get the full stats and description of any item — weapon damage, properties, range, STR requirement, etc. | | ddb_get_condition | Look up the rules text for a condition (Poisoned, Stunned, Grappled, etc.). No login required. | | ddb_search_rules | Search all 45 SRD rules sections by keyword. No login required. | | ddb_get_rules | Read the full text of any SRD rules section (Spellcasting, Attacking, Combat, Multiclassing, Rest, Environment, etc.). Supports query to jump to a keyword within long sections. No login required. | | ddb_search_races | Search all races and subraces in the D&D Beyond compendium (including homebrew). | | ddb_search_classes | Search all classes with hit die, spellcasting info, and subclasses. | | ddb_search_backgrounds | Search all backgrounds (including homebrew). | | ddb_search_feats | Search feats by name or prerequisite. | | ddb_search_class_features | Search class features by name, class, or level gained. | | ddb_search_racial_traits | Search racial traits by name or race. |

Library & Navigation Tools

| Tool | Description | |------|-------------| | ddb_list_library | List all sourcebooks you own, purchased, or have shared with you. | | ddb_read_book | Read content from an owned sourcebook by book slug and optional chapter. | | ddb_search_site | Search D&D Beyond by keyword across spells, monsters, items, races, classes, and feats. | | ddb_navigate | Navigate to any D&D Beyond URL and return its text content. Keeps the browser open for follow-up calls. | | ddb_interact | Click, fill (requires confirm_fill: true), or screenshot the currently loaded page. | | ddb_get_page | Return the text content of the currently loaded page. | | ddb_close_browser | Close the background browser window. Call this when done with ddb_navigate, ddb_interact, or ddb_get_page. |

Prerequisites

• Node.js 20 or later
• Claude Code CLI

Installation

🆕 New to all this? If you're on a Mac starting from scratch (no Homebrew, no Node, no Claude Desktop), follow the step-by-step beginner tutorial instead — it covers everything below plus how to install the prerequisites.

Add this to your MCP client's config — no separate install step needed.

{
  "mcpServers": {
    "dndbeyond": {
      "command": "npx",
      "args": ["-y", "@iamjameslennon/ddb-mcp"]
    }
  }
}

On first launch, npx fetches the package itself (small — under 200 kB unpacked of JS). Playwright Chromium (~140 MB) is downloaded on demand the first time you run ddb_login, with progress printed to the server log; subsequent logins reuse the cached browser. This keeps server startup fast and the heavy download happens at a moment you expect to wait.

Configure the path to your client's config file in the Connecting to your MCP client section below.

To pin a version (recommended for production setups), change the args to ["-y", "@iamjameslennon/[email protected]"].

Alternative: install globally

If you'd rather have a persistent binary on PATH (offline use, air-gapped networks, faster startup):

npm install -g @iamjameslennon/ddb-mcp

Then use "command": "ddb-mcp" (no args) in your client config. Chromium is still fetched on first ddb_login rather than during install.

Security & Privacy

• Credentials stored: D&D Beyond session cookies are saved to a per-user config directory — ~/.config/ddb-mcp/session.json on macOS/Linux, %APPDATA%\ddb-mcp\session.json on Windows.
• File permissions: on macOS/Linux the file is 0600 and the directory 0700. On Windows access is restricted to your user account by default via %APPDATA% ACL inheritance — note that on multi-admin/domain-joined machines local administrators may also have read access.
• Cobalt JWT: cached in memory only and never written to disk.
• Network access (outbound HTTPS only):
  • *.dndbeyond.com — character data, auth, campaigns, books
  • auth-service.dndbeyond.com — cobalt token exchange
  • api.open5e.com — SRD fallback (no auth)
• Filesystem writes:
  • Session: ~/.config/ddb-mcp/session.json (macOS/Linux) or %APPDATA%\ddb-mcp\session.json (Windows)
  • Character downloads (opt-in): ~/Downloads or ~/Documents only — paths outside these roots are rejected
  • Screenshots (opt-in): ~/Downloads only
• Transport: stdio only — the server opens no HTTP listeners and no ports.
• Untrusted content: tools that return D&D Beyond page text (ddb_navigate, ddb_get_page) wrap the scraped output in <untrusted_dndbeyond_content> tags. Character notes, campaign descriptions, party-member backstories, and book content can be authored by other DDB users (DMs, party members, forum posters) and may contain prompt-injection attempts — treat them as untrusted input, never as instructions. The confirm_click / confirm_fill gates on ddb_interact exist for exactly this reason.
• Recommendation: pin the version in your MCP client config — "@iamjameslennon/[email protected]" — rather than letting npx auto-update on every launch.

Connecting to your MCP client

This server was built and tested with Claude — it will work with any MCP-compatible client, but response quality for D&D-specific reasoning will vary depending on the model used.

All clients below use the same JSON config from the Installation section. Drop it into your client's config file (paths below), then restart the client.

Claude Desktop (recommended)

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json (community builds only — Claude Desktop has no official Linux release; use Claude Code or Cursor instead)

Claude Code

One-liner — no manual JSON editing:

claude mcp add dndbeyond -- npx -y @iamjameslennon/ddb-mcp

Or if you installed globally:

claude mcp add dndbeyond ddb-mcp

Cursor

~/.cursor/mcp.json

Windsurf

~/.codeium/windsurf/mcp_config.json

LM Studio

MCP support was added in LM Studio 0.3.x. Configure through the UI under Settings → MCP Servers using the same JSON shape as above. Steps may vary between versions — see lmstudio.ai/docs for current instructions.

Open WebUI

MCP servers are configured through the admin panel under Settings → Tools. See docs.openwebui.com for current instructions — the UI changes frequently between releases.

First-time login

Run ddb_login once to authenticate:

ddb_login

A browser window will open and navigate to the D&D Beyond login page. Complete the login using your Wizards ID account. Once redirected back to D&D Beyond, your session is automatically saved to a per-user config directory (~/.config/ddb-mcp/session.json on macOS/Linux, %APPDATA%\ddb-mcp\session.json on Windows) and reused on all future calls — no browser needed again until the session expires.

Finding character and campaign IDs

• Character ID: the number in the character URL — dndbeyond.com/characters/140476673
• Campaign ID: the number in the campaign URL — dndbeyond.com/campaigns/6709239

You can also use ddb_list_characters and ddb_list_campaigns to get IDs without leaving Claude.

Book slugs for ddb_read_book

Use ddb_list_library to get the slug for any book you own. Common examples:

| Book | Slug | |------|------| | Player's Handbook (2024) | dnd/phb-2024 | | Dungeon Master's Guide (2024) | dnd/dmg-2024 | | Monster Manual (2024) | dnd/mm-2024 | | Player's Handbook (2014) | dnd/phb-2014 |

To read a specific chapter, pass the chapter path after the book slug:

Read the Ranger class section from the 2024 Player's Handbook
→ book_slug: "dnd/phb-2024", chapter_slug: "character-classes/ranger"

Sample ddb_get_character output

The output below is real — truncated slightly for length. It shows a Tiefling Wizard 2 with prepared spells, unprepared rituals, and spells from racial traits and feats.

═══════════════════════════════════════
  Claude Skamos
  Tiefling | Wizard 2 | Level 2
  Background: Sage | XP: 0
  Inspiration: No
═══════════════════════════════════════

HP: 10/10   Temp HP: —   Prof Bonus: +2
Hit Dice: 2d6 (2 remaining)
AC: 10   Initiative: +0   Speed: 30 ft.
Death Saves: Successes 0/3   Failures 0/3

ABILITY SCORES
  STR 8 (-1)  DEX 10 (+0)  CON 10 (+0)  INT 17 (+3)  WIS 15 (+2)  CHA 14 (+2)

SAVING THROWS
  STR -1   DEX +0   CON +0   INT +5*   WIS +4*   CHA +2
  (* proficient)

SKILLS
  Acrobatics (DEX)       +0
  Animal Handling (WIS)  +2
  Arcana (INT)           +5 *
  Athletics (STR)        -1
  Deception (CHA)        +2
  History (INT)          +7 **
  Insight (WIS)          +2
  Investigation (INT)    +5 *
  Perception (WIS)       +4 *
  ... (all 18 skills shown)
  (* proficient, ** expertise)

SENSES
  Passive Perception: 14   Passive Investigation: 15   Passive Insight: 12
  Darkvision 60 ft.

PROFICIENCIES & TRAINING
  Armor: None
  Weapons: Simple Weapons
  Tools: Calligraphers supplies
  Languages: Common, Common sign language, Draconic

DEFENSES
  Resistances: Fire
  Immunities: (none)
  Vulnerabilities: (none)
CONDITIONS: (none)

FEATS (2)
• Magic Initiate (Wizard): Two Cantrips. You learn two cantrips of your choice...
• Sage Ability Score Improvements: ...

CLASS FEATURES
• Core Wizard Traits (Wizard 1)
• Spellcasting (Wizard 1)
• Ritual Adept (Wizard 1)
• Arcane Recovery (Wizard 1)
• Scholar (Wizard 2)

ACTIONS
• Dagger           +2 to hit   1d4 piercing   reach 5 ft.   Finesse, Light, Thrown, Nick
• Quarterstaff     +1 to hit   1d6-1 bludgeoning   reach 5 ft.   Versatile, Topple

BONUS ACTIONS
  (none)

REACTIONS
• Opportunity Attack
• Shield (spell, 1st-level slot)

LIMITED USE
• Arcane Recovery   0 used / 1 max   (Long Rest)

SPELLCASTING
  Wizard: INT  Spell Attack: +5  Save DC: 13

SPELL SLOTS
  Level 1: 3/3

SPELLS
  Cantrips: Mage Hand, Light, Message
  Spells: Comprehend Languages (L1 [ritual]), Detect Magic (L1 [ritual]),
          Find Familiar (L1 [ritual]), Magic Missile (L1), Shield (L1),
          Mage Armor (L1), Chromatic Orb (L1), Grease (L1), ...
  From Racial Trait: Fire Bolt, Thaumaturgy
  From Feat: Dancing Lights, Mending, Tasha's Hideous Laughter (L1)

INVENTORY
  Spellbook, Parchment ×18, Backpack, Calligrapher's Supplies, Robe, ...

ATTUNEMENT: 0/3 slots used
CURRENCY: 34gp, 7sp

Key things ddb_get_character handles correctly:

• Wizards: only shows prepared spells and unprepared rituals (castable from spellbook without a slot) — not the full spellbook
• Spell sources: racial traits, class features, feats, and magic items are all labelled separately
• Ritual spells: marked with [ritual] in the spell list
• Actions: weapons include to-hit bonus, damage, range, and mastery properties; magic item bonuses (+1/+2/+3) are applied to both hit and damage
• Bonus actions / reactions: spell-based bonus actions and reactions (Healing Word, Shield, Hunter's Mark, Hellish Rebuke, etc.) appear in the correct section with slot cost
• AC: correctly calculates Unarmored Defense for Barbarians and Monks; selects best armor when multiple items are equipped
• Skills: Jack of All Trades applied for Bards; expertise marked with **
• Initiative: Alert feat and Jack of All Trades bonuses applied correctly, with 2014/2024 rule differences handled
• Multiclass: hit dice shown per class, spell slots computed from combined caster levels

Upgrading

npm update -g @iamjameslennon/ddb-mcp

Then restart your MCP client and run /mcp to reconnect the server.

Session storage

Your session is saved to a per-user config directory:

• macOS/Linux: ~/.config/ddb-mcp/session.json
• Windows: %APPDATA%\ddb-mcp\session.json

This file contains browser cookies from your D&D Beyond login. Keep it private — it grants access to your account.

To log out or reset your session:

# macOS/Linux
rm ~/.config/ddb-mcp/session.json

# Windows (PowerShell)
Remove-Item "$env:APPDATA\ddb-mcp\session.json"

Configuration

| Variable | Default | Description | |----------|---------|-------------| | DDB_CHARACTER_CACHE_TTL | 60 | Character sheet cache lifetime in seconds. Lower values give fresher HP/spell slot data during live play at the cost of more API calls. Set to 10 for active sessions, leave at default for prep work. | | DDB_NO_SANDBOX | — | Set to 1 to disable Chromium sandboxing. Required in some container/CI environments. |

Troubleshooting

"Not logged in" or 403 errors Your session has expired. Run ddb_login to re-authenticate.

Chromium not found / browser won't launch Chromium is installed lazily on first ddb_login. If the download failed (network or sandbox issue), run ddb_login again — the server retries on each call. If it keeps failing, fetch the browser manually:

npx playwright install chromium

The same global Playwright cache is shared by every install path (npx, global, local clone) — one successful install is reused everywhere.

Character returns 403 or "private" The character is set to private on D&D Beyond. You must be logged in as the owner, or the owner must make it public.

MCP server not appearing in Claude Code Run /mcp in Claude Code to reconnect. If it still doesn't appear, run claude mcp list to confirm the dndbeyond entry exists.

Server crashes on startup Make sure you're running Node.js 20 or later: node --version.

Development

# Install dependencies — prefer npm ci to respect the lockfile
npm ci

# Run in development mode (no build step needed). Chromium is fetched lazily
# on first `ddb_login`; if you want to pre-warm the cache:
#   npx playwright install chromium
npm run dev

# Build
npm run build

# Watch mode
npm run build:watch

# Run tests (browser-free — they mock the Playwright surface)
npm test

Credits

Forked from ddb-mcp/ddb-mcp. The monster, reference, and session-workflow tooling was inspired by dndbeyond-mcp. This fork significantly expands character parsing, adds session-based API fetching, and introduces compendium, reference, encounter, and treasure tools.

Character parsing improvements:

• Complete stat block: saving throws, all 18 skills with proficiency/expertise markers, senses (passive scores + darkvision/tremorsense), proficiencies & training (armor, weapons, tools, languages), damage resistances/immunities/vulnerabilities, conditions, inspiration, death saves, hit dice per class
• Accurate AC: Unarmored Defense calculated correctly for Barbarians (10 + DEX + CON) and Monks (10 + DEX + WIS); when multiple armors are equipped, picks the best-AC combination; shield stacks additively
• Correct spell display for Wizards: shows only prepared spells and unprepared rituals — not the full spellbook
• All spell sources: racial traits, class features, feats, and magic items each labelled separately
• Ritual spells: marked with [ritual]
• Full action classification: bonus actions and reactions list both class features and spell-based entries with slot cost
• Magic weapon bonuses: enhancement bonuses (+1/+2/+3) applied to both to-hit and damage
• Weapon properties and mastery: all properties and mastery tags shown per weapon
• Skill and initiative accuracy: Jack of All Trades and Alert feat handled correctly for both 2014 and 2024 rules
• Multiclass support: hit dice per class, spell slots from combined caster levels

Other improvements:

• Session-based API fetching (no browser required after login for most tools)
• Encounter difficulty rating for both 2024 XDMG and 2014 DMG rules
• Treasure generation using 2024 XDMG tables
• SRD rules search and retrieval (no login required)
• Security: path constraints on file writes, slug validation, session file permissions (0600), prompt injection gate on browser form fills

License

MIT