CATS MCP Server
FastMCP server for CATS (Complete Applicant Tracking System) API v3 with dynamic toolset loading.
Overview
This MCP server provides access to 228 tools across 17 toolsets covering the complete CATS API v3. The toolset architecture allows agents to load only what they need, optimizing token usage and performance.
Key Features:
π― 228 MCP tools covering all CATS API v3 endpoints (complete coverage)
π¦ 17 toolsets organized by resource type
β‘ Dynamic loading - load only what you need
π Secure - token-based authentication, no hardcoded credentials
π Type-safe - full type hints on all tools
π Well-documented - comprehensive docstrings with examples
π Production-ready - error handling, async/await, tested
βοΈ FastMCP Cloud ready - automatic deployments from GitHub
π Monitoring - health checks and structured logging
Quick Start
Option 1: FastMCP Cloud (Recommended)
Deploy to managed cloud with automatic GitHub deployments:
See FASTMCP_CLOUD_DEPLOYMENT.md for complete guide.
Option 2: Local Development
Architecture
Toolset Organization
DEFAULT Toolsets (105 tools) - Loaded by default:
candidates (44 tools) - Complete candidate management + all sub-resources
jobs (35 tools) - Complete job management, lists, applications, statuses
pipelines (17 tools) - Pipeline workflows and status management
context (3 tools) - Site info, user info, authorization
tasks (5 tools) - Task management
RECRUITING Toolsets (106 tools) - Optional:
companies (48 tools) - Complete company management + phones, departments, lists, statuses, thumbnails
contacts (42 tools) - Complete contact management + lists, statuses, thumbnails
activities (6 tools) - Activity tracking (calls, meetings, emails)
portals (8 tools) - Career portals and applications
work_history (3 tools) - Employment history management
DATA & CONFIG Toolsets (22 tools) - Optional:
tags (2 tools) - Global tag management
webhooks (4 tools) - Webhook subscriptions with 24+ event types
users (2 tools) - User and permissions management
triggers (2 tools) - Automated trigger information
attachments (4 tools) - File management + AI resume parsing
backups (3 tools) - Database backup management
events (5 tools) - Calendar events and scheduling
Token Efficiency
Agents load only needed toolsets, dramatically reducing token usage:
Toolsets | Tools Loaded | Use Case |
Default | 105 (~46%) | Core recruiting |
candidates,companies | 92 (~40%) | Candidate sourcing |
all | 228 (100%) | Complete API coverage |
Installation
1. Setup
2. Configure
Create .env file:
3. Add to Claude Desktop
Edit ~/.claude/config.json:
Usage
Command Line
Common Combinations
API Coverage
Complete Tool List
Candidates (44 tools) - Complete Coverage
Main: list, get, create, update, delete, search, filter, authorize
Sub-resources: pipelines, activities, attachments, custom fields (with details), emails (full CRUD), phones (full CRUD), tags, work history (full CRUD), lists (full CRUD), thumbnails
Jobs (35 tools) - Complete Coverage
Main: list, get, create, update, delete, search, filter
Sub-resources: activities, attachments, custom fields (with details), tags, statuses (full management)
Job lists: full CRUD + item management
Applications: list, get details, get fields
Pipelines (17 tools) - Complete Coverage
Main: list, get, create, update, delete, filter
Workflows: list workflows, get workflow, list workflow statuses, get workflow status
Status management: get history, change status
Companies (48 tools) - Complete Coverage
Main: list, get, create, update, delete, search, filter
Sub-resources: activities, attachments, contacts, custom fields (with details), pipelines, tags
Advanced: phones (full CRUD), departments (full CRUD), lists (full CRUD), statuses, thumbnails
Contacts (42 tools) - Complete Coverage
Main: list, get, create, update, delete, search, filter
Sub-resources: activities, attachments, custom fields (with details), emails (full CRUD), phones (full CRUD), pipelines, tags
Advanced: lists (full CRUD), statuses, thumbnails
Activities (6 tools)
list, get, update, delete, search, filter
Types: email, meeting, call_talked, call_lvm, call_missed, text_message, other
Portals (8 tools)
list, get, list jobs
submit application, publish/unpublish jobs
registration forms
Work History (3 tools)
get, update, delete
Tags (2 tools)
list, get
Webhooks (4 tools)
list, get, create, delete
24+ event types with HMAC-SHA256 verification
Users (2 tools)
list, get
Access levels: read_only, edit, admin
Triggers (2 tools)
list, get
Attachments (4 tools)
get, delete, download
parse_resume - AI-powered resume parsing
Backups (3 tools)
list, get, create
Options: attachments, emails
Events (5 tools)
Full CRUD: list, get, create, update, delete
Attendees, virtual meeting URLs, calendar integration
Context (3 tools)
get_site, get_me, authorize_user
Tasks (5 tools)
Full CRUD with priority, assignments, due dates
Development
File Structure
Testing
Troubleshooting
Common Issues
"CATS_API_KEY not configured"
Set in
.envor export as environment variable
"Module not found: toolsets_*"
Ensure all three toolset files exist
Rate Limiting (500 req/hour)
Monitor
X-Rate-Limit-RemainingheaderImplement backoff on 429 errors
401 Unauthorized
Verify API v3 key (not v2)
Check key permissions
Resources
CATS API: https://docs.catsone.com/api/v3/
FastMCP: https://gofastmcp.com/
MCP Protocol: https://modelcontextprotocol.io/
License
Provided as-is for CATS API v3 integration. Follow CATS API terms of service.
Changelog
2025-12-16 - v2.0.0
Complete API coverage: Expanded from 164 to 228 tools (+64 endpoints)
Added missing critical features:
Lists management (candidate/job/company/contact lists - 32 endpoints)
Status management (job/company/contact statuses - 9 endpoints)
Thumbnails (candidate/company/contact - 6 endpoints)
Custom field details (3 endpoints per resource - 9 total)
Work history CRUD (3 endpoints)
Company phones (5 endpoints)
Company departments (5 endpoints)
Bug fixes:
Fixed
filter_candidatespagination (moved to JSON body)Fixed
filter_jobspagination (moved to JSON body)
Now covers 100% of documented CATS API v3 endpoints
2025-01-26 - v1.0.0
Initial release with toolset architecture
164 tools across 17 toolsets
Dynamic loading via CLI/environment
~82% CATS API v3 coverage
Production-ready