Bullhorn MCP Server
for AI Agents
Connect your AI agent to StackOne's Bullhorn MCP server and give it 67 MCP tools out of the box. Auth, tool execution, and security all managed.
StackOne 
Coverage
67 Agent Actions
Create, read, update, and delete across Bullhorn — and extend your agent's capabilities with custom actions.
Authentication
Agent Tool Authentication
Per-user OAuth in one call. Your Bullhorn MCP server gets session-scoped tokens with zero credentials stored on your infra.
Agent Auth →
Security
Agent Protection
Every Bullhorn tool response scanned for prompt injection in milliseconds — 88.7% accuracy, all running on CPU.
Prompt Injection Defense →
Performance
Max Agent Context. Min Cost.
Free up to 96% of your agent's context window to enhance reasoning and reduce cost, on every Bullhorn call.
Tools Discovery →What is the Bullhorn MCP Server?
A Bullhorn MCP server lets AI agents read and write Bullhorn data through the Model Context Protocol — Anthropic's open standard for connecting LLMs to external tools. StackOne's Bullhorn MCP server ships with 67 pre-built actions, fully extensible via the Connector Builder — plus managed authentication, prompt injection defense, observability, and agent execution runtime. Connect it from MCP clients like Claude Desktop, Claude Code, Cursor, Goose, and VS Code, or from agent frameworks like OpenAI Agents SDK, LangChain, and Vercel AI SDK.
All Bullhorn MCP Tools
Every action from Bullhorn's API, ready for your agent. Create, read, update, and delete — scoped to exactly what you need.
Candidates
- Create Candidate
Create a new candidate record
- List Candidates
Retrieve a list of candidates using search or query
- Get Candidate
Retrieve a specific candidate by ID
- Update Candidate
Update an existing candidate record
- Delete Candidate
Delete a candidate record
Client Contacts
- Create Client Contact
Create a new client contact record
- List Client Contacts
Retrieve a list of client contacts using search or query
- Get Client Contact
Retrieve a specific client contact by ID
- Update Client Contact
Update an existing client contact record
- Delete Client Contact
Delete a client contact record
Client Corporations
- Create Client Corporation
Create a new client corporation (company) record
- List Client Corporations
Retrieve a list of client corporations (companies) using search or query
- Get Client Corporation
Retrieve a specific client corporation by ID
- Update Client Corporation
Update an existing client corporation record
Job Orders
- Create Job Order
Create a new Bullhorn job order — an open role a client is hiring for.
- List Job Orders
Retrieve a list of job orders using search or query
- Get Job Order
Retrieve a specific job order by ID
- Update Job Order
Update an existing job order record
- Delete Job Order
Delete a job order record
Placements
- Create Placement
Create a new placement record
- List Placements
Retrieve a list of placements using search or query
- Get Placement
Retrieve a specific placement by ID
- Update Placement
Update an existing placement record
- Delete Placement
Delete a Bullhorn placement by ID.
Opportunitys
- Create Opportunity
Create a new Bullhorn opportunity — a potential piece of business with a client.
- Get Opportunity
Retrieve a single opportunity by its ID
- Update Opportunity
Update an existing Bullhorn opportunity — for example to advance its pipeline stage or revise its value.
- Delete Opportunity
Delete a Bullhorn opportunity by ID.
Notes
- Create Note
Create a new note record
- List Notes
Retrieve a list of notes using search or query
- Get Note
Retrieve a specific note by ID
- Update Note
Update an existing note record
- Delete Note
Delete a note record
Tasks
- Create Task
Create a new task record
- List Tasks
Retrieve a list of tasks using search or query
- Get Task
Retrieve a specific task by ID
- Update Task
Update an existing task record
- Delete Task
Delete a task record
Appointments
- Create Appointment
Create a new appointment record
- List Appointments
Retrieve a list of appointments using a query. Requires the Calendar & Appointments feature to be enabled in your Bullhorn account.
- Get Appointment
Retrieve a specific appointment by ID
- Update Appointment
Update an existing appointment record
- Delete Appointment
Delete an appointment record
Job Submissions
- Create Job Submission
Submit a candidate to a specific job opening by creating a new job submission record
- List Job Submissions
Retrieve a list of job submissions representing candidate applications to specific job openings
- Get Job Submission
Retrieve comprehensive details about a specific job submission record by its unique identifier
- Update Job Submission
Update an existing job submission record to reflect progress through the hiring pipeline
- Delete Job Submission
Remove a job submission record from active use while preserving it for audit history
File Attachments
- Upload File Attachment
Attach a file to a Bullhorn record, such as adding a CV to a candidate.
- Download File Attachment
Download the binary content of a file attached to a Bullhorn record, such as a candidate's CV.
- Delete File Attachment
Remove a file attachment from a Bullhorn record.
Entity Records
- Create Entity Record
Create a record in any Bullhorn entity, including entities without a dedicated create action.
- Get Entity Record
Retrieve a specific record from any Bullhorn entity by ID
- Query Entity Records
Query records from any Bullhorn entity using a SQL-style where clause — including reference and configuration entities that the search endpoint cannot reach.
- Update Entity Record
Update a record in any Bullhorn entity, including entities without a dedicated update action.
- Delete Entity Record
Delete a record from any Bullhorn entity, where that entity supports deletion.
Other (11)
- List Opportunities
Retrieve a list of opportunities using Lucene search
- List Option Values
Retrieve the selectable option values for a Bullhorn option list, such as Skill, Category, BusinessSector, Specialty, Country or State.
- List All Entity Types
Retrieve a complete list of all available entity types in the Bullhorn system
- Get Entity Field Metadata
Retrieve detailed field definitions and metadata for a specific Bullhorn entity type
- List Searchable Fields
Retrieve the fields that Bullhorn's Lucene search index actually supports for an entity, and confirm whether the entity supports search at all.
- Search Entity
Search for records in any Bullhorn entity using Lucene search syntax or JPQL query
- Search Entity (Large Query)
Search any Bullhorn entity with a Lucene query too long for a URL, by sending the query in the request body.
- Get Multiple Entity Records
Retrieve many records of one Bullhorn entity in a single call by passing a comma-separated list of IDs.
- List Associated Records
Retrieve records related to a specific Bullhorn record — a candidate's notes, a job order's submissions, an opportunity's appointments, and so on.
- Parse Resume To Candidate
Parse a CV/resume file into structured Bullhorn candidate data.
- Mass Update Entity Records
Apply the same field change to many records of one Bullhorn entity in a single request.
Bullhorn AI Agent Use Cases
Connect your AI agent to Bullhorn and help your team scale the recruiting operations they run by hand today.
Use StackOne to connect your AI agent to your ATS and job boards to automate job posting distribution.
ViewUse StackOne to connect your AI agent to your ATS, survey tools, and messaging systems to automate reference checks.
ViewUse StackOne to connect your AI agent to your CRM, email, and calendar tools to automate post-demo follow-up.
ViewSet Up Your Bullhorn MCP Server in Minutes
One endpoint. Any framework. Your agent is talking to Bullhorn in under 10 lines of code.
Agent Frameworks
JSON{
"mcpServers": {
"stackone": {
"command": "npx",
"args": [
"-y",
"mcp-remote@latest",
"https://api.stackone.com/mcp?x-account-id=<account_id>",
"--header",
"Authorization: Basic <YOUR_BASE64_TOKEN>"
]
}
}
}Platform Resources
MCP Code Mode: Keeping Tool Responses Out of Agent Context
Anthropic's code_execution processes data already in context. Custom MCP code mode keeps raw tool responses in a sandbox. 14K tokens vs 500.
11 min
Comparing BM25, TF-IDF, and Hybrid Search for MCP Tool Discovery
Benchmarking BM25, TF-IDF, and hybrid search for MCP tool discovery across 916 tools. The 80/20 TF-IDF/BM25 hybrid hits 21% Top-1 accuracy in under 1ms.
10 min
Indirect Prompt Injection Defense for MCP Tools: A Technical Guide
MCP tools that read emails, CRM records, and tickets are indirect prompt injection vectors. Here's how we built a two-tier defense that scans tool results in ~11ms.
12 min
MCP vs A2A: Architecture, Security, and When to Use Each
MCP vs A2A: what each protocol standardizes, how they differ, their shared security risks including indirect prompt injection, and when to use one, both, or a hybrid architecture.
12 min
MCP vs API: What Hundreds of Connector Builds Taught Us
MCP wraps APIs, it doesn't replace them. After building hundreds of connectors that serve both, here's when each approach wins.
14 min read
Bullhorn MCP Server FAQ
Does StackOne have a Bullhorn MCP server?
Bullhorn MCP server vs direct API integration — what's the difference?
How does Bullhorn authentication work for AI agents?
origin_owner_id.Are Bullhorn MCP tools vulnerable to prompt injection?
What is the context bloat of a Bullhorn agent and how do I avoid it?
Can I limit which actions my Bullhorn agent can access?
Can I create custom agent actions for my Bullhorn MCP server?
When should I NOT use a Bullhorn MCP server?
What AI frameworks and AI clients does the StackOne Bullhorn MCP server support?
Put your AI agents to work
All the tools you need to build and scale AI agent integrations, with best-in-class connectivity, execution, and security.