Oyster HR MCP Server
for AI Agents
Connect your AI agent to StackOne's Oyster HR MCP server and give it 59 MCP tools out of the box. Auth, tool execution, and security all managed.
StackOne 
Coverage
59 Agent Actions
Create, read, update, and delete across Oyster HR — and extend your agent's capabilities with custom actions.
Authentication
Agent Tool Authentication
Per-user OAuth in one call. Your Oyster HR MCP server gets session-scoped tokens with zero credentials stored on your infra.
Agent Auth →
Security
Agent Protection
Every Oyster HR 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 Oyster HR call.
Tools Discovery →What is the Oyster HR MCP Server?
A Oyster HR MCP server lets AI agents read and write Oyster HR data through the Model Context Protocol — Anthropic's open standard for connecting LLMs to external tools. StackOne's Oyster HR MCP server ships with 59 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 Oyster HR MCP Tools
Every action from Oyster HR's API, ready for your agent. Create, read, update, and delete — scoped to exactly what you need.
Webhooks
- List Webhooks
Retrieve all webhook endpoints registered for the authenticated organization
- Delete Webhook
Delete a webhook endpoint by ID
Engagements
- List Engagements
Retrieve a paginated list of engagements (employees and contractors)
- Get Engagement
Retrieve details of a specific engagement by ID
Contract Changes
- Create Contract Change
Create a new contract change request for an engagement
- List Contract Changes
Retrieve all contract change requests across engagements
- Get Contract Change
Retrieve details for a specific contract change request
Time Off Entitlements
- List Time Off Entitlements
Retrieve a paginated list of time off entitlements
- Get Time Off Entitlement
Retrieve entitlements for an individual engagement
Time Off Requests
- Create Time Off Request
Create a new time off request for an engagement
- List Time Off Requests
Retrieve a paginated list of time off requests
- Get Time Off Request
Retrieve an individual time off request by ID
Expenses
- Create Expense
Create a new expense record
- List Expenses
Retrieve all expenses
- Get Expense
Retrieve an individual expense by ID
- Delete Expense
Delete an expense record by ID
Payroll Changes
- Create Payroll Change
Create a payroll change for an engagement
- List Payroll Changes
Retrieve all payroll changes
- Get Payroll Change
Retrieve a single payroll change by ID
- Update Payroll Change
Update an existing payroll change
Bank Accounts
- List Bank Accounts
Retrieve bank accounts for the company
- Get Bank Account
Retrieve bank account details by ID
Time Sheets
- Create Time Sheet
Create a new time sheet for an engagement
- List Time Sheets
Retrieve all time sheets for the company
- Get Time Sheet
Retrieve an individual time sheet by ID
- Delete Time Sheet
Delete a time sheet
Time Sheet Entrys
- Create Time Sheet Entry
Create a new entry in a time sheet
- Update Time Sheet Entry
Update an existing time sheet entry
- Delete Time Sheet Entry
Delete a time sheet entry
Hiring Employments
- Create Hiring Employment
Create a new hiring employment record
- Get Hiring Employment
Retrieve an individual hiring employment by ID
- Update Hiring Employment
Update a draft hiring employment record
- Delete Hiring Employment
Delete a draft hiring employment record
Other (26)
- Get Company
Retrieve company details for the authenticated organization
- List Webhook Dispatches
Retrieve all webhook dispatches for the authenticated Developer application
- List Departments
Retrieve a paginated list of departments
- List Engagement Allowances
Retrieve a paginated list of allowances for a specific engagement
- List Engagement Bonuses
Retrieve a paginated list of bonuses for a specific engagement
- List Engagement Documents
Retrieve a paginated list of documents for a specific engagement
- List Engagement Payslips
Retrieve a paginated list of payslips for a specific engagement
- List Payroll
Retrieve a paginated list of payroll entries
- Get Payroll Item
Retrieve a single payroll entry by ID
- List Payroll Records
Retrieve payroll records for an individual payroll
- Get Default Payroll Changes Source Types
Retrieve default payroll changes rulesets for source types
- Get Default Payroll Changes Ruleset
Retrieve default payroll changes ruleset
- Get Payroll Changes Source Types
Retrieve payroll changes rulesets for source types
- Get Payroll Changes Ruleset
Retrieve payroll changes ruleset
- Get Hiring Employment Tasks
Retrieve hiring process tasks for an employment
- Update Personal Details
Update personal details for an employment
- Cancel Contract Change
Cancel a contract change request
- Approve Time Off Request
Approve a pending time off request
- Reject Time Off Request
Reject a pending time off request
- Approve Expense
Approve a pending expense
- Decline Expense
Decline a pending expense
- Cancel Payroll Change
Cancel a payroll change
- Submit Time Sheet
Submit a time sheet for approval
- Confirm Time Sheet
Confirm a time sheet
- Submit Hiring Employment
Submit a hiring employment for processing
- Invite Team Member
Send invitation to a team member for a hiring employment
Oyster HR AI Agent Use Cases
Connect your AI agent to Oyster HR and help your team scale the HR operations they run by hand today.
Use StackOne to connect your AI agent to your HRIS, identity management, and LMS to automate employee onboarding.
ViewUse StackOne to connect your AI agent to your HRIS, knowledge base, and messaging tools to automate HR policy Q&A.
ViewUse StackOne to connect your AI agent to your ATS and job boards to automate job posting distribution.
ViewSet Up Your Oyster HR MCP Server in Minutes
One endpoint. Any framework. Your agent is talking to Oyster HR 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>"
]
}
}
}Check More HRIS / HCM MCP Servers
139+ actions
128+ actions
127+ actions
123+ actions
120+ actions
117+ actions
111+ actions
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 200+ Connector Builds Taught Us
MCP wraps APIs, it doesn't replace them. After building 200+ connectors that serve both, here's when each approach wins.
14 min read
Oyster HR MCP Server FAQ
Does StackOne have a Oyster HR MCP server?
Oyster HR MCP server vs direct API integration — what's the difference?
How does Oyster HR authentication work for AI agents?
origin_owner_id.Are Oyster HR MCP tools vulnerable to prompt injection?
What is the context bloat of a Oyster HR agent and how do I avoid it?
Can I limit which actions my Oyster HR agent can access?
Can I create custom agent actions for my Oyster HR MCP server?
When should I NOT use a Oyster HR MCP server?
What AI frameworks and AI clients does the StackOne Oyster HR 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.