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Live 52 Actions
Oyster HR MCP Server
for AI Agents
Connect your AI agent to StackOne's Oyster HR MCP server and give it 52 MCP tools out of the box. Auth, tool execution, and security all managed.
Oyster HR MCP Server
Built by 
StackOne
StackOne 
Coverage
52 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 52 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.
Engagements
- List Engagements
Retrieve a paginated list of engagements (employees and contractors)
- Get Engagement
Retrieve details of a specific engagement by ID
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 (24)
- Get Company
Retrieve company details for the authenticated organization
- 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
- 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.
Employee Onboarding
Use StackOne to connect your AI agent to your HRIS, identity management, and LMS to automate employee onboarding.
View HR Policy Q&A Chatbot
Use StackOne to connect your AI agent to your HRIS, knowledge base, and messaging tools to automate HR policy Q&A.
View Job Posting Distribution
Use 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
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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
Oyster HR MCP Server FAQ
Does StackOne have a Oyster HR MCP server?
Yes. StackOne offers a hosted Oyster HR MCP server with 52 pre-built actions, and every action is tested and QA'd by StackOne. Connect it to Claude, Cursor, and any other MCP client, or to any agent framework through the AI Action SDK. It ships with managed agent authentication, prompt injection defense, and tool discovery with server-side execution that preserve your agent's context window and keep reasoning performance.
Oyster HR MCP server vs direct API integration — what's the difference?
A Oyster HR MCP server and direct API integration serve different use cases. Direct API integration is for software-to-software — backend code calling Oyster HR. A Oyster HR MCP server is for AI agents — MCP clients like Claude and Cursor, plus framework agents built with OpenAI, LangChain, or Vercel AI — discovering and calling Oyster HR at runtime. StackOne provides both.
How does Oyster HR authentication work for AI agents?
Oyster HR authentication for AI agents works through a StackOne Connect Session. Create one via the dashboard or the SDK — you get an auth link and ready-to-paste config for Claude Desktop, Cursor, and other MCP clients. Your user authenticates their own Oyster HR account; StackOne handles token exchange, storage, and refresh. Credentials never reach the LLM, and each user is isolated via
origin_owner_id.Are Oyster HR MCP tools vulnerable to prompt injection?
Yes — Oyster HR MCP tools can be vulnerable to indirect prompt injection. Any tool that reads user-written content — documents, messages, tickets, records, or free-text fields — is a potential vector. StackOne Defender scans every tool response before it enters the agent's context — regex patterns in ~1ms, then a MiniLM classifier in ~4ms. 88.7% accuracy, CPU-only.
What is the context bloat of a Oyster HR agent and how do I avoid it?
Context bloat happens when Oyster HR tool schemas and API responses eat your Oyster HR agent's memory, preventing it from reasoning effectively. A single Oyster HR query can return a massive JSON response, and connecting multiple tools compounds the problem. Tools Discovery and Code Mode reduce context bloat — loading only relevant tools per query and keeping raw responses out of the agent's context.
Can I limit which actions my Oyster HR agent can access?
Yes — you can limit which actions your Oyster HR agent can access directly from the StackOne dashboard. Toggle actions on or off, or restrict them to specific accounts, with no code changes to your agent. Session tokens can be scoped to exact actions so if one leaks, exposure stays contained.
Can I create custom agent actions for my Oyster HR MCP server?
Yes — you can create custom agent actions for your Oyster HR MCP server using Connector Builder. It's an integration agent your coding assistant (Claude Code, Cursor, or Copilot) can invoke to research Oyster HR's API, generate production-ready connector YAML, test against the live API, and validate before you ship.
When should I NOT use a Oyster HR MCP server?
Skip a Oyster HR MCP server if your integration is purely software-to-software — direct Oyster HR API integration is simpler when no AI agent is involved. For deterministic, compliance-critical operations (financial transactions, regulatory reporting), direct API gives you predictable behavior without agent-driven decision-making. MCP shines when AI agents need to dynamically discover and call Oyster HR actions at runtime.
What AI frameworks and AI clients does the StackOne Oyster HR MCP server support?
The StackOne Oyster HR MCP server supports both. MCP clients (paste-and-go apps): Claude Desktop, Claude Code, Cursor, VS Code, Goose. Agent frameworks (code SDKs you build with): OpenAI Agents SDK, Anthropic, Vercel AI, Google ADK, CrewAI, Pydantic AI, LangChain, LangGraph, Azure AI Foundry.
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.