Mercury MCP Server
for AI Agents
Connect your AI agent to StackOne's Mercury MCP server and give it 47 MCP tools out of the box. Auth, tool execution, and security all managed.
StackOne 
Coverage
47 Agent Actions
Create, read, update, and delete across Mercury — and extend your agent's capabilities with custom actions.
Authentication
Agent Tool Authentication
Per-user OAuth in one call. Your Mercury MCP server gets session-scoped tokens with zero credentials stored on your infra.
Agent Auth →
Security
Agent Protection
Every Mercury 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 Mercury call.
Tools Discovery →What is the Mercury MCP Server?
A Mercury MCP server lets AI agents read and write Mercury data through the Model Context Protocol — Anthropic's open standard for connecting LLMs to external tools. StackOne's Mercury MCP server ships with 47 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 Mercury MCP Tools
Every action from Mercury's API, ready for your agent. Create, read, update, and delete — scoped to exactly what you need.
Clients
- Create Client
Create a new client (hiring organisation) in Mercury.
- List Clients
Retrieve all clients (hiring organisations) in the Mercury tenant.
Contacts
- Create Contact
Create a new Mercury contact (candidate, client contact, or both).
- List Contacts
Retrieve Mercury contacts (candidate contacts, client contacts, or both), paginated.
Vacancies (batch)s
- Create Vacancies (batch)
Create a batch of vacancies in Mercury.
- Update Vacancies (batch)
Fully update a batch of vacancies in Mercury.
Other (41)
- Create Activity On A Contact
Log a new CRM activity (email, phone call, task, appointment, or update) against a contact.
- Create Annotation On A Contact
Create a note against a Mercury contact.
- Upload Document To A Candidate
Upload a document (max 5MB) against a candidate.
- Upload CV To Create New Candidate (parse)
Upload a CV to create a new candidate via Mercury's CV parsing engine.
- Upload CV To Update Existing Candidate (parse)
Upload a CV to update an existing candidate via Mercury's CV parsing engine.
- Create Compliance Record On A Placement
Create a compliance / vetting record attached to a Mercury placement.
- Upload Evidence To A Compliance Record
Upload an evidence document to a compliance record.
- Upload CV To A Contact
Upload a CV document against a Mercury contact.
- Upload Document To A Contact
Upload a non-CV document against a Mercury contact.
- List Activity Purposes
Retrieve tenant-configured activity purposes (categories).
- List Activities For A Contact
Retrieve all activities logged against a Mercury contact.
- List Contact Annotations
Retrieve all annotations (notes) on a Mercury contact.
- Get Candidate Company By ID
Retrieve a candidate company (candidate's employing company) by Id.
- Get Candidate By ID
Retrieve a candidate (contact with isCandidateContact=true) by Id.
- List Placements For A Candidate
Retrieve all placements a candidate has been involved in.
- Get Client By ID
Retrieve a single Mercury client by Id.
- List Compliance Records For A Placement
Retrieve all compliance records attached to a placement.
- Get Compliance Record By ID
Retrieve a compliance record by Id (includes base64 evidence file if present).
- Get Contact By ID
Retrieve a single Mercury contact by Id.
- Get Primary CV For A Contact
Retrieve the primary CV document for a Mercury contact (base64-encoded content).
- List Contact Files (SharePoint)
List all SharePoint files associated with a Mercury contact.
- Get File Content By Path
Retrieve a document's content (base64) by SharePoint path.
- List Contact Education
Retrieve contact education records across the tenant with pagination.
- List Placements
Retrieve Mercury placements with pagination and filters.
- Get Placement By ID
Retrieve a Mercury placement by Id.
- List Finance Rates For A Placement
Retrieve pay/charge finance rates attached to a placement.
- List All Placement Fees
Retrieve placement fees across all placements on the tenant with pagination.
- List Fees For A Placement
Retrieve all fees attached to a single placement.
- List Contact Skills
Retrieve contact skill records across the tenant with pagination.
- List System Users
Retrieve all Mercury system users (recruitment consultants and staff members).
- Get System User By ID
Retrieve a single Mercury system user by Id.
- List Vacancies
Retrieve Mercury vacancies (open positions) with pagination and filters.
- Get Vacancy By ID
Retrieve a Mercury vacancy by Id.
- List Shortlists For A Vacancy
Retrieve the candidate shortlist for a Mercury vacancy.
- List Contact Work History
Retrieve contact work history records across the tenant with pagination.
- Patch Client
Partially update a Mercury client.
- Patch Compliance Record
Partially update a compliance record.
- Patch Contact
Partially update a Mercury contact.
- Patch Skill Level
Update level, experience, or proficiency on a contact skill record.
- Patch Vacancies (batch)
Partially update a batch of vacancies in Mercury.
- Patch Work History Entry
Update a contact work history entry.
Mercury AI Agent Use Cases
Connect your AI agent to Mercury and help your team scale the finance operations they run by hand today.
Automate invoice processing with AI agents connected to your ERP, accounting software, and AP tools through StackOne.
ViewUse StackOne to connect your AI agent to your accounting, CRM, and messaging systems to automate Accounts Receivable dunning and payment follow-up.
ViewUse StackOne to connect your AI agent to your accounting, email, and document management systems to automate invoice processing and purchase order matching.
ViewSet Up Your Mercury MCP Server in Minutes
One endpoint. Any framework. Your agent is talking to Mercury 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 Accounting 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
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
Mercury MCP Server FAQ
Does StackOne have a Mercury MCP server?
Mercury MCP server vs direct API integration — what's the difference?
How does Mercury authentication work for AI agents?
origin_owner_id.Are Mercury MCP tools vulnerable to prompt injection?
What is the context bloat of a Mercury agent and how do I avoid it?
Can I limit which actions my Mercury agent can access?
Can I create custom agent actions for my Mercury MCP server?
When should I NOT use a Mercury MCP server?
What AI frameworks and AI clients does the StackOne Mercury 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.