feat(tools): Add Greenhouse Integration for Recruiting Automation

[Samir-atra]

Overview

This PR implements comprehensive integration with the Greenhouse Harvest API, enabling agents to automate recruiting workflows. It adds 6 new MCP tools that consistently allow agents to list jobs, retrieve detailed job info, manage candidates, and track applications.

Branch: feat/greenhouse-integration
Fixes: #3062
Parent Issue: #2805

Key Features

1. Greenhouse Client (aden_tools.tools.greenhouse_tool):

   • Full implementation of a robust GreenhouseClient handling HTTP Basic Auth.
   • Smart Pagination: Automatically handles link-based pagination logic to fetch complete datasets (e.g., all jobs or candidates) while respecting rate limits.
   • Error Handling: Specific handling for 401 (Auth), 403 (Permission/HTTPS), 404 (Not Found), and 429 (Rate Limit) errors.

2. New MCP Tools:

   • greenhouse_list_jobs: List job postings with status/department filters.
   • greenhouse_get_job: Get detailed metadata for a specific job.
   • greenhouse_list_candidates: Search/filter candidates by activity or dates.
   • greenhouse_get_candidate: Retrieve full profile including resume info/notes.
   • greenhouse_add_candidate: Submit sourced candidates directly to a job pipeline.
   • greenhouse_list_applications: Track candidate progress per job.

3. Credential Management:

   • Added GREENHOUSE_API_KEY to the credential registry (tools/src/aden_tools/credentials/greenhouse.py).

Use Cases Enabled (from #2853)

• Job Board Sniper: Can now use greenhouse_list_jobs(status="open") to monitor hiring trends or competitor roles.
• Recruiting Agent: Can source candidates from LinkedIn/GitHub and immediately submit them via greenhouse_add_candidate.
• RevOps/Hiring Manager: Can track pipeline health via greenhouse_list_applications.

Testing

• 100% Unit Test Coverage: Added tools/tests/tools/test_greenhouse_tool.py covering:
  • Authentication formatting.
  • Pagination logic (ensuring multiple pages are stitched correctly).
  • Payload structure for candidate creation.
  • All error scenarios (401, 403, 404, 429, timeouts, network errors).
  • Positional argument assertions for httpx calls.

Breaking Changes

• None. This is a net-new addition.

Checklist

• Implemented core client and 6 tools
• Added credential spec
• Registered tools in aden_tools.tools
• Added comprehensive unit tests
• Verified clean linting and passing tests

[github-actions]

PR Closed - Requirements Not Met

This PR has been automatically closed because it doesn't meet the requirements.

PR Author: @Samir-atra
Found issues: #3062 (assignees: none), #2805 (assignees: none), #2853 (assignees: none)
Problem: The PR author must be assigned to the linked issue.

To fix:

1. Assign yourself (@Samir-atra) to one of the linked issues
2. Re-open this PR

Exception: To bypass this requirement, you can:

• Add the micro-fix label or include micro-fix in your PR title for trivial fixes
• Add the documentation label or include doc/docs in your PR title for documentation changes

Micro-fix requirements (must meet ALL):

Qualifies	Disqualifies
< 20 lines changed	Any functional bug fix
Typos & Documentation & Linting	Refactoring for "clean code"
No logic/API/DB changes	New features (even tiny ones)

Why is this required? See #472 for details.

[Samir-atra]

hello @austin931114 @Hundao @bryanadenhq @RichardTang-Aden

Please check this out, I need to get assigned to move forward.

I look forward to hearing from you.

Kind regards
Samer