Harvest
Combined time tracking and invoicing REST API for logging time entries, managing projects/clients/tasks, generating invoices from time data, and processing payments.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
OAuth2 and Personal Access Tokens. SOC2 Type II. Time and billing data — sensitive for many businesses. Token-based auth with account-level scope. Webhook HMAC validation.
⚡ Reliability
Best When
You need combined time tracking AND invoicing in a single API, particularly for freelancers or agencies that bill clients based on tracked hours.
Avoid When
You only need time tracking without invoicing — Toggl is simpler and cheaper for that use case.
Use Cases
- • Automating invoice generation by pulling time entries and creating invoices via API
- • Logging time entries from agent task completions into project billing records
- • Retrieving project budget and time-to-completion data for agent reporting
- • Syncing time data to accounting systems (QuickBooks, Xero) via Harvest's data
- • Building custom dashboards over Harvest time and budget data
Not For
- • Simple time tracking without invoicing (Toggl is cheaper and simpler)
- • Enterprise resource planning or complex project management
- • High-volume time entry imports (rate limits apply)
- • Applications requiring real-time time tracking push notifications
Interface
Authentication
Personal Access Token for own account automation. OAuth2 for third-party integrations to access user accounts. Harvest-Account-Id header required alongside auth token for multi-account setups.
Pricing
Simple, flat per-user pricing. Free tier is too limited for real use. Pro at $12/user/month includes everything. Good value for agencies that need time + invoicing in one tool.
Agent Metadata
Known Gotchas
- ⚠ Harvest-Account-Id header required for all requests — easy to forget if building multi-account integration
- ⚠ Rate limit (100 req/15s) is generous for most use cases but can be hit in batch operations
- ⚠ Time entries require both project_id and task_id — must look up both before creating entry
- ⚠ Invoice creation from time entries is a multi-step process: select entries → create invoice → finalize
- ⚠ OAuth tokens expire and require refresh — implement token refresh before building OAuth integrations
- ⚠ No webhooks — agents must poll for new time entries or invoice status changes
- ⚠ Pagination uses page-based approach with per_page limit (up to 100) — must handle multiple pages for large datasets
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for Harvest.
Scores are editorial opinions as of 2026-03-06.