Operations · Tonight build

Build your own Harvest

Start timer. Stop timer. Remember what it was for. Harvest charges $13–$17.5 per person per month — that’s $156–$210 a year per person — for something you can replace with focused software of your own. Here is the honest scope, the honest timeline, and the exact prompt to hand your coding agent.

from 4 hoursVery buildable

Who this replacement is for

This build targets a small agency tracking billable time across clients and projects. The goal: capture time with low friction and turn it into clear weekly totals. If you need more than that, keep paying — the point of building it yourself is owning a tool shaped exactly like your workflow, not re-implementing a venture-funded roadmap.

How long it actually takes

One number would be a lie, so here are three. Each tier is a real, usable product — pick the one that matches how much of Harvest you actually use.

EstimateWhat you get
4 hoursrunning timer, weekly timesheet, csv export
12 hoursclients, billable rates, budgets, approvals
1 month+invoicing, online payments, integrations, native apps — the part you should probably skip

What a minimal Harvest alternative needs

Data model

Client, Project, Task, TimeEntry, TimesheetApproval

Integrations

calendar event import as optional suggestions

Capability context

Astro, HTMX, D1

The guardrail

Store all timestamps in UTC, prevent overlapping running timers, and log approval changes.

Deliberate non-goals

Do not build payroll, invoicing, expenses, desktop tracking, or employee surveillance.

The complete build prompt

Copy this into your coding agent of choice. It is scoped for a useful v1 — journeys, screens, business rules, data model, security, tests, and acceptance scenarios included. Pick your stack:

You are building a production-ready software product named “Hourglass”, a deliberately focused alternative to Harvest. Build a complete, usable vertical slice—not a landing page, static mockup, or disconnected collection of components.

WORKING AGREEMENT
Before writing implementation code, produce a short technical plan that names the routes or pages, server actions or endpoints, data tables, important state transitions, authorization boundaries, background jobs, and external adapters. Resolve contradictions in favor of the narrow audience and non-goals below. Prefer a small, legible architecture over speculative abstraction, but do not omit persistence, validation, error handling, or tests.

PRODUCT BRIEF
Primary user: a small agency tracking billable time across clients and projects.
Primary outcome: capture time with low friction and turn it into clear weekly totals.
Product principle: optimize the exact workflow below instead of copying the full breadth of Harvest. A first-time user should understand what to do from the interface itself, without a tour or documentation.

END-TO-END USER JOURNEYS
Implement all of these flows through the real interface and persistent data layer:
1. A team member selects a client, project, and task, starts a timer, adds a note, stops it, and sees the exact entry in the current weekly timesheet.
2. The team member fills missing time manually in the weekly grid, resolves overlap and required-field errors, reviews billable totals, and submits the week.
3. A manager reviews a submitted week, returns it with a comment or approves it, then checks project budget progress and exports approved entries.

SCREENS AND INFORMATION ARCHITECTURE
Build these as coherent responsive views. Each screen must specify its primary action, secondary actions, visible status, validation feedback, empty state, loading or pending state, success confirmation, and recoverable failure state.
1. Timer dashboard: running duration, client, project, task, note, start and stop controls, today’s entries, recent selections, and daily billable total.
2. Weekly timesheet: day and project grid, manual-entry editor, daily and weekly totals, overlap warnings, billable indicators, submission state, and submit action.
3. Clients and projects: active state, task list, member access, billable rates, budget in hours or money, consumed amount, and remaining-budget warning.
4. Approvals and reports: submitted weeks by person, entry detail, return comment, approve action, filters, billable amount, budget progress, and CSV export.

CORE CAPABILITIES
1. running timer with project, task, and note
2. manual entry and weekly timesheet grid
3. clients, projects, billable rates, and project budgets
4. team approval for submitted weeks
5. billable amount, budget progress, and CSV export

DETAILED BEHAVIOR AND BUSINESS RULES
Treat these as server-enforced product requirements, not interface suggestions:
1. Allow at most one running timer per person; starting another timer must atomically stop the current one or require an explicit switch.
2. Store instants in UTC and the user’s timezone, reject overlapping entries, split displayed totals at local day boundaries, and preserve the exact recorded duration.
3. Snapshot the applicable billable rate on each entry so later client or project rate changes do not rewrite historical billable amounts.
4. Submitted weeks are read-only; returning unlocks them with a manager comment, while approval creates an immutable event and only admins may reopen an approved week.

DATA MODEL AND LIFECYCLE
Design a small relational schema centered on Client, Project, Task, TimeEntry, TimesheetApproval. Before implementing it, document:
1. Each table’s purpose, primary key, ownership or tenant boundary, timestamps, status fields, and important attributes.
2. Foreign keys, uniqueness constraints, check constraints, indexes needed by the named screens, and transaction boundaries for multi-record changes.
3. The allowed lifecycle or state transitions, who may trigger each transition, which transitions are terminal or reversible, and what audit history must remain immutable.
4. Archive, retention, and deletion behavior, including what happens to dependent records and external files.
5. Idempotency strategy for submissions, jobs, imports, notifications, webhooks, or retries where applicable.
Use migrations rather than ad-hoc schema creation. Store time instants consistently and retain named timezone context whenever local schedules or dates matter. Never rely on a counter, disabled button, or client-side check to preserve a business invariant.

USERS, AUTHENTICATION, AND PERMISSIONS
Implement only the roles required by the stated audience. Make the ownership and visibility model explicit before coding. Enforce authorization in every server-side query and mutation, including search, exports, attachments, live updates, and guessed URLs—not merely by hiding controls. Use secure session defaults, protect state-changing requests, and provide an understandable signed-out, expired-session, and forbidden state. Seed distinct users when multiple roles are required so permissions can be demonstrated and tested.

INTERACTION AND VISUAL DIRECTION
The product should feel fast, calm, focused, and credible rather than like a generic admin template. Use a clear visual hierarchy, restrained color, readable typography, generous hit targets, and consistent placement for primary actions. Start with server-rendered HTML and progressively enhance only the interactions that benefit from it. The core workflow must remain understandable if enhancement fails.

Start with server-rendered Astro pages and ordinary HTML forms. Use HTMX for form submissions, partial navigation, and server-driven updates, then Alpine.js only for small local browser state. The core workflow must remain understandable if either enhancement layer fails.

Design mobile layouts intentionally instead of simply stacking desktop panels. Support keyboard navigation, visible focus, semantic landmarks, explicit labels, useful page titles, reduced-motion preferences, and screen-reader announcements for asynchronous results. Never use color alone to communicate state. Destructive actions require clear scope and confirmation; safe repeated actions should be idempotent.

TECHNICAL DIRECTION
Build this version with the AHA stack: Astro for routing, layouts, and server-rendered pages; HTMX for interactions that benefit from HTML fragment responses; and Alpine.js for small, local interface state. Prefer Cloudflare D1 for relational persistence, R2 for object storage, Workers for server endpoints and scheduled work, Durable Objects only for coordinated real-time state, and Workflows or Queues for durable background jobs—but only when the product requirements call for them.

Keep domain rules in testable server-side modules instead of route handlers or UI components. Separate persistence, external providers, and background work behind small interfaces without building a framework. Prefer ordinary HTML forms and URLs for durable navigation; use optimistic interaction only when failure can be reconciled clearly.

The product brief currently identifies Astro, HTMX, D1 as capability context. Preserve any required native, browser-only, edge, storage, real-time, or background-processing capability through a narrow adapter appropriate to the selected framework. If the core workflow genuinely requires native or browser APIs, keep that runtime as the primary execution surface rather than simulating inaccessible capabilities or inventing an unnecessary web surface.

Integrate with calendar event import as optional suggestions. For every integration:
- List required environment variables in an .env.example without real secrets.
- Add a small adapter with timeouts, normalized errors, and a deterministic local fake or development path.
- Verify inbound signatures and deduplicate provider events where supported.
- Keep credentials server-side, encrypt long-lived provider tokens at rest, and redact secrets and sensitive payloads from logs.
- Define retry, backoff, and idempotency behavior for any side effect that can be repeated.

SECURITY AND PRIVACY
Store all timestamps in UTC, prevent overlapping running timers, and log approval changes.
Validate, normalize, and length-limit all untrusted input on the server. Escape rendered content by default, sanitize any intentionally accepted markup, rate-limit public or abuse-prone actions, and use private object storage plus short-lived authorized URLs for sensitive files. Collect the minimum personal data necessary for the named workflow. Document retention and deletion behavior. Add specific protections for the riskier surfaces in this app, such as uploads, redirects, outbound requests, email delivery, OAuth, webhooks, CSV import or export, and real-time connections.

ACCEPTANCE SCENARIOS
Automate these app-specific scenarios at the most appropriate level:
1. Given an existing running timer, starting another through two concurrent requests results in one running timer and no overlapping entries.
2. Given a timer crossing local midnight, stopping it preserves one duration while the weekly view allocates time to the correct local dates.
3. Given a submitted week, editing is blocked until a manager returns it; after approval its entries and snapshotted rates remain unchanged in exports.

TESTING
Add focused unit tests for state transitions, authorization predicates, normalization, date or money calculations, and other risky domain rules. Add integration tests for persistence constraints and each external adapter’s success, timeout, retry, and rejection paths. Add at least one browser-level test for every end-to-end journey above, including one small-screen viewport. Tests must use isolated data and run through a documented single command.

OPERATIONS AND FAILURE RECOVERY
Add structured server logs with request, job, or event correlation IDs but no secrets or unnecessarily sensitive data. Make failures actionable in both the interface and logs. Background work must expose pending, succeeded, failed, and retrying states where relevant; do not silently swallow errors. Include safe database migration and rollback guidance, seed data, backup and restore notes, external-data cleanup behavior, and a basic health or diagnostic path appropriate to the stack.

DELIVERABLES
Ship the working application, migrations, representative seed data, tests, .env.example, and a concise README. The README must cover prerequisites, local setup, environment variables, migrations, seed and test commands, deployment, integration setup, backup and restore, security decisions, and known limitations. Seed data should exercise the happy path plus at least one empty, failed, overdue, expired, archived, or permission-restricted state relevant to the product.

DEFINITION OF DONE
The app is complete when a fresh developer can follow the README, create and migrate the database, run the app, sign in as each relevant role, complete every named journey using real persisted data, refresh without losing state, recover from common failures, and use the core interface on phone and desktop. All acceptance scenarios pass, permission boundaries are covered by tests, and no core screen is left as a placeholder.

NON-GOALS
Do not build payroll, invoicing, expenses, desktop tracking, or employee surveillance.

Frequently asked questions

How long does it take to build your own Harvest?

A basic version — running timer, weekly timesheet, csv export — takes about 4 hours. Roughly 12 hours gets you a solid v1 with clients, billable rates, budgets, approvals. Matching everything Harvest really does (invoicing, online payments, integrations, native apps) is closer to 1 month+, which is exactly why you should scope down instead.

How much does Harvest cost if I keep subscribing?

Harvest runs $13–$17.5 per person per month on public paid plans, which is $156–$210 per year for every person on your team. A focused self-built replacement costs your build time plus close-to-zero hosting.

What stack should I use to build a Harvest alternative?

The build prompt on this page ships in four flavors: the AHA stack (Astro, HTMX, Alpine.js), Next.js, Laravel, and Ruby on Rails. The capability context for this product is Astro, HTMX, D1. Pick the stack you already know — the scope matters more than the framework.

What features does a minimal Harvest replacement need?

A useful v1 needs: running timer with project, task, and note; manual entry and weekly timesheet grid; clients, projects, billable rates, and project budgets; team approval for submitted weeks; billable amount, budget progress, and CSV export. Everything else is scope creep until you personally miss it.

What should I deliberately not build?

Do not build payroll, invoicing, expenses, desktop tracking, or employee surveillance.

Prompt copied. Go ship it.