Bigin
Run a small-business pipeline with contacts, activities, and simple workflows
The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Bigin, run a small-business pipeline with contacts, activities, and simple workflows. The hard boundary is zoho ecosystem, telephony, forms, integrations, and mobile apps, plus integrations, data quality, and workflow lock-in.
Build verification: not recorded. How we judge buildability
What you give up
- Zoho ecosystem, telephony, forms, integrations, and mobile apps
- automatic email and calendar capture
- data enrichment
- large integration ecosystem
- enterprise reporting
Why people still pay
People still pay for Bigin because CRM value compounds as the system becomes the shared memory of every customer interaction and embeds itself in the rest of the stack. The recurring cost buys deduplication, permissions, imports, sync, enrichment, email capture, automations, backups, and audit history, not just the visible interface.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- Runtime and tools: TypeScript, React, Node and PostgreSQL with workspace membership enforced on the server.
- Before starting: A PostgreSQL database, session authentication, two isolated example workspaces and private attachment storage.
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Project rule — domain: Store Contact, Company, Deal, StageTransition and Activity; every open deal has a responsible owner and closed deals keep their historical value/currency rather than inheriting later rate edits.
Project rule — scope and recovery: Keep imports reversible through import batches and exact-match duplicate suggestions. No automatic enrichment or inferred contact identity; outreach and accounting remain separate.
Project rule — acceptance: Move a deal from proposal to won, reopen it and complete its follow-up; the history records all transitions and overdue counts exclude the completed activity.
Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated.
Recommended skill: supabase-postgres-best-practices — review this PostgreSQL domain schema, uniqueness constraints, transaction boundaries and access-scoped queries; Supabase hosting is not required. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Recommended skill: web-design-guidelines — review keyboard access, focus, validation, error recovery and the readable work/review interface or HTML report. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Implementation plan
Phase 1
Pin the working slice and create its example input: Capture small-business leads, move opportunities through a short pipeline and make the next scheduled follow-up obvious. Confirm setup: A PostgreSQL database, session authentication, two isolated example workspaces and private attachment storage.
Phase 2
Implement persistence and write-time invariants before decorating the UI: Store Contact, Company, Deal, StageTransition and Activity; every open deal has a responsible owner and closed deals keep their historical value/currency rather than inheriting later rate edits.
Phase 3
Connect the working view to real saved state. Check membership on reads, mutations, attachments and exports. Keep activity history separate from editable current state; do not make private records public through search.
Phase 4
Expose the app-specific limits and recovery path in context: Keep imports reversible through import batches and exact-match duplicate suggestions. No automatic enrichment or inferred contact identity; outreach and accounting remain separate.
Phase 5
Walk through this concrete acceptance case and preserve its exported evidence: Move a deal from proposal to won, reopen it and complete its follow-up; the history records all transitions and overdue counts exclude the completed activity. Finish the README and backup/restore instructions; report unfinished capabilities explicitly.
Build the following focused alternative to Bigin. This is a deliberately limited personal or small-team substitute, not parity with the paid service. WORKING SLICE Capture small-business leads, move opportunities through a short pipeline and make the next scheduled follow-up obvious. SETUP AND ARCHITECTURE Use TypeScript, React, Node and PostgreSQL with workspace membership enforced on the server. Prerequisites: A PostgreSQL database, session authentication, two isolated example workspaces and private attachment storage. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store Contact, Company, Deal, StageTransition and Activity; every open deal has a responsible owner and closed deals keep their historical value/currency rather than inheriting later rate edits. IMPLEMENTATION CONTRACT Check membership on reads, mutations, attachments and exports. Keep activity history separate from editable current state; do not make private records public through search. Provide an input/setup view, the main work view, and a review/export view appropriate to this workflow. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Keep imports reversible through import batches and exact-match duplicate suggestions. No automatic enrichment or inferred contact identity; outreach and accounting remain separate. ACCEPTANCE SCENARIO Move a deal from proposal to won, reopen it and complete its follow-up; the history records all transitions and overdue counts exclude the completed activity. Also reopen the app after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a runnable repository with migrations or project-format versioning, a non-sensitive example, environment/permission setup, the exact manual acceptance steps, and a backup/export-and-restore walkthrough. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
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Alternatives to building your own
all 8 free alternatives to Bigin →· no votes, no pay-to-list · just what's real
Bigin pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| free | $0/user | $0/user | 1 user and 500 total records |
| express | $9/user | $7/user | 50,000 records; no user-count limit (each user requires a license) |
| premier | $15/user | $12/user | 100,000 records; no user-count limit (each user requires a license) |
| bigin 360 | $21/user | $18/user | 1,000,000 records; no user-count limit (each user requires a license) |
free tier1 user and 500 records total (contacts, companies, pipelines, activities, products and notes all count as records)
billingmonthly + annual
hidden costsLocal taxes may be added despite contradictory wording on the page; paid plans charge for every user. Add-ons are sold separately in the Bigin Store. Annual downgrades can create account credits rather than cash refunds.
pricing sources checked 2026-08-12 · pricing source ↗
Questions about Bigin
Can you build your own Bigin with AI?
Partly. The core loop is buildable, but a dependable replacement becomes a real weekend or multi-day project. For Bigin, run a small-business pipeline with contacts, activities, and simple workflows. The hard boundary is zoho ecosystem, telephony, forms, integrations, and mobile apps, plus integrations, data quality, and workflow lock-in.
What does the Bigin build prompt cover?
The prompt starts with this scope: Capture small-business leads, move opportunities through a short pipeline and make the next scheduled follow-up obvious. Full-product capabilities excluded from the comparison include: Zoho ecosystem, telephony, forms, integrations, and mobile apps; automatic email and calendar capture; data enrichment. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Bigin prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Bigin project take?
The catalogue estimate is multi-day for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Bigin?
Zoho ecosystem, telephony, forms, integrations, and mobile apps; automatic email and calendar capture; data enrichment; large integration ecosystem; enterprise reporting. People still pay for Bigin because CRM value compounds as the system becomes the shared memory of every customer interaction and embeds itself in the rest of the stack. The recurring cost buys deduplication, permissions, imports, sync, enrichment, email capture, automations, backups, and audit history, not just the visible interface.
What price is this guide comparing against?
The recorded Express plan is $9/mo per seat (monthly per user), checked 2026-07-31. Check the linked pricing source before buying. Building your own also has hosting, API and maintenance costs; the recorded amount is not a guaranteed saving.
What can I use instead of building Bigin?
Twenty: A modern pipeline CRM with custom objects, views and mailbox sync; the subscription becomes a Compose file. Krayin CRM: A Laravel sales pipeline with leads, contacts and email; glossy enough, but it still wants a PHP stack. EspoCRM: A traditional CRM that actually lets you change the data model; polished enough, but still your server. Compare all listed options at https://howtovibecodeit.dev/bigin/alternatives. Check each option's license, hosting needs and feature limits.