Letterdrop
Content planning, writing, SEO, newsletters, and social distribution
The visible B2B content + distribution loop is buildable, but a credible replacement needs more than the first screen. Letterdrop earns its keep through deliverability, reputation, network, so expect a weekend or multi-day build and a narrower personal scope.
Build verification: not recorded. How we judge buildability
What you give up
- large-scale segmentation and automation
- payments, recommendations, and audience network
- sender reputation, deliverability, and suppression handling
- sender reputation and deliverability operations
- bounce, complaint, and suppression handling
Why people still pay
Letterdrop: The editor is trivial compared with inbox placement, compliance, reputation, unsubscribe handling, analytics, and audience growth infrastructure.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first. Optional AI generation needs a provider key, a usage budget and approval to send the selected material.
- Implementation components: Node.js, TypeScript and Express with server-rendered HTML and small browser modules. SQLite through better-sqlite3 with migrations, prepared statements and a single background worker. A single provider SDK with a configured supported model, schema-validated responses and revisioned prompt templates.
- Scope boundary: large-scale segmentation and automation; payments, recommendations, and audience network
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.
Optional external skill: copywriting — Write landing pages and product copy grounded in the intended audience, product value and a clear next action. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: web-design-guidelines — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: sharp-edges — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Project rule — data model: editorial briefs, article revisions, evidence links, derivative channel drafts and CMS publish receipts
Project rule — preserve this invariant: Published copy must be an approved immutable revision; link suggestions cannot fabricate destination pages or auto-publish AI text.
Project rule — acceptance evidence: Delete a proposed internal-link target and flag the suggestion; retry a CMS timeout by reconciling the existing post ID before creating another.
Implementation plan
Phase 1
Scope and fixtures. Implement this bounded workflow: Draft a B2B article from supplied expertise, review factual claims and derive social/email snippets. Suggest internal links only to approved existing URLs, then export or publish through one explicitly configured CMS adapter. Record prerequisites, select representative user-owned fixtures and document the unsupported features: large-scale segmentation and automation; payments, recommendations, and audience network
Phase 2
Durable model. Model editorial briefs, article revisions, evidence links, derivative channel drafts and CMS publish receipts Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: Published copy must be an approved immutable revision; link suggestions cannot fabricate destination pages or auto-publish AI text.
Phase 3
Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them.
Phase 4
Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Treat source documents as untrusted data, prevent them from changing tool permissions, and require review of factual claims before publication. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
Phase 5
Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
Phase 6
Acceptance scenarios. Delete a proposed internal-link target and flag the suggestion; retry a CMS timeout by reconciling the existing post ID before creating another. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.
WORKING SLICE Draft a B2B article from supplied expertise, review factual claims and derive social/email snippets. Suggest internal links only to approved existing URLs, then export or publish through one explicitly configured CMS adapter. Build this scoped Letterdrop-inspired workflow with a documented data model and visible failure states. Architecture - Node.js, TypeScript and Express with server-rendered HTML and small browser modules. - SQLite through better-sqlite3 with migrations, prepared statements and a single background worker. - A single provider SDK with a configured supported model, schema-validated responses and revisioned prompt templates. Prerequisites and limits A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first. Optional AI generation needs a provider key, a usage budget and approval to send the selected material. Outside this release: large-scale segmentation and automation; payments, recommendations, and audience network Data model and correctness editorial briefs, article revisions, evidence links, derivative channel drafts and CMS publish receipts Invariant: Published copy must be an approved immutable revision; link suggestions cannot fabricate destination pages or auto-publish AI text. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. Security and privacy Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Treat source documents as untrusted data, prevent them from changing tool permissions, and require review of factual claims before publication. Recovery and export Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Implementation order 1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Draft a B2B article from supplied expertise, review factual claims and derive social/email snippets. Suggest internal links only to approved existing URLs, then export or publish through one explicitly configured CMS adapter. Record prerequisites, select representative user-owned fixtures and document the unsupported features: large-scale segmentation and automation; payments, recommendations, and audience network 2. Phase 2 — Durable model. Model editorial briefs, article revisions, evidence links, derivative channel drafts and CMS publish receipts Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: Published copy must be an approved immutable revision; link suggestions cannot fabricate destination pages or auto-publish AI text. 3. Phase 3 — Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. 4. Phase 4 — Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Treat source documents as untrusted data, prevent them from changing tool permissions, and require review of factual claims before publication. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results. 5. Phase 5 — Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README. 6. Phase 6 — Acceptance scenarios. Delete a proposed internal-link target and flag the suggestion; retry a CMS timeout by reconciling the existing post ID before creating another. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder. Acceptance Delete a proposed internal-link target and flag the suggestion; retry a CMS timeout by reconciling the existing post ID before creating another. Use real source data or clearly labeled fixtures. Explain unsupported input and provider failures; do not fabricate analytics, delivery receipts, accuracy claims or security guarantees. Optional agent guidance Optional external skill: [copywriting](https://github.com/coreyhaines31/marketingskills/blob/main/skills/copywriting/SKILL.md) — Write landing pages and product copy grounded in the intended audience, product value and a clear next action. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Optional external skill: [web-design-guidelines](https://github.com/vercel-labs/agent-skills/blob/main/skills/web-design-guidelines/SKILL.md) — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Optional external skill: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Project rule — data model: editorial briefs, article revisions, evidence links, derivative channel drafts and CMS publish receipts Project rule — preserve this invariant: Published copy must be an approved immutable revision; link suggestions cannot fabricate destination pages or auto-publish AI text. Project rule — acceptance evidence: Delete a proposed internal-link target and flag the suggestion; retry a CMS timeout by reconciling the existing post ID before creating another.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
prompt copied. want to know what dies next week?
new verdicts + top votes, weekly. free. one-click out.
Letterdrop pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| competitor signal | — | — | Daily competitor/job-change signals to CRM, Salesforce/HubSpot/Outreach/Apollo/Clay sync, email and phone contact data, onboarding about 10 days to live.Custom annual usage-based pricing; 30-day pilot. |
free tierno free tier.
billingannual custom contract; 30-day pilot; usage-based
hidden costsPricing scales with tracked competitor sales headcount; security/enterprise terms are custom.
pricing sources checked 2026-08-10 · pricing source ↗
Questions about Letterdrop
Can you build your own Letterdrop with AI?
Partly. The visible B2B content + distribution loop is buildable, but a credible replacement needs more than the first screen. Letterdrop earns its keep through deliverability, reputation, network, so expect a weekend or multi-day build and a narrower personal scope.
What does the Letterdrop build prompt cover?
The prompt starts with this scope: Draft a B2B article from supplied expertise, review factual claims and derive social/email snippets. Suggest internal links only to approved existing URLs, then export or publish through one explicitly configured CMS adapter. Full-product capabilities excluded from the comparison include: large-scale segmentation and automation; payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling. 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 Letterdrop 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 Letterdrop 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 Letterdrop?
large-scale segmentation and automation; payments, recommendations, and audience network; sender reputation, deliverability, and suppression handling; sender reputation and deliverability operations; bounce, complaint, and suppression handling. Letterdrop: The editor is trivial compared with inbox placement, compliance, reputation, unsubscribe handling, analytics, and audience growth infrastructure.
What can I use instead of building Letterdrop?
The prior-art section lists listmonk, Mautic as starting points. Review their current scope, license and maintenance before adopting one.