Sinatra.dev VS DynamicDocumentAPI

Sinatra.dev's answer

Small engineering teams and solo founders with a backlog of well specified tickets they never get to: reproducible bugs, small features with acceptance criteria, the work that is clear enough to hand off but keeps getting pushed behind bigger things. Teams already working out of Linear, GitHub Issues or Slack who don't want another tool to learn, and who would rather run agent work on the Claude or ChatGPT subscription they already have than open a new metered account somewhere else.

DynamicDocumentAPI's answer:

Developers and product teams whose software has to send documents: invoices after a payment, certificates after a course, reports, labels and statements. Typical users are SaaS companies, marketplaces, e-commerce and learning platforms. A second group are businesses in Germany and the EU that need compliant e-invoices (XRechnung, ZUGFeRD) for the German B2B e-invoicing mandate and public-sector buyers. No-code builders use it through Zapier, Make and n8n, and teams building AI agents use the MCP server.

Sinatra.dev's answer

I built a pet sitting marketplace with my wife. She always had features she wanted shipped and every one of them went through me, so I spent about three months building an agent she could assign tickets to instead. She writes the ticket, assigns it, and a PR comes back. She's now a big contributor to that codebase without me being in the way. I started handing it my own backlog too and eventually it turned into a product. It has been a lot harder to build than I expected, lots of edge cases, which is why it started with just Linear and GitHub issues (Slack, a CLI and an MCP server came later) and why the agent doesn't merge its own PRs, you still do that last part yourself.

DynamicDocumentAPI's answer:

Almost every product eventually needs to produce documents, and most teams end up building their own rendering stack: a headless browser, fonts, page breaks, storage and retries. It works until an invoice splits a table row or a certificate shows the wrong date, and then it becomes a support ticket. We built Dynamic Document API to be that layer for them: templates, rendering and delivery as one service, hosted in Europe, treating pagination, fonts and formatting as engineering problems rather than edge cases. When e-invoicing became mandatory for B2B in Germany, we added validated XRechnung and ZUGFeRD output, and with AI agents producing more paperwork, an MCP server followed.

Sinatra.dev's answer

TypeScript throughout. A Fastify API for webhooks and OAuth, a Temporal worker that orchestrates each agent run, Next.js for the dashboard and the site, and Prisma on Postgres. Every task gets its own Daytona sandbox with the repository cloned in; the sandbox stops when the task goes quiet and is reused for follow-ups. Model access is bring your own: an Anthropic or OpenRouter API key, or a Claude or ChatGPT subscription connected to the workspace.

DynamicDocumentAPI's answer:

Rendering runs in Rust workers that drive headless Chromium over the DevTools protocol, with MiniJinja for templates. The API and control plane are built with Django and Django REST Framework, with Celery, PostgreSQL, Valkey and NATS JetStream for queues and events, and S3-compatible object storage for files. PDF/A output is checked with veraPDF and e-invoices with the official KoSIT validator. The dashboard and website are built with Next.js. Everything runs on Kubernetes in data centres in Germany.

Sinatra.dev's answer

It runs on the model subscription you already pay for. You assign a Linear issue, label a GitHub issue or mention it in Slack, the agent does the work in its own isolated sandbox and comes back with a pull request, and the model bill goes to your own Claude or ChatGPT subscription or API key. Sinatra never bills for model usage. The free plan is 1 agent at a time, plus 1 waiting, with no daily limit and no card. Pricing was the reason we built it in the first place, the agents we tried billed in credits you couldn't predict.

DynamicDocumentAPI's answer:

It covers the whole path from data to finished document in one API: you design a template in a visual or HTML editor (or send raw HTML, CSS or Markdown), send JSON, and get a PDF or image back. The same service also creates e-invoices (XRechnung, EN 16931, Factur-X / ZUGFeRD) that are validated against the official rules before they are returned, and can embed them in the PDF. Rendering is deterministic: the same template and data always give the same document, laid out by a headless browser, with no AI model generating content. Everything runs in the EU (Germany). It also ships an MCP server, so AI agents like Claude and ChatGPT can render documents directly.

Sinatra.dev's answer

Pricing and entry points. Plans are one flat monthly price for the whole workspace, any number of people: Pro is $20/mo for 3 agents at a time, plus 10 waiting, agents work until they're done, and inference runs on your own Claude or ChatGPT subscription or API key, so Sinatra never bills for model usage. And it works from Linear issues, GitHub issues and Slack threads, so a team whose tickets live in Linear can assign work to the agent the way they'd assign a teammate. It also reviews its own diff and posts the findings on the PR, fixes failing CI, and pushes revisions when a reviewer leaves comments. To be honest about the limits, it doesn't work from Jira, and the agent never merges its own PRs, a person does that.

DynamicDocumentAPI's answer:

Most document APIs do one thing: convert HTML to PDF, or fill templates. Dynamic Document API does both, adds image templates, PDF merging and validated e-invoices, and offers them through a REST API, SDKs for Node and Python, Zapier, Make, n8n and an MCP server for AI agents. Data is processed and stored in the EU only, files come back as signed links that expire, and storing nothing at all is a supported option. Pricing is predictable: one published credit table, the same core features on every paid plan and a spend cap you control. We also publish a render-time benchmark with its method and raw data, so you can check our speed instead of trusting a claim. The free plan includes 50 renders a month without a credit card.

DynamicDocumentAPI's answer:

Dynamic Document API is a young product. Our users are mostly developers and small SaaS teams, and we don't name customers without their permission.