Custom API development services

    Custom API development services for teams that need their tools to talk

    I design, build, and connect APIs — REST endpoints, webhooks, and two-way syncs — so your CRM, data vendors, spreadsheets, and internal tools stop needing a human in the middle.

    Scope

    What custom API development covers

    Most of what I ship falls into six buckets — from brand-new endpoints to bridging a system that was never meant to be automated.

    New APIs for your own product or process

    REST/JSON endpoints with authentication, rate limits, documentation, and versioning — written in Python or Node and hosted on Render or your own cloud.

    Integrations between the tools you already pay for

    CRM ↔ data vendor ↔ email ↔ calendar ↔ Sheets. HubSpot, Google Workspace, Calendly, Stripe, Twilio, and anything else with an API.

    Webhooks and event-driven automation

    Fire on a form submit, a payment, or a task change — with retries, idempotency, and dead-letter logging so nothing silently disappears.

    Data pipelines and scheduled jobs

    Pull, dedupe, enrich, score, and deliver on a schedule, keeping a ledger so the same record is never sent twice.

    AI endpoints

    Wrap OpenAI or Anthropic behind your own API so your apps and spreadsheets call one clean endpoint with your prompts, guardrails, and logging.

    Legacy and no-API systems

    CSV drops, email parsing, and browser automation as a last resort — bridged into a real API the rest of your stack can call.

    Process

    How an engagement works

    1. 01

      Audit call

      Free, 30 minutes. We map the systems, the data moving between them, and the manual step you want gone.

    2. 02

      Scope

      A one-page spec: endpoints, payloads, failure handling, a fixed price, and a date.

    3. 03

      Build

      Working endpoints in days, not months. You get staging access and logs from day one.

    4. 04

      Run

      Deployed to your cloud or mine, with monitoring and a handoff doc so anyone can maintain it.

    Case study

    A recent build

    Monthly data-order engine

    Employee augmentation · API-driven pipeline

    Reads open orders from CRM tasks via API, pulls records from two data-vendor APIs with a scoring cascade, dedupes against a 1M+ contact ledger, enriches phones through a third API, emails each client their file through the Gmail API, and closes the CRM task. It runs unattended every month.

    PythonHubSpot APIGmail APIRender

    Why me

    Why a solo builder instead of an agency

    You talk to the person writing the code

    No account manager relaying requirements. The person on the call is the person shipping the endpoints.

    Fixed scope and price

    A one-page spec with a number on it, so there's no change-order machine turning a small build into a retainer.

    The boring parts are already solved

    I've run these systems in production for two years, so authentication, retries, logging, and rate limits aren't new problems.

    FAQ

    Frequently asked questions

    What does custom API development cost?

    Most integrations are fixed-price from a one-page scope after the audit call; small connectors take days, full pipelines a few weeks. You'll know the number before any code is written.

    Which languages and platforms do you use?

    Python and TypeScript/Node for services, Google Apps Script when the work belongs inside Sheets, hosted on Render, Google Cloud, or your own infrastructure.

    Can you connect a tool that doesn't have an API?

    Usually. CSV exports, email parsing, or browser automation can be wrapped behind a real API so the rest of your stack never knows the difference.

    Who owns the code?

    You do. Everything ships in your repo with a handoff doc; there's no lock-in and no licence fee.

    Do you handle authentication and security?

    Yes — OAuth or API keys, secrets kept out of code, least-privilege scopes, and logging that lets you audit every call.

    What happens after launch?

    Monitoring and a maintenance window are included in the scope; ongoing support is available monthly if you want it.

    Let's Talk

    Ready to work
    smarter?

    Whether you need a workflow automated, an AI assistant built, or two systems finally talking to each other, let's build it.

    Or send a message