Builder & AI Agent API Playbook
Tutorials, comparisons, and use cases for grounding LLM answers, building agent workflows, and shipping production AI features.
How to Build an Investment Research Agent: Markets, Fundamentals, SEC & Economic Data in One API
An investment-research agent needs five different data layers — prices, fundamentals, filings, macro, and news — each normally a separate vendor, key, and schema. Here's how to wire all five behind one endpoint set, with working code and the cost math.
Build a CVE & Vulnerability-Intelligence Agent: CISA KEV, NVD, EPSS & MITRE ATT&CK in One API
Every security team drowns in CVEs. The signal isn't severity — it's whether a vuln is being exploited and how likely it is to be. Here's how to build an agent that fuses NVD, CISA KEV, EPSS, and ATT&CK to answer 'what do I patch first?'
Real-Time Market Data API for AI Agents: Stocks, Crypto, Forex & ETFs in One Endpoint
Most market-data APIs were built for dashboards and quant pipelines, not LLM agents. Here's what changes when your consumer is a model — natural-language queries, one shape across asset classes, only-on-success billing — and how API Pick Markets compares to the incumbents.
Company Fundamentals API: Balance Sheet, Cash Flow & Insider Trades for Finance Agents
Prices tell you what the market thinks; fundamentals tell you whether it's right. Here's a fundamentals API shaped for AI agents — statements, dividends, and insider trades in one endpoint — and how it compares to raw SEC EDGAR and the statement-API vendors.
Economic Data API for AI Agents: FRED, BLS, World Bank & IMF in One Call
FRED's API is excellent — and US-centric, series-ID-driven, and one of several macro sources you'll end up needing. Here's an economic-data endpoint that fuses FRED, BLS, World Bank, and IMF behind one natural-language call for macro-aware agents.
Best Web Search APIs for AI Agents in 2026 (Compared)
Bing Search retired in 2025 and a dozen agent-native search APIs rushed to replace it. Here is the practical, up-to-date map of who returns what, who charges how, and which one to wire into your agent.
Exa vs Tavily: Which Search API for Your AI Agent? (2026)
Exa and Tavily are the two names that come up first when you wire search into an agent. They solve the same job in opposite ways. Here is the honest head-to-head, with real API shapes and 2026 pricing.
Agentic Search vs SERP Scraping: Why Agents Need a Different API
For twenty years, a search API meant 'scrape Google's results page.' AI agents broke that assumption. Here is what agentic search actually is, why it emerged, and when the old SERP model still makes sense.
Google Patents API Is Dead — 6 Alternatives for Prior-Art and Freedom-to-Operate Search
Google Patents Public Datasets retired without a documented replacement, and the USPTO migrated PEDS into a new Open Data Portal mid-2026, breaking pipelines on the way. Here's what actually works in 2026 for prior-art, FTO, and IP-research workloads — six alternatives, side by side.
How to Build a Scientific Literature-Review Agent Without Getting Rate-Limited
Build a literature-review agent on raw arXiv + PubMed + Semantic Scholar today and you'll hit 429s before you finish ten papers. Here's why the rate limits got worse, what PaperQA / Undermind actually do under the hood, and a working pattern that survives a real review session.
Polymarket vs Kalshi API: A Developer's Side-by-Side Guide (Auth, CLOB, WebSocket, Historical Data)
Polymarket and Kalshi run the same primitive — yes/no contracts on a CLOB — through completely different APIs. One demands EIP-712 signatures and a Polygon wallet; the other is a REST endpoint with optional FIX. If you're building a forecasting agent, an arbitrage bot, or a smart-money monitor, here's the side-by-side guide that should already exist.
Citation-Grounded UK Case Law Retrieval After Ayinde v Haringey
Ayinde v Haringey changed the calculus for UK legal AI overnight. A barrister cited five fake cases generated by an LLM and got referred to the Bar Standards Board. Hallucinated citations now have professional-conduct consequences. Here's the developer's guide to building citation-grounded UK case law retrieval — TNA Find Case Law, legislation.gov.uk, neutral-citation parsing, and how to wire it into a working agent.
Wiring ClinicalTrials.gov v2 + openFDA + ChEMBL into a License-Clean Drug Intelligence Endpoint
Pharma R&D, medical-AI startups, and pharmacovigilance teams all want the same thing: one endpoint that pulls trials, labels, adverse events, and bioactivity in a license-clean way. Here's the working architecture, with the trap doors that have surprised teams in production.
Build a Research Agent with Search + URL Extract (Claude tool use, end-to-end)
Most 'AI research agent' tutorials stop at 'here's a tool definition.' This one ships a working agent: question in, cited answer out. Search, extract, reason, cite — all under 120 lines of Python.
Building a Due-Diligence Agent on SEC Filings (10-K, 10-Q, 8-K, Earnings)
Reading a 10-K is mostly Ctrl+F. Doing it for fifty companies is a job. Replace the boring 80% with a search-and-extract agent against SEC EDGAR — keep the 20% that matters for the human analyst.
Why APIs Should Charge Only on Success — The Case for HTTP-200 Billing
Most APIs charge on every billable call. AI agents retry on flaky upstream services constantly — which means the legacy 'always charge' model effectively taxes resilience. Here's the case for billing only on HTTP 200, and what it changes about how you design agents.
Tavily vs Exa vs Serper vs API Pick: Which Web Search API for LLMs?
Tavily, Exa, Serper, and API Pick all promise to be the search layer for your LLM. They differ sharply on output shape, filters, and how they bill. Here is a side-by-side from someone who ships agents.
Firecrawl vs Jina Reader vs API Pick: URL Content Extraction APIs Compared
If you have ever shipped an agent that reads a list of URLs and summarises them, you have hit the URL-cleanup tax. Firecrawl, Jina Reader, and API Pick Extract solve it differently — here is the practical comparison.
How to Add Real-Time Web Search to an OpenAI or Claude Agent in 4 Steps
Want your agent to ground answers in current information? You need exactly two things: a search API that returns LLM-ready snippets, and a tool definition the model can call. This walkthrough does both in 4 steps.
Building a Morning Briefing Agent with the News Search API
Every founder, PM, and analyst wants the same thing at 8am: a clean digest of what changed overnight. With a News Search API, an LLM, and an HTTP-cron platform, you can ship one in an afternoon.