May 2026 Summaries

This guide provides a comprehensive walkthrough on building a custom Gmail API integration using an AI coding agent and Nango, highlighting features such as Gmail authentication UI, email sending capabilities, and durable mailbox syncing. It discusses the complexities of integrating Gmail API, including handling raw MIME messages, managing sync operations, real-time notifications with Google Cloud Pub/Sub, and navigating restricted scopes requiring Google verification. Nango offers a code-first API integration platform, simplifying the process with managed authentication, retries, and observability across multiple APIs. It facilitates integration by providing pre-built templates, enabling developers to use AI agents like Claude or Cursor to generate code, test implementations, and customize actions and syncs. The guide emphasizes using Nango to manage OAuth, leverage pre-configured developer apps for testing, and efficiently handle quota constraints and rate limits, ensuring a streamlined and reliable integration process with Gmail and other APIs.

The migration guide provides a comprehensive roadmap for developers transitioning integrations from Composio to Nango by mapping Composio features to their Nango equivalents and detailing step-by-step migration procedures. It highlights the use of AI coding agents, such as Claude Code and Codex, paired with Nango's AI Function Builder to automate much of the transition process, including reading upstream APIs, writing, and testing functions. Key steps include setting up a Nango project, updating OAuth configurations, migrating authentication and tool calls, and implementing webhook-driven syncs in place of Composio's triggers. The guide also introduces Nango's new data sync capabilities for durable data management and outlines how to configure per-customer settings using Nango's connection metadata. Developers are advised to gradually shift traffic from Composio to Nango, leveraging feature flags and detailed logging for validation before completing the migration. The guide emphasizes the advantages of Nango's runtime for handling token refresh, concurrency, and retries while offering insights into self-hosting options for enterprise users.

Composio and Nango are platforms offering distinct approaches for integrating AI agents with tools and APIs. Composio provides a catalog of around 1,000 pre-built tools for AI agents through a managed MCP URL, making it suitable for personal or internal productivity tools that do not require customization beyond the catalog's capabilities. In contrast, Nango is a code-first API integration platform that allows for the creation and deployment of custom tool calls and integrations via coding agents like Claude, Cursor, and Codex. Nango supports over 800 APIs, offering features such as data syncs, webhook processing, and white-label authentication, catering to production AI teams who need customizable, scalable solutions. While Composio's tools are closed source and limited to catalog offerings, Nango's open-source platform provides greater flexibility, allowing for detailed observability and compliance with standards such as SOC 2 Type II, GDPR, and HIPAA. Nango is recommended for AI agents that are integral to customer-facing products due to its ability to handle complex integration needs and scalability, whereas Composio suits simpler, internal agent tasks well.

The INVALID_SESSION_ID error in Salesforce API integration arises when a Salesforce REST API call returns a 401 Unauthorized status due to issues like expired tokens, incorrect instance URLs, IP address locks, API Client Control restrictions, revoked sessions, or the org being in Read-Only Application Test Mode. Salesforce requires a valid session, correct REST endpoint, and appropriate network environment for successful REST requests, failing which results in this error. Common solutions include refreshing tokens using the refresh token from the initial OAuth response, using the correct instance URL from the token response, disabling IP locks for backend integrations, allowing the Connected App at the org level, and prompting reauthentication if a session is revoked. Proactive measures involve refreshing tokens before expiration, using instance URLs from token responses, and managing concurrency during token refreshes. Tools like Nango can automate handling these issues by managing token refreshes, instance URL enforcement, and providing observability through logging API calls.

Paragon and Nango are two platforms designed for API integrations, each catering to different needs and user profiles. Paragon is an embedded iPaaS centered around a visual workflow engine, enabling non-technical users to compose integrations through pre-built blocks and a separate tool-calling catalog for AI agents called ActionKit. It is suitable for teams requiring a low-code interface and is particularly beneficial when a visual workflow builder is necessary. However, Paragon's flexibility is limited, and many production controls are gated to its Enterprise plan. In contrast, Nango offers a code-first approach where integrations are crafted as TypeScript functions by engineers or coding agents like Claude Code and Codex, supporting over 800 APIs. It emphasizes real-time data syncs, custom tool calls, and a unified runtime for API auth, webhooks, and data integrations, making it ideal for teams where integrations are core to the product and require coding agents to dynamically build and deploy new integrations. Nango provides open-source access, transparent pricing, and the ability to self-host, appealing to teams needing advanced customization and control.

Merge.dev and Nango offer different approaches to API integrations, with Merge providing a unified API across nine categories and a separate Merge Agent Handler for AI agents, both constrained by fixed schemas and limited customization. Merge's solutions are suited for straightforward integration needs that fit within its pre-built catalog, but they lack flexibility for custom fields and objects, and do not support AI coding agents for new integrations. In contrast, Nango is an open-source platform that allows engineers or AI coding agents to build integrations as code, providing extensive customization and support for over 700 APIs across 30 categories. Nango's cloud runtime ensures secure, scalable operations with features like API authentication, data syncs, webhooks, and a single interface for all integration patterns. For businesses where integrations are a core aspect of the product, and require extensive customization or AI tool calls, Nango's platform is more adaptable, offering real-time observability, white-label authentication, and a unified stack for various integration components.

Just-in-time (JIT) API integrations represent a shift from traditional, manually built API connections to a system where AI coding agents create integrations on demand. This innovation contrasts with the conventional embedded integration platform as a service (iPaaS) approach, which requires human intervention and does not scale efficiently to meet customer demands for numerous tool integrations. Platforms like Nango and Prismatic have begun to support JIT integrations, with Nango providing an open-source solution that accommodates over 700 APIs and allows AI coding agents to build, test, and deploy integrations quickly. Nango's platform is specifically designed to handle large-scale integration demands by utilizing its AI builder skill, enabling runtime consumption through managed code production (MCP) servers, typed tool calls, and durable data syncs. This capability is crucial for SaaS products where AI agents need immediate access to integrations for tasks such as reading CRM data or sending messages. While Prismatic offers a low-code workflow builder with some developer-focused tools, it does not fully support JIT integrations like Nango. Other platforms like Workato Embedded and Pipedream Connect lack the ability to generate new integrations on demand, relying instead on pre-built workflows and connectors. The emergence of JIT API integrations underscores a move towards automated, scalable integration processes, with Nango leading the way in providing a comprehensive solution.

Building API integrations with HubSpot can be challenging, particularly when syncing more than 10,000 contacts from a customer's portal. This process involves creating a durable, resumable sync that only fetches new or changed records, managing numerous user authentication tokens, and handling webhook updates. The guide outlines a method to develop a production-ready HubSpot contacts sync using AI Coding Agents like Claude Code, Cursor, Codex, and the Nango AI Function Builder skill. It suggests a two-phase sync strategy utilizing both HubSpot's basic list endpoint, which has no cap but lacks filtering capabilities, and the search endpoint, which filters by lastmodifieddate but is limited to 10,000 results. The integration requires managing durable checkpoints, resumable execution, OAuth lifecycle, and rate limits, all of which Nango provides through its managed integration platform. The guide also offers a step-by-step process to implement a contacts sync, including setting up OAuth app credentials, deploying the sync, and handling sync-completion webhooks, demonstrating how Nango simplifies the integration process across various APIs.

Building a production-ready HubSpot contacts sync involves addressing the limitations of HubSpot's API endpoints, which restrict searches to 10,000 results and lack filtering capabilities on the basic list endpoint. A two-phase sync approach is recommended, using the basic list endpoint for an initial backfill without a cap, followed by the search endpoint for incremental updates filtered by lastmodifieddate. This solution requires durable checkpoints, resumable execution, and handling OAuth token refreshes, rate limits, and webhooks. Nango provides a platform to simplify this process by offering managed authentication for over 700 APIs, including HubSpot, and tools like the AI Function Builder skill to help generate the necessary sync logic efficiently. The integration is enhanced with infrastructure support for token management, retries, rate limit handling, and webhook routing, making it suitable for syncing not only contacts but also companies, deals, tickets, and more.