Greptile

Greptile builds AI agents that review and test pull requests for software engineering teams. Its reviewer indexes files, functions and dependencies into a codebase graph, then uses parallel agents to investigate changes and their effects beyond the diff. Teams can specify coding standards in plain English, and Greptile also learns conventions from engineers’ review comments. TREX adds execution to this workflow: it runs code in disposable sandboxes and returns screenshots, logs, API traces and execution scripts to help developers assess runtime problems.

Founded in 2023 by Daksh Gupta, Soohoon Choi and Vaishant Kameswaran, Greptile participated in Y Combinator’s Winter 2024 batch. Its early platform helped developers ask questions about large codebases and build internal tools through an API. That repository-context approach now underpins its review system. In TREX’s architecture, the main reviewer delegates specific investigations to agents that inherit its findings while maintaining separate context windows; a model-agnostic harness allows the reviewer and investigating agents to use different model providers.

Greptile supports GitHub, GitLab and Bitbucket, with cloud and self-hosted deployment options, including air-gapped environments. Its MCP integration lets coding agents retrieve review comments and team-specific rules. In September 2025, the company reported reviewing more than 500 million lines of code that month, including work for Brex, Substack and PostHog, and announced a $25 million Series A led by Benchmark.