HarnessRouter (YC S23) — The world's first unified interface for agent harnesses
Before you sell to, join or invest in HarnessRouter
MentionFox check on HarnessRouter: only 1 source on file so far (checked 6 November 2026). Run a full check before you rely on it. mentionfox.com/c/funding/yc-harnessrouter
Build agent-powered products without rebuilding the runtime infrastructure. HarnessRouter is the world's first unified interface for agent harnesses, connecting your app to Codex, Claude Code, Hermes, DeepSeek Harness, and other supported harnesses through one API.
HarnessRouter is a Y Combinator company in the Summer 2023 batch. Its directory entry describes it as: The world's first unified interface for agent harnesses. The founder listed is Richard Song (Founder) (Y Combinator directory entry, June 22, 2023).
Get an email when HarnessRouter changes status, grows its team or files a funding notice. One email first to confirm; nothing else until you click it. At most one a day, one click to stop. Free for up to 3 companies.
Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
Build agent-powered products without rebuilding the runtime infrastructure. HarnessRouter is the world's first unified interface for agent harnesses, connecting your app to Codex, Claude Code, Hermes, DeepSeek Harness, and other supported harnesses through one API.
HarnessRouter Cloud runs tasks in isolated, serverless sandboxes and handles sessions, streaming, files, artifacts, recovery, and execution tracing. Teams can compare harness and model configurations on their own tasks to choose the right balance of quality, latency, and cost.
Use the managed Cloud or self-host the Apache 2.0 Community Edition on infrastructure you control. Both implement the Unified Harness Protocol (UHP).
Richard Song
Founder
Founders, titles and bios as the company published them. Photographs are our own copies of the ones on that record, so they do not break when the original link expires.
One of 348 companies held here in B2B › Infrastructure.
No investor is drawn from a Form D — the form states how many invested and never who. The one investor on this graph is named because a batch has exactly one.
Want the whole picture on HarnessRouter?
Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
A Full Report on HarnessRouter: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on HarnessRouter covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
1 cited source found
Plus the sections for what you are deciding, which you pick after ordering.
You get an alert in MentionFox the next time this company shows up.
Is this you?
If you're behind HarnessRouter: acceptance into a YC batch is one of the few weeks a young company gets looked up by people who matter — investors, other founders, press. FoxPlug turns the commits, deploys, and releases you're already making into that story automatically, so anyone who looks finds something current. GetFoxChat puts a guide on your own site so the people YC's own page just sent you don't read one line and leave.
HarnessRouter (YC S23) — The world's first unified interface for agent harnesses. MentionFox, 2026-11-06. https://mentionfox.com/funding/yc-harnessrouter
