HydraFusion cheapens a Copilot request. OmnisVigil governs the whole bill.
GitHub's HydraFusion is a cost-cutting router inside Copilot CLI. By GitHub's own numbers it cuts cost on all three of its benchmarks and holds Opus 5 quality on one of them. That's a real, useful result, and the fact that Microsoft shipped it tells you this problem is worth solving. It also has no budgets, no caps, no kill switch and no attribution, and it stops at the Copilot boundary. OmnisVigil does the other job: it governs AI coding spend across every tool your teams use, whatever router runs underneath.
How they compare
| Dimension | HydraFusion (GitHub Copilot) | OmnisVigil |
|---|---|---|
| What it is | Per-request cost routing inside Copilot CLI | Spend control plane for a whole agent fleet |
| Works with | GitHub Copilot only | Claude Code, Cursor, Codex, direct API, Bedrock, and Copilot spend too |
| Budgets and caps | None | Hard caps per team, repo, agent and task |
| Kill switch | None | Cut off a runaway session on the spot |
| Attribution | None | Per commit, repo, team and model |
| Runaway detection | None | Live, flags a session going vertical against its own history |
| Subscription right-sizing | None | Tells you if you're on the wrong plan |
| Proof of savings | GitHub's own benchmarks | Open, reproducible OmnisBench |
| Pricing | Per token on a Copilot plan | Flat fee, free for one, never a cut of your spend |
| Privacy | Runs through Copilot | Content-free, only metadata leaves the boundary |
Cutting a bill, or governing one
HydraFusion makes a single request cheaper. That's worth having. It has no budgets, no caps, no kill switch and no attribution, so it can't tell a platform lead which squad burned the month's budget by Wednesday, it can't stop an agent stuck in a loop at three dollars instead of three hundred, and it can't hand finance a spend-by-team figure. That's the job OmnisVigil exists to do, and it does it whatever tool the spend came through. A cheaper request is welcome. Controlling the bill is a different job.
Hard caps
A daily or monthly ceiling per team, repo, agent or task. A spike trips it mid-day and pauses the offender, so you find out in minutes, not on the invoice.
Runaway detection and a cut-off
A looping agent shows up as a session going vertical. OmnisVigil flags it live and lets you stop that one session on the spot, keeping its log.
Attribution finance can read
Every dollar rolled up by commit, repo, team and model. Content-free, and never a per-developer scoreboard.
HydraFusion stops at the Copilot boundary
HydraFusion only works inside GitHub Copilot CLI, billed per token on a Copilot plan. If your developers use Claude Code, Cursor, Codex, or hit the Anthropic and OpenAI APIs directly, it can't see them or help them. Most teams run three or four of these at once, so a Copilot-only saving leaves the rest of the bill untouched and adds one more silo to the "which team spent what" question. OmnisVigil reads the whole picture, Copilot spend included, and OmnisRouter routes across all of them with a real local cap and kill switch.
Cheaper everywhere, quality held in one of three
Here are GitHub's own figures, and they're honest about the trade-off. Cost fell on all three benchmarks. Opus 5 quality held on one.
| Benchmark | Cost vs Opus 5 | Quality vs Opus 5 |
|---|---|---|
| TerminalBench 2.1 | 67% lower | up 4.9 points |
| DeepSWE | 36% lower | down 1.5 points |
| CheckpointBench | 65% lower | down 0.1 points |
Cheaper is the easy half to prove. What it costs you in quality is the hard half, and on two of three it cost a little. OmnisVigil's savings don't rest on our own word for that. They ride on the open, reproducible OmnisBench, which measures which work needs a frontier model on fresh tasks. We're putting HydraFusion through it and will publish where it lands.
Pick based on the job
HydraFusion
Your team lives entirely inside GitHub Copilot, you want a lower per-request cost with no setup, and you don't need budgets, caps or reporting.
OmnisVigil
You run more than one coding tool, you need spend attributed by team and repo, budgets that hold and a kill switch, and you want one honest view finance can read.
See it on your own bill
OmnisVigil is in early access and free for one. Sign in, and that sets up your workspace. Run OmnisRouter in collect mode on a machine using your Claude subscription. It reads your usage read-only, reprices it, and shows what routing would have saved and where the runaways were. The first number you see is your own.