Coevolve turns a goal into a planned, executed, and verified run across a fleet of different models. The verdict on every change is what the code actually did when it ran — tests, type checks, schemas, real execution in an isolated sandbox — not a model’s opinion of its own output.
bash — install
# macOS, Linux, or WSLgit clone https://github.com/SourceShift/coevolve.git
cd coevolve
make install
context fragments · 10,902 real sessions · live org memory
MEASURED
6,374
paper research map · 79 arXiv IDs cross-checked, 0 altered
// the run lifecyclea goal in → a verified outcome out
// why this exists
The bottleneck moved from generation to validation.
Ship agent work you can trust, at a cost you can defend, on a system that gets sharper on your codebase the more you run it.
AI agents now write code faster than any team can review it. An agent that writes its own tests and then grades itself produces output that agrees with itself — fluent, green-looking, and wrong often enough to break production.
And the naive fix — send everything to a frontier model, run it many times — makes the bill grow faster than the unit price falls. Coevolve is built for the world after “make it generate.”
// why now
RELIABILITY
81%
of enterprise technology leaders report an increase in production issues linked to AI-generated code.
CloudBees, 2026 State of Code Abundance
COST ROUTING
>2×
cost cut by routing between a strong and weak model, without compromising quality — the lever Coevolve automates against a verification bar.
RouteLLM, arXiv:2406.18665
GOVERNANCE
3blockers, every time
Most agent pilots stall on the same three things — evaluation, reliability, and governance — which Coevolve treats as runtime primitives.
the three layers, wired in
// what an orchestration framework won't do for you
Wiring agents into a graph is commodity. Coevolve adds the three layers that decide whether the work is shippable.
01
It verifies correctness — it doesn’t just orchestrate
The source of truth for a change is its execution outcome, captured in an isolated runtime — Coevolve’s Crucible, built over Prime Intellect’s MIT-licensed verifiers.
✓
Execution-anchored reward.Scored on what it did — did the test run, did the assertion pass. An LLM judge may only veto a passing result, never fabricate one.reward_from_status
✓
A real failure ≠ a broken harness.The runtime tells a genuine assertion failure from a broken test or environment, so a correct patch is never rejected because the probe had a typo.
✓
Non-regression is certified.Candidates that would break a previously-solved, held-out task are blocked before they ship.cli/apply.py
⚠
A run with no meaningful check is reported as vacuous, not silently successful.
02
It governs cost across a pool of models
You don’t pay frontier prices for work a cheaper model can pass.
→
Heterogeneous dispatch.Bring your own providers — OpenAI/Codex, MiniMax, Kimi, GLM, Anthropic, or any OpenAI-compatible endpoint — and route each node to a lane by role.
→
Cost-optimizing routing policies.Selectable strategies from frontier_only to cheap_only to learning_governed — route to the cheapest lane that still clears the verification bar.COEVOLVE_ROUTING_POLICY
→
Hard cost controls.A daily-spend circuit breaker, a periodic cost-pause sentinel an operator must approve, and a wall-clock deadline budget — so an autonomous run can’t quietly burn your account.
COEVOLVE_ROUTING_POLICY
frontiercheap
{{ row.role }}
{{ row.laneLabel }}
run cost{{ routingTotalLabel }}
{{ routingNote }}
03
It learns from what actually verified
Every run leaves a trail of verified outcomes, and the system feeds that signal back — so it gets sharper on your codebase the more you run it.
↻
Cost-free bandit routing.A contextual bandit adjusts which lane gets each role next time, from real advantage — no extra model calls.lane_router.py
↻
GRPO writeback.Group-relative writeback and textual-gradient prompt evolution improve the planner / implementer / reviewer prompts across runs.
↻
Verified-outcome memory.Persists only what passed the gates, so the learned signal is clean rather than noise. A closed learn → apply loop materializes, scores, and non-regression-gates each proposed improvement before it lands.
// the compounding loop, measured
It gets sharper on your codebase the more you run it.
Quality climbs and cost falls together, cycle after cycle. Here is the signal, by subsystem — switch tabs to inspect each one.
Every run yields a verified outcome; that outcome routes the next run to a cheaper model; the signal compounds on your repository.
Correctness-conditional, cost-optimizing, compounding, and open-source — that specific combination is the wedge, and it doesn’t exist together anywhere else today.
// what is in the box
119 shipped capabilities, seven pillars
full code-anchored list in the feature inventory
PILLARWHAT YOU GET
{{ p.num }}{{ p.name }}
{{ p.desc }}
// the observability surface
See why a run passed — or didn’t
127.0.0.1:7090 · coevolve serve
LIVE
RUNS
code-fixa91f
docsb204
refactor-audit7c3d
code-fix55e1
code-fix · a91fSHIP ✓learning_governed · 17 units
RUN DAG
GATE EVIDENCE
✓reward_from_status3/3 assertions passed
✓non-regressionheld-out suite green
✓budget17 / daily 4000 units
LIVE EVENTS · SSE
12:04:03 plan: 4 steps
12:04:09 execute: patch applied
12:04:12 crucible: sandbox up
12:04:15 verify: 3/3 ✓
12:04:16 gate reward: pass
12:04:16 gate non-regress: pass
12:04:16 promote → SHIP
COST / RUN↓ as bandit learns
// start here
Install the full runtime
make install sets up the required OS tools, a checkout-local .venv, the .[full] profile (CLI, local web sidecar, and Crucible), and the per-user command. Dry runs never call a model provider — and it’s safe to re-run after an upgrade.
macOS · Linux · WSL
git clone https://github.com/SourceShift/coevolve.git
cd coevolve
make install
# new terminal, then confirm .venv
coevolve version
Windows PowerShell
# install OS prereqs with winget first# (Python 3.11, Git, jq, yq, SQLite)
py -3 .\scripts\full_install.py
coevolve version
Your first verifier-backed workflow
Start in a real Git repo. A kickoff states the goal, scope, artifact, and verification expectation — then dry-run locally before spending a single token.
bash — dry run, no provider calls
# remember the checkout, then make a project
COEVOLVE_SOURCE="$PWD"mkdir -p ~/coevolve-demo && cd ~/coevolve-demo
git init && coevolve init
# a kickoff = goal + scope + artifact + proofcp"$COEVOLVE_SOURCE/examples/01-hello-world/kickoff.md" ./kickoff.md
# run locally, without provider calls
COEVOLVE_DRY_RUN=1 coevolve run code-fix ./kickoff.md
coevolve validate
Reviewed agents.yaml and authenticated your providers? Drop the flag:
coevolve run code-fix ./kickoff.md
// use Coevolve well
01
Write a verifiable kickoff.
State the target repository, allowed files, intended artifact, and the command or rule that proves success.
02
Dry-run new recipes first.
It checks the lifecycle and artifact paths without model calls — it does not prove the eventual change is correct.
03
Give an agent an oracle.
Prefer an existing test, typecheck, schema, fixture, or observable acceptance criterion over an LLM-only score.
04
Use multiple lenses deliberately.
Heterogeneous review is useful for discovery and diagnosis; it does not replace deterministic verification.
05
Read the evidence before promotion.
Traces are retained and learned from, but automatic promotion is restricted to classes with measurable external evidence.
the discipline
Prefer a real check over a confident opinion. Where there isn’t one, surface the uncertainty.
recipes live in recipes/ — task class + workflow + artifact contract + prompts + verifiers
// honesty by design
Coevolve does not claim a universal oracle.
Where there is no trustworthy external check — a subjective product decision, untestable code — it surfaces uncertainty or asks a person rather than manufacture confidence. The execution oracle is only as strong as what you can run: richest on code with real tests, thinnest on subjective work. That discipline is wired in, not aspirational.
$ coevolve run docs ./kickoff.md
status: vacuous
no meaningful check ran — not silently “successful”
evidence: "none"
<5 samples — Wilson-CI won’t invent a number
rejection → cites evidence trace
every “no” is auditable
// roadmap
NEAR-TERM · OPERATIONAL TRUST
Truthful dispatch telemetry, an error and finish-reason taxonomy, heartbeat/failure handling, capability-aware routing, cost accuracy, and operator intervention policies.
NEXT RESEARCH · VERIFIER-LED ESCALATION (proposal)
Build a library of recovery behaviors from failure analysis, then learn a policy that chooses among a cheap tool call, more planning, a stronger model, or a user interruption — with verified progress as the signal, balanced against compute, latency, and the user’s interruption budget.
// contributing & status
Coevolve is Apache-2.0 and early. Use a dedicated worktree for framework changes, keep a verifier with every behavior claim, and run the focused checks for the surface you change. The workflow and quality gates live in AGENTS.md; direction in GOVERNANCE.md.