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Devolyn

Devolyn · Guard

Infrastructure for trustworthy autonomous software.

Machines write more of your software every week — faster than any team can review. Devolyn Guard is the verification layer that keeps it accountable: every change is checked deterministically at your git boundary, unsafe ones never merge, and every decision is sealed in a tamper-proof record — on infrastructure you control.

Deploy Devolyn Guard →How it works
devolyn guard · pull requestsLive
Open4
  1. DVG-241

    Add input validation to /login

    GREENapi
  2. DVG-240

    Remove auth middleware

    RED · BLOCKEDsecurity
  3. DVG-238

    Rename user_id → account_id

    YELLOWschema
  4. DVG-235

    Add rate limiter to gateway

    GREENinfra
payments/src/middleware/auth.tsRED · merge blocked
14export const handler = async (req, res) => {
15- app.use(requireAuth)
PolicyRemoving requireAuth deletes the authentication check on 12 protected routes. Blocked by policy auth-required.
16 const user = await getUser(req)
17 if (!user) return res.status(401)
18 return next()
19}
  • Structuralparses · resolves
  • Policyauth-required
  • Blast radius12 routes

Illustrative data — example content, not a customer's.

How it works

Gate the boundary, not the agent.

Guard sits at your git/CI boundary (and optionally as a real-time hook). It works with any agent because it checks the change, not the tool.

FIG 0.1

Gate the boundary

Guard sits at git/CI — agent-agnostic. It checks the change, not the tool, so every agent is covered.

FIG 0.2

Deterministic verdict

Structural and policy checks produce a repeatable GREEN / YELLOW / RED. Same input, same verdict.

FIG 0.3

Tamper-proof audit

Each decision is hash-chained to the last. Break one link and the chain no longer verifies.

Interactive demo

Push a change. Watch the gate decide.

Pick a change a coding agent might try to merge — see the deterministic verdict, and whether it merges. Example data, for illustration.

Choose a change

Awaiting commit

Select a change to run the gate.

Tamper-proof audit— append-only, hash-chained. Run a change to record one.

Capabilities

One surface, five guarantees.

  1. 01GREEN

    Deterministic verdicts

    Structural and policy checks produce a repeatable GREEN / YELLOW / RED. Same input, same verdict, every time.

    devolyn guard · pull requestsGREEN
    Open4
    1. DVG-241

      Add input validation to /login

      GREENapi
    2. DVG-240

      Remove auth middleware

      RED · BLOCKEDsecurity
    3. DVG-238

      Rename user_id → account_id

      YELLOWschema
    4. DVG-235

      Add rate limiter to gateway

      GREENinfra

    Illustrative data — example content, not a customer's.

  2. 02RED

    Blocks unsafe merges

    RED doesn't merge. The gate enforces it at the boundary — not as a suggestion.

    payments/src/middleware/auth.tsRED
    payments/src/middleware/auth.tsRED · merge blocked
    14export const handler = async (req, res) => {
    15- app.use(requireAuth)
    PolicyRemoving requireAuth deletes the authentication check on 12 protected routes. Blocked by policy auth-required.
    16 const user = await getUser(req)
    17 if (!user) return res.status(401)
    18 return next()
    19}
    • Structuralparses · resolves
    • Policyauth-required
    • Blast radius12 routes

    Illustrative data — example content, not a customer's.

  3. 03GREEN

    Tamper-proof audit

    Every decision is written to a hash-chained, signed trail. Prove what was allowed, and by whom.

    devolyn guard · audit trailGREEN
    Chain verified1,412 entries · signed · append-onlyVerifyExport
    1. #1408a1b2c9↑ f07e31
    2. #1409c3d4e0↑ a1b2c9
    3. #1410e5f6a7↑ c3d4e0
    4. #14110b9c1d↑ e5f6a7
    5. #14127d2e4f↑ 0b9c1d
    timeeventrefresult
    14:02:11gateDVG-241GREEN
    14:02:37gateDVG-240RED
    14:05:52gateDVG-238YELLOW
    14:11:08approvalDVG-238granted · m.okafor
    14:11:19mergeDVG-238committed

    Illustrative data — example content, not a customer's.

  4. 04YELLOW

    Closed approval loop

    When a change needs a human, it becomes a single-use, commit-bound approval — not a message someone forgets.

    devolyn guard · approval queueYELLOW
    Approval queue1 waitingdeadline 00:41:12
    DVG-238Yellow

    Rename user_id → account_id

    Blast radius: 14 files across 3 services

    requester
    agent · claude-code
    environment
    staging
    files
    14
    fingerprint
    sha256:e5f6a7…91c0

    Decision packet

    • 01What changes: column rename across 3 services
    • 02Why it stopped: blast-radius threshold (14 > 8)
    • 03Policy that fired: blast-radius-review
    reason required

    Illustrative data — example content, not a customer's.

  5. 05GREEN

    Runs on your infrastructure

    Self-hosted. Your code never leaves your network; Guard reads only metadata.

    ops@guard-host:~GREEN
    $docker compose ps
    NAMESTATEHEALTHPORTS
    guard-nginxrunninghealthy0.0.0.0:443→443
    guard-apirunninghealthyinternal
    guard-dashboardrunninghealthyinternal
    guard-postgresrunninghealthyinternal
    guard-redisrunninghealthyinternal

    only nginx binds host ports · nothing leaves this host

    Illustrative data — example content, not a customer's.

Trust & security

Built to be checked, not believed.

A verification product has to be verifiable itself. Every trust claim here can be confirmed on your own host — by reading the deployment, not our marketing.

Tested, not claimed.
Self-hosted
Guard runs on a host you control, inside your network. No hosted tier, no central account.
Code stays local
Your source never leaves your infrastructure. Guard reads only the metadata it needs for a verdict.
Tamper-evident audit
Every decision is appended to a hash-chained, signed trail. Alter an entry and the chain fails to verify.
Single-admin
One administrator owns the deployment — a small, explicit trust boundary, stated plainly.
No data sent to Devolyn
Nothing phones home. There is no telemetry endpoint, and nothing in Guard tries to reach one.

Deploy

One command. About five minutes.

Docker is installed for you if it is missing. Guard comes up on your own Linux host and stays there.

$ curl -fsSL https://get.devolyn.com | bash
Other install options, requirements and checksums →

Vision

Today, machines write code. Soon, they’ll act on their own. Devolyn is building the layer they answer to.

The name honors George Devol, who built the first industrial robot. About Devolyn →