customAgents let each repository add its own review agents. Org custom agents invert that: an organization admin defines an agent once in the dashboard, and it runs across the org’s repositories whether or not each repo asks for it.
Use them for standards that are not a per-repo choice — a compliance rule, a security requirement, a house pattern every service must follow.
Find them under Settings → Custom agents. Available on both managed SaaS and self-hosted.
Who can edit
Only organization admins can create or edit org agents. Other members see a read-only view — they can tell what is enforced and why a finding appeared, without being able to change it.Defining an agent
Each agent also records who last edited it and when, so an unexpected finding can be traced to a change rather than argued about.
Enforcement: advisory vs blocking
This is the field to think hardest about.Advisory
Findings appear in the review like any other. They feed the merge-readiness score but do not independently gate anything.
Blocking
A critical finding from this agent fails the check run and requests changes — regardless of the overall merge score.
Scoping and targeting
Scope decides which repositories the agent applies to: all, or an explicit allowlist. Targeting narrows further, within those repositories — the agent runs only when the PR actually touches relevant code:- Path globs — run only when a changed file matches one of these patterns.
- Languages — run only when the PR touches one of these languages.
**/*.tf costs nothing on the PRs that do not touch Terraform, and there is no reason to pay for an LLM call that has nothing to examine.
How org agents combine with repo agents
Org agents run in addition to each repository’s own.mergewatch.yml customAgents — the two sets are unioned.
On a name collision, the org agent wins. A repository cannot disable or override an org agent by defining one with the same name. Repositories can add agents; they cannot remove org ones. That asymmetry is deliberate: an org standard that any repo could opt out of by naming a local agent the same thing would not be a standard.
Cost
Each enabled agent adds one LLM call per review it runs on. Ten org agents scoped to all repositories means up to ten extra calls on every pull request across the organization. The dashboard warns past 10 active agents. It is a soft cap — nothing is blocked — but treat the warning as real: past that point, targeting is no longer optional if you care about review cost and latency. Two levers keep this under control:- Target aggressively. Most org concerns apply to a subset of files, not every PR.
- Consolidate prompts. Three narrow agents that always run together are usually better as one agent with a broader prompt.
Next steps
Per-repo custom agents
The
customAgents block org agents union with.Review behavior
How findings become a merge-readiness score.