# pragent `.opencode/` — the review factory

pragent's review runs on **opencode** (the AI-coding-agent CLI). This directory is
a portable **factory**: the `opencode.json` + `.opencode/` are dropped into a
checked-out copy of the target repo at the PR head sha, then `opencode run` is
launched there. The `pragent` primary agent reviews the diff with real tools
(subagents, LSP/linters via bash, webfetch references) and emits a structured
findings JSON. A thin Python shell posts that JSON back to Gitea as inline
comments + language-highlighted suggested-fix blocks + a summary (dedupe + anchor validation stay
deterministic in Python).

## Layout

```
opencode.json              provider (headroom → glm-5.2:cloud), model, lsp, permission, default_agent
.opencode/
  agents/
    pragent.md             PRIMARY reviewer — reads .pragent/brief.md, runs linters, emits findings JSON
    security.md            subagent — injection/auth/secrets/supply-chain lens (dormant)
    tests.md               subagent — missing/weak test coverage lens (dormant)
    perf.md                subagent — N+1 / O(n²) / hot-path lens (dormant)
  skills/
    review-methodology/SKILL.md   severity rubric, what to report, anchoring, trust boundary
    findings-schema/SKILL.md      the exact output JSON shape
    attention-tiering/SKILL.md    trivial/lite/full/oversized + the budget each tier gets
    linter-playbook/SKILL.md      per-ecosystem check commands + turning diagnostics into findings
    security-lens/SKILL.md        inline security checklist + the source→sink test
    malicious-change/SKILL.md     hostile-PR detection: injection at the reviewer, install hooks, backdoors
    comment-craft/SKILL.md        how to write problem/fix/suggestion so a maintainer can act
  commands/
    review.md              /review slash command (local interactive use)
  README.md                this file
```

## How a review runs

```mermaid
flowchart TD
  WH["webhook_server.py<br/>HMAC + AI-REVIEW gate + dedupe"] --> RP["ai_review.review_pr"]
  RP --> ARCH["fetch repo archive @ head sha<br/>→ /tmp/pragent-work/<repo>-<sha>"]
  ARCH --> BRIEF["write .pragent/brief.md<br/>(title, body, diff, config, prior, sha)"]
  BRIEF --> DROP["drop opencode.json + .opencode/ into workdir"]
  DROP --> OC["opencode run --pure --agent pragent --dir <workdir><br/>--model headroom/glm-5.2:cloud"]
  OC --> PR["pragent primary<br/>load skills · run linters · read code · delegate lenses"]
  PR --> JSON["final message: summary + ```json findings```"]
  JSON --> PARSE["ai_review.parse_review_output<br/>{summary, findings}"]
  PARSE --> ANCHOR["parse_diff_anchors → split_findings"]
  ANCHOR --> POST["post_inline_review<br/>summary + inline lang-tagged fix block + ref links + sha marker"]
```

## Lean by default

`attention-tiering` is the cost governor: it classifies every PR as `trivial` /
`lite` / `full` / `oversized` before any file is read, and each tier caps file
reads, linter runs, and subagent fan-out. The `pragent` primary does the whole
review in one pass for small/medium diffs (no subagent calls) and delegates to
`@security` / `@tests` / `@perf` ONLY at `full`/`oversized` when the lens has
real surface. Skills are loaded conditionally for the same reason — each one is
input tokens. Subagent recursion is capped by the primary's `steps` budget.

`pilot/cost_model.py` turns those tier assumptions into a per-PR and per-month
cost figure for any provider — run it after changing the factory to see what the
change costs.

`--pure` is passed at runtime so the reviewer doesn't load the host user's heavy
global opencode plugins (supermemory/dcp/morph/pty) which hang cold-start. In the
deploy pod there's no global config, so `--pure` is a no-op there — but it keeps
host-local runs deterministic.

## Extending the factory

### Add a review lens (subagent)

1. Create `.opencode/agents/<name>.md` with `mode: subagent`, `hidden: true`, a
   `description`, and a read-only `permission` (deny edit/write, allow bash/webfetch,
   `task: deny` so it can't recurse). The body is its system prompt; end it by
   requiring the same findings-JSON shape.
2. Allow it in the primary's `permission.task` list in `pragent.md`:
   ```yaml
   task:
     "*": "deny"
     "security": "allow"
     "tests": "allow"
     "<name>": "allow"      # add this
   ```
3. Mention in `pragent.md`'s "Delegate on heavy diffs" step when to invoke it.

That's it — the primary can now `@<name>` it via the Task tool. It stays dormant
(the primary decides when), so adding it costs nothing for small PRs.

### Add a skill

1. `mkdir .opencode/skills/<name> && touch .opencode/skills/<name>/SKILL.md`
2. Frontmatter: `name: <name>` (kebab-case, matches dir), `description:` (specific
   enough for the agent to pick it). Body = the knowledge.
3. Refer to it from `pragent.md` ("Call the `skill` tool for `<name>`").

Per-language expertise is free: the host user already has 29 global skills
(golang-*, react-*, k8s, terraform, testing, typescript, …). opencode
auto-discovers them via the `skill` tool — the pragent primary loads a matching
one when the repo's language fits. To ship a pragent-specific one, just drop it
here.

### Change the output shape

Edit `.opencode/skills/findings-schema/SKILL.md` (the schema doc) AND the Python
parser in `pilot/ai_review.py` (`parse_findings`) + the renderers
(`inline_comment_body`, `summary_bullets`, `format_review_body`). Keep them in
sync — the parser is tolerant but the agent and parser must agree on field names.

### Switch model / provider

Edit `opencode.json` `provider` + `model`. The provider points at the on-network
headroom proxy (`http://<model-proxy-host>:8789/v1`, Anthropic `/v1/messages` format,
`apiKey: ollama`) → `glm-5.2:cloud`. To use a different model, add a provider and
reference it as `<provider>/<model-id>`.

## Local one-shot review (no webhook)

```bash
cd ~/Projects/pragent
opencode run --pure --agent pragent --dir . \
  --model headroom/glm-5.2:cloud \
  "Read .pragent/brief.md if present, else review \`git diff HEAD\`, and output findings."
```

Or in the TUI: `/review` (uses `.opencode/commands/review.md`).

## Engine flag

`PRAGENT_ENGINE=opencode` (default once wired) uses this factory. `=ollama`
falls back to the legacy direct model call in `pilot/ai_review.py`. The two
share all Gitea I/O, dedupe, and posting logic.