Agent recipes

Copy-paste workflows for LLM agents and automation. All commands assume:

export REPO=/path/to/repo   # contains .rgbuilder/ after discover

JSON shapes / field tables: json-api.md

jq field contract: use the exact field names from json-api.md (e.g. direct_callers_count, not direct_caller_count). Smoke-test recipes after schema bumps.

Recipe 1 — Orient in an unfamiliar repo

rg-build -r "$REPO" discover .
rg-build -r "$REPO" -f json discover . | jq '.metrics'
rg-build -r "$REPO" -f json gql --macro-name all_functions unused | jq '.count'
rg-build -r "$REPO" -f json gql --macro-name all_communities unused | jq '.rows[:5]'
rg-build -r "$REPO" -f json metrics --pagerank | jq '.rows[:10]'

Use when: first turn on a codebase; replaces reading directory trees.

Recipe 1b — Named communities

rg-build -r "$REPO" communities list
rg-build -r "$REPO" -f json gql 'MATCH (c:Community) RETURN c' | jq '.rows[:10]'
# members of community 12 (id from list / communities.json):
rg-build -r "$REPO" -f json gql "MATCH (f:Function) WHERE f.community_id = '12' RETURN f LIMIT 20"
# optional: refresh heuristic labels into analysis_results.bin
rg-build -r "$REPO" communities label --write

Use when: mapping subsystems without reading communities.json by hand. Labels are heuristic (package / path / token); they are not written into the topology graph.

Recipe 2 — Before editing a symbol

SYMBOL=ShoppingCartService
rg-build -r "$REPO" -f json blast-radius "$SYMBOL" | jq '{
  score: .metrics.score,
  direct_callers: .metrics.direct_callers_count,
  impact_zone: .metrics.impact_zone_size
}'
rg-build -r "$REPO" -f json blast-radius "$SYMBOL" --depth 3 | jq '.topology.direct_callers[:10]'

If the name is ambiguous, disambiguate:

rg-build -r "$REPO" blast-radius process --class ShoppingCartService

Use when: agent plans a refactor or bugfix; avoids missing upstream callers.

Recipe 3 — Find entrypoints / APIs

rg-build -r "$REPO" -f json gql \
  "MATCH (n:Function) WHERE n.name LIKE '*Endpoint' RETURN n LIMIT 20" \
  | jq '.rows[].n.name'

Use when: tracing HTTP handlers or CLI entrypoints.

Recipe 3b — Natural-language function discovery

rg-build -r "$REPO" semantic index
# Offline / no ONNX: add --embedder vocab   (or --embedder hash)
rg-build -r "$REPO" -f json semantic query "shopping cart checkout" --limit 10 \
  | jq '.hits[] | {name, file_path, score: .fused_score}'
# Fusion is on by default; add --keyword-and to require every query token to match
rg-build -r "$REPO" -f json semantic query "OrderService validate" --keyword-and \
  | jq '.hits[:5]'

Use when: the agent knows intent but not exact symbol names; complements GQL LIKE patterns.

Recipe 4 — Call chain neighborhood

rg-build -r "$REPO" -f json gql \
  "MATCH (a:Function)-[:CALLS*1..3]->(b:Function) RETURN a,b LIMIT 50"

Use when: understanding feature locality without opening every file.

Recipe 5 — Data-flow check at a line (needs discover --with-cfg)

rg-build -r "$REPO" discover . --with-cfg
rg-build -r "$REPO" -f json slice \
  src/main/java/com/example/Service.java \
  --line 42 --variable request --function handleRequest \
  | jq '.lines'

Note: --function is the method name, not the class name.

Use when: verifying what affects a variable before changing logic.

Recipe 6 — Taint sanity check

rg-build -r "$REPO" discover . --with-cfg
rg-build -r "$REPO" -f json slice src/.../Controller.java \
  --line 30 --variable param --function handle --taint | jq '.flows'

Use when: security-sensitive edits (user input → sink).

Recipe 7 — Migration batch planning

rg-build discover . --with-cfg --with-security --with-taint --with-dashboard --with-harmonic --export-migration-hints
# Prefer root plan from --export-migration-hints; dashboard copy exists when --with-dashboard ran
jq '.packages[:10]' "$REPO/.rgbuilder/migration_plan.json"
rg-build serve --open   # Migration tab for interactive tuning

Use when: monolith extraction ordering for humans or agents.

Recipe 8 — CI policy on a branch

cp docs/examples/policy-strict.json policy.json
rg-build -r "$REPO" -f json check --policy-file policy.json
# exit 1 → violations in .violations[]

Use when: blocking PRs that touch high-impact symbols.

Recipe 9 — HTTP session (many queries)

rg-build -r "$REPO" serve &
curl -sS -X POST http://127.0.0.1:8080/api/query \
  -H 'Content-Type: application/json' \
  -d '{"query":"MATCH (n:Function) RETURN n LIMIT 5"}' | jq '.count'

See http-api.md.

Recipe 10 — Export subgraph for external tools

# Filter syntax (not GQL MATCH):
rg-build -r "$REPO" export --export-format graphml \
  --export-output service.graphml --query "name:ShoppingCartService"
rg-build -r "$REPO" export --export-format mermaid \
  --export-output all-calls.mmd --query all

Use when: handing a neighborhood to GraphML/Gephi or docs.

Recipe 11 — DTO / cart mutation safety (hybrid CPG)

rg-build -r "$REPO" discover . --with-cfg
# Optional fidelity: --with-dfg-loops  --with-ast-skeleton

# CoolStore ShoppingCart (ecommerce-* fixtures) — non-constructor field writes:
rg-build -r "$REPO" -f json cpg mutations --type ShoppingCart --exclude-ctors

# Same pattern for a DTO / record candidate (substitute your type name):
# rg-build -r "$REPO" -f json cpg mutations --type OrderDTO --exclude-ctors

# After picking a hit at file:line, forward flows on the receiver:
rg-build -r "$REPO" -f json cpg flows \
  src/main/java/com/example/ecommerce/coolstore/service/ShoppingCartService.java \
  --line 75 --variable sc --function priceShoppingCart --direction forward --with-alias

# Optional: coarse syntax tree for the function
rg-build -r "$REPO" -f json cpg ast priceShoppingCart

# Optional: export L_repo (+ L_proc if archived) for Joern/Neo4j tooling
rg-build -r "$REPO" cpg export --format graphson --output cart-cpg.json --path-contains coolstore/

Use when: proving immutability before converting a mutable cart/DTO to a record, or locating pricing side effects on ShoppingCart. Empty mutations ⇒ no typed non-ctor field writes found (unresolved receivers excluded unless --include-unresolved). On C fixtures use the struct typedef (shopping_cart_t). Requires --with-cfg. --with-alias expands may-alias names (copies + field bases). See User Guide §10 and hybrid-cpg-plan.md.

See also

• AGENTS.md
• User Guide