POC: structured api interface

.claude/skills/gitnexus/gitnexus-cli/SKILL.md

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+---
+name: gitnexus-cli
+description: "Use when the user needs to run GitNexus CLI commands like analyze/index a repo, check status, clean the index, generate a wiki, or list indexed repos. Examples: \"Index this repo\", \"Reanalyze the codebase\", \"Generate a wiki\""
+---
+
+# GitNexus CLI Commands
+
+All commands work via `npx` — no global install required.
+
+## Commands
+
+### analyze — Build or refresh the index
+
+```bash
+npx gitnexus analyze
+```
+
+Run from the project root. This parses all source files, builds the knowledge graph, writes it to `.gitnexus/`, and generates CLAUDE.md / AGENTS.md context files.
+
+| Flag           | Effect                                                           |
+| -------------- | ---------------------------------------------------------------- |
+| `--force`      | Force full re-index even if up to date                           |
+| `--embeddings` | Enable embedding generation for semantic search (off by default) |
+| `--drop-embeddings` | Drop existing embeddings on rebuild. By default, an `analyze` without `--embeddings` preserves them. |
+
+**When to run:** First time in a project, after major code changes, or when `gitnexus://repo/{name}/context` reports the index is stale. In Claude Code, a PostToolUse hook detects staleness after `git commit` and `git merge` and notifies the agent to run `analyze` — the hook does not run analyze itself, to avoid blocking the agent for up to 120s and risking KuzuDB corruption on timeout.
+
+### status — Check index freshness
+
+```bash
+npx gitnexus status
+```
+
+Shows whether the current repo has a GitNexus index, when it was last updated, and symbol/relationship counts. Use this to check if re-indexing is needed.
+
+### clean — Delete the index
+
+```bash
+npx gitnexus clean
+```
+
+Deletes the `.gitnexus/` directory and unregisters the repo from the global registry. Use before re-indexing if the index is corrupt or after removing GitNexus from a project.
+
+| Flag      | Effect                                            |
+| --------- | ------------------------------------------------- |
+| `--force` | Skip confirmation prompt                          |
+| `--all`   | Clean all indexed repos, not just the current one |
+
+### wiki — Generate documentation from the graph
+
+```bash
+npx gitnexus wiki
+```
+
+Generates repository documentation from the knowledge graph using an LLM. Requires an API key (saved to `~/.gitnexus/config.json` on first use).
+
+| Flag                | Effect                                    |
+| ------------------- | ----------------------------------------- |
+| `--force`           | Force full regeneration                   |
+| `--model <model>`   | LLM model (default: minimax/minimax-m2.5) |
+| `--base-url <url>`  | LLM API base URL                          |
+| `--api-key <key>`   | LLM API key                               |
+| `--concurrency <n>` | Parallel LLM calls (default: 3)           |
+| `--gist`            | Publish wiki as a public GitHub Gist      |
+
+### list — Show all indexed repos
+
+```bash
+npx gitnexus list
+```
+
+Lists all repositories registered in `~/.gitnexus/registry.json`. The MCP `list_repos` tool provides the same information.
+
+## After Indexing
+
+1. **Read `gitnexus://repo/{name}/context`** to verify the index loaded
+2. Use the other GitNexus skills (`exploring`, `debugging`, `impact-analysis`, `refactoring`) for your task
+
+## Troubleshooting
+
+- **"Not inside a git repository"**: Run from a directory inside a git repo
+- **Index is stale after re-analyzing**: Restart Claude Code to reload the MCP server
+- **Embeddings slow**: Omit `--embeddings` (it's off by default) or set `OPENAI_API_KEY` for faster API-based embedding

.claude/skills/gitnexus/gitnexus-debugging/SKILL.md

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+---
+name: gitnexus-debugging
+description: "Use when the user is debugging a bug, tracing an error, or asking why something fails. Examples: \"Why is X failing?\", \"Where does this error come from?\", \"Trace this bug\""
+---
+
+# Debugging with GitNexus
+
+## When to Use
+
+- "Why is this function failing?"
+- "Trace where this error comes from"
+- "Who calls this method?"
+- "This endpoint returns 500"
+- Investigating bugs, errors, or unexpected behavior
+
+## Workflow
+
+```
+1. gitnexus_query({query: "<error or symptom>"})            → Find related execution flows
+2. gitnexus_context({name: "<suspect>"})                    → See callers/callees/processes
+3. READ gitnexus://repo/{name}/process/{name}                → Trace execution flow
+4. gitnexus_cypher({query: "MATCH path..."})                 → Custom traces if needed
+```
+
+> If "Index is stale" → run `npx gitnexus analyze` in terminal.
+
+## Checklist
+
+```
+- [ ] Understand the symptom (error message, unexpected behavior)
+- [ ] gitnexus_query for error text or related code
+- [ ] Identify the suspect function from returned processes
+- [ ] gitnexus_context to see callers and callees
+- [ ] Trace execution flow via process resource if applicable
+- [ ] gitnexus_cypher for custom call chain traces if needed
+- [ ] Read source files to confirm root cause
+```
+
+## Debugging Patterns
+
+| Symptom              | GitNexus Approach                                          |
+| -------------------- | ---------------------------------------------------------- |
+| Error message        | `gitnexus_query` for error text → `context` on throw sites |
+| Wrong return value   | `context` on the function → trace callees for data flow    |
+| Intermittent failure | `context` → look for external calls, async deps            |
+| Performance issue    | `context` → find symbols with many callers (hot paths)     |
+| Recent regression    | `detect_changes` to see what your changes affect           |
+
+## Tools
+
+**gitnexus_query** — find code related to error:
+
+```
+gitnexus_query({query: "payment validation error"})
+→ Processes: CheckoutFlow, ErrorHandling
+→ Symbols: validatePayment, handlePaymentError, PaymentException
+```
+
+**gitnexus_context** — full context for a suspect:
+
+```
+gitnexus_context({name: "validatePayment"})
+→ Incoming calls: processCheckout, webhookHandler
+→ Outgoing calls: verifyCard, fetchRates (external API!)
+→ Processes: CheckoutFlow (step 3/7)
+```
+
+**gitnexus_cypher** — custom call chain traces:
+
+```cypher
+MATCH path = (a)-[:CodeRelation {type: 'CALLS'}*1..2]->(b:Function {name: "validatePayment"})
+RETURN [n IN nodes(path) | n.name] AS chain
+```
+
+## Example: "Payment endpoint returns 500 intermittently"
+
+```
+1. gitnexus_query({query: "payment error handling"})
+   → Processes: CheckoutFlow, ErrorHandling
+   → Symbols: validatePayment, handlePaymentError
+
+2. gitnexus_context({name: "validatePayment"})
+   → Outgoing calls: verifyCard, fetchRates (external API!)
+
+3. READ gitnexus://repo/my-app/process/CheckoutFlow
+   → Step 3: validatePayment → calls fetchRates (external)
+
+4. Root cause: fetchRates calls external API without proper timeout
+```

.claude/skills/gitnexus/gitnexus-exploring/SKILL.md

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+---
+name: gitnexus-exploring
+description: "Use when the user asks how code works, wants to understand architecture, trace execution flows, or explore unfamiliar parts of the codebase. Examples: \"How does X work?\", \"What calls this function?\", \"Show me the auth flow\""
+---
+
+# Exploring Codebases with GitNexus
+
+## When to Use
+
+- "How does authentication work?"
+- "What's the project structure?"
+- "Show me the main components"
+- "Where is the database logic?"
+- Understanding code you haven't seen before
+
+## Workflow
+
+```
+1. READ gitnexus://repos                          → Discover indexed repos
+2. READ gitnexus://repo/{name}/context             → Codebase overview, check staleness
+3. gitnexus_query({query: "<what you want to understand>"})  → Find related execution flows
+4. gitnexus_context({name: "<symbol>"})            → Deep dive on specific symbol
+5. READ gitnexus://repo/{name}/process/{name}      → Trace full execution flow
+```
+
+> If step 2 says "Index is stale" → run `npx gitnexus analyze` in terminal.
+
+## Checklist
+
+```
+- [ ] READ gitnexus://repo/{name}/context
+- [ ] gitnexus_query for the concept you want to understand
+- [ ] Review returned processes (execution flows)
+- [ ] gitnexus_context on key symbols for callers/callees
+- [ ] READ process resource for full execution traces
+- [ ] Read source files for implementation details
+```
+
+## Resources
+
+| Resource                                | What you get                                            |
+| --------------------------------------- | ------------------------------------------------------- |
+| `gitnexus://repo/{name}/context`        | Stats, staleness warning (~150 tokens)                  |
+| `gitnexus://repo/{name}/clusters`       | All functional areas with cohesion scores (~300 tokens) |
+| `gitnexus://repo/{name}/cluster/{name}` | Area members with file paths (~500 tokens)              |
+| `gitnexus://repo/{name}/process/{name}` | Step-by-step execution trace (~200 tokens)              |
+
+## Tools
+
+**gitnexus_query** — find execution flows related to a concept:
+
+```
+gitnexus_query({query: "payment processing"})
+→ Processes: CheckoutFlow, RefundFlow, WebhookHandler
+→ Symbols grouped by flow with file locations
+```
+
+**gitnexus_context** — 360-degree view of a symbol:
+
+```
+gitnexus_context({name: "validateUser"})
+→ Incoming calls: loginHandler, apiMiddleware
+→ Outgoing calls: checkToken, getUserById
+→ Processes: LoginFlow (step 2/5), TokenRefresh (step 1/3)
+```
+
+## Example: "How does payment processing work?"
+
+```
+1. READ gitnexus://repo/my-app/context       → 918 symbols, 45 processes
+2. gitnexus_query({query: "payment processing"})
+   → CheckoutFlow: processPayment → validateCard → chargeStripe
+   → RefundFlow: initiateRefund → calculateRefund → processRefund
+3. gitnexus_context({name: "processPayment"})
+   → Incoming: checkoutHandler, webhookHandler
+   → Outgoing: validateCard, chargeStripe, saveTransaction
+4. Read src/payments/processor.ts for implementation details
+```

.claude/skills/gitnexus/gitnexus-guide/SKILL.md

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+---
+name: gitnexus-guide
+description: "Use when the user asks about GitNexus itself — available tools, how to query the knowledge graph, MCP resources, graph schema, or workflow reference. Examples: \"What GitNexus tools are available?\", \"How do I use GitNexus?\""
+---
+
+# GitNexus Guide
+
+Quick reference for all GitNexus MCP tools, resources, and the knowledge graph schema.
+
+## Always Start Here
+
+For any task involving code understanding, debugging, impact analysis, or refactoring:
+
+1. **Read `gitnexus://repo/{name}/context`** — codebase overview + check index freshness
+2. **Match your task to a skill below** and **read that skill file**
+3. **Follow the skill's workflow and checklist**
+
+> If step 1 warns the index is stale, run `npx gitnexus analyze` in the terminal first.
+
+## Skills
+
+| Task                                         | Skill to read       |
+| -------------------------------------------- | ------------------- |
+| Understand architecture / "How does X work?" | `gitnexus-exploring`         |
+| Blast radius / "What breaks if I change X?"  | `gitnexus-impact-analysis`   |
+| Trace bugs / "Why is X failing?"             | `gitnexus-debugging`         |
+| Rename / extract / split / refactor          | `gitnexus-refactoring`       |
+| Tools, resources, schema reference           | `gitnexus-guide` (this file) |
+| Index, status, clean, wiki CLI commands      | `gitnexus-cli`               |
+
+## Tools Reference
+
+| Tool             | What it gives you                                                        |
+| ---------------- | ------------------------------------------------------------------------ |
+| `query`          | Process-grouped code intelligence — execution flows related to a concept |
+| `context`        | 360-degree symbol view — categorized refs, processes it participates in  |
+| `impact`         | Symbol blast radius — what breaks at depth 1/2/3 with confidence         |
+| `detect_changes` | Git-diff impact — what do your current changes affect                    |
+| `rename`         | Multi-file coordinated rename with confidence-tagged edits               |
+| `cypher`         | Raw graph queries (read `gitnexus://repo/{name}/schema` first)           |
+| `list_repos`     | Discover indexed repos                                                   |
+
+## Resources Reference
+
+Lightweight reads (~100-500 tokens) for navigation:
+
+| Resource                                       | Content                                   |
+| ---------------------------------------------- | ----------------------------------------- |
+| `gitnexus://repo/{name}/context`               | Stats, staleness check                    |
+| `gitnexus://repo/{name}/clusters`              | All functional areas with cohesion scores |
+| `gitnexus://repo/{name}/cluster/{clusterName}` | Area members                              |
+| `gitnexus://repo/{name}/processes`             | All execution flows                       |
+| `gitnexus://repo/{name}/process/{processName}` | Step-by-step trace                        |
+| `gitnexus://repo/{name}/schema`                | Graph schema for Cypher                   |
+
+## Graph Schema
+
+**Nodes:** File, Function, Class, Interface, Method, Community, Process
+**Edges (via CodeRelation.type):** CALLS, IMPORTS, EXTENDS, IMPLEMENTS, DEFINES, MEMBER_OF, STEP_IN_PROCESS
+
+```cypher
+MATCH (caller)-[:CodeRelation {type: 'CALLS'}]->(f:Function {name: "myFunc"})
+RETURN caller.name, caller.filePath
+```