# Nexttrace

> Nexttrace is an Agent Skill for devops & security published in the nxtrace/NTrace-core repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.

Use NextTrace through its deploy MCP endpoint for traceroute, MTR, MTU discovery, speed tests, IP annotation, GeoIP lookup, and Globalping multi-location traceroute. Trigger when an agent needs network path diagnostics or needs to call NextTrace MCP tools.

- Skill name: `nexttrace`
- Category: [DevOps & Security](https://www.openparable.com/skill/devops-security/1)
- Source: https://github.com/nxtrace/NTrace-core/blob/HEAD/skills/nexttrace/SKILL.md
- Repository: nxtrace/NTrace-core (8,026 GitHub stars when collected)

## SKILL.md

# NextTrace MCP

Use this skill when the user wants route diagnostics through NextTrace or asks how an Agent should call NextTrace.

## Start MCP

NextTrace exposes MCP only as a deploy submode over HTTP. There is no stdio MCP mode.

```bash
nexttrace --deploy --mcp
nexttrace --deploy --mcp --listen 0.0.0.0:1080 --deploy-token "$TOKEN"
```

Endpoint:

```text
http://127.0.0.1:1080/mcp
```

Auth:

- Loopback listen addresses are tokenless by default unless a token is set.
- External listen addresses require a token. If none is provided, NextTrace prints a generated token to stdout.
- MCP/API clients authenticate with `Authorization: Bearer <token>` or `X-NextTrace-Token: <token>`.
- Browser WebUI uses `/auth/login` and an HttpOnly cookie.
- Do not put tokens in URL query strings.

## Workflow

1. Call `nexttrace_capabilities` first when available.
2. Pick the narrowest common tool for the job:
   - Local route: `nexttrace_traceroute`
   - Repeated loss/latency stats: `nexttrace_mtr_report`
   - Probe-level stream records: `nexttrace_mtr_raw`
   - Path MTU: `nexttrace_mtu_trace`
   - Global vantage points: `nexttrace_globalping_trace`
   - Other tools: `nexttrace_speed_test`, `nexttrace_annotate_ips`, `nexttrace_geo_lookup`, `nexttrace_globalping_limits`, `nexttrace_globalping_get_measurement`
3. Prefer `structuredContent`; use text content only as a fallback.
4. Preserve explicit user inputs: `target`, `protocol`, `port`, `source_address`, `source_device`, ASN, location, and `ip_version`. Do not substitute them unless the user asks for a fallback.
5. On errors or missing results, report the exact failure and suggested next step. Do not automatically switch protocol, port, location, ASN, tool, or local/Globalping mode.
6. For full tool schemas and boundaries, read [references/mcp-tools.md](references/mcp-tools.md) and [references/capability-matrix.md](references/capability-matrix.md).
7. For Globalping, read [references/globalping.md](references/globalping.md). For local source/device/TOS behavior, read [references/platform-notes.md](references/platform-notes.md). Use [references/cli-fallback.md](references/cli-fallback.md) only when MCP is unavailable, unsupported, or the user asks for CLI output.
8. Before writing the final answer, use [references/output-templates.md](references/output-templates.md) for a concise Markdown shape.
9. Keep this skill and its references synced with `server/mcp.go` whenever MCP tools or parameters change.

## References

- [MCP tools](references/mcp-tools.md): tool names, inputs, outputs, unsupported parameter families.
- [Globalping](references/globalping.md): worldwide traceroute workflow and comparison guidance.
- [Capability matrix](references/capability-matrix.md): local vs Globalping vs CLI fallback.
- [Output templates](references/output-templates.md): bilingual Markdown report shapes for each MCP tool.
- [CLI fallback](references/cli-fallback.md): commands to use when MCP is unavailable.
- [Platform notes](references/platform-notes.md): OS-specific source, device, TOS, raw-socket details.
- [Validation](references/validation.md): smoke checks and expected behavior.

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Source: https://www.openparable.com/skill/devops-security/nexttrace (OpenParable). Cite the canonical URL above.