# Go MCP cutover — full test report

**Run ID:** `2026-09-29T162528Z-go-mcp-cutover`  
**Finished (UTC):** 2026-09-29T16:28:00Z (approx)  
**Subject under test:** Go `verae-mcp-timestamping-server` on ns1 replacing Python  
**Binary:** `/opt/verae/verae-mcp-timestamping-server-go/bin/verae-mcp-timestamping-server`  
**Git (local):** `a249564` (+ Caddy fix for `mcp.georgelambert.org` during this run)  
**Forgejo:** https://git.georgelambert.org/marchon/verae-mcp-timestamping-server-go  

## Executive summary

| Metric | Value |
| --- | --- |
| Cases run | **15** |
| Passed | **15** (after L5/L7 retest) |
| Failed | **0** |
| Go MCP live path | **Healthy** (`127.0.0.1:8000`, embedded NATS `127.0.0.1:4229`) |

Initial run had 2 laptop-auth failures (expired `~/.verae/auth.properties`). After `verae-timestamp login` (expires_at → 2026-09-30T07:32:28-09:00), **L5 and L7 retested PASS**.

## Deploy snapshot

| Setting | Value |
| --- | --- |
| systemd unit | `verae-mcp-timestamping.service` |
| Drop-ins | `go-cutover.conf`, `verae-ai.conf` |
| `VERAE_MCP_PORT` | `8000` |
| `VERAE_NATS_LISTEN` | `127.0.0.1:4229` |
| `VERAE_MCP_REQUIRE_BEARER` | `0` (host-token fallback) |
| `VERAE_AUTH_PROPERTIES` | `/var/lib/verae-mcp/auth.properties` |
| Public hosts | `mcp.verae.ai`, `mcp.veraetime.net`, `mcp.georgelambert.org` → `127.0.0.1:8000` |

**During this run:** `mcp.georgelambert.org` Caddy upstream was corrected from `10.1.10.128:8000` (502) to `127.0.0.1:8000`. A `.bak` file that caused “ambiguous site definition” was moved out of `/etc/caddy/sites/`.

## Results matrix

| ID | Case | Status | Notes |
| --- | --- | --- | --- |
| U1 | Go unit tests (`go test ./...`) | **PASS** | authctx, embednats, ledger, server, tools, veraetime, digest, tsnats |
| U2 | Python client unit tests | **PASS** | 47 passed |
| U3 | Python server unit tests | **PASS** | 34 passed |
| L1 | Public MCP suite (`mcp.verae.ai`) | **PASS** | tools/list (7 tools), global hash_report, local stamp+verify, session valid admin |
| L2 | MCP global stamp (unique digest) | **PASS** | host-token fallback |
| L3 | MCP 20× same digest global stamp | **PASS** | unique=1, same=True, ~3.92s, CID `QmXgqQn8…` |
| L4 | Python `ApplicationClient` via MCP | **PASS** | local stamp, verify, hash_report |
| L5 | `ApplicationClient` direct VeraeTime | **PASS** (retest) | After `verae-timestamp login`; hash_report global ≥1 receipt |
| L6 | CLI `verae-timestamp hash` | **PASS** | 64-hex digest |
| L7 | `transaction_log_test.py` (laptop → API) | **PASS** (retest) | unique 1 / same True; `debug-trace/2026-09-29T163256Z-verae-debug-test/` |
| L8 | `mcp.veraetime.net` tools/list | **PASS** | same Go process |
| L9 | `mcp.georgelambert.org` MCP | **PASS** | after Caddy upstream fix; session OK |
| L10 | `pkg/tsnats` → embedded NATS `:4229` | **PASS** | local stamp via SSH tunnel |
| L11 | Static site pages on `mcp.verae.ai` | **PASS** | `/`, developers, ways, openapi, app, explorer |
| L12 | ns1 loopback 5× global idempotent | **PASS** | unique=1, same CID `QmXgqQn8…` |

## Case details

### U1 — Go unit tests

All packages green. No FAIL lines in `logs/u1-go-unit.txt`.

### U2 / U3 — Python suites

Client 47 passed; server 34 passed. Confirms Application Client and Python GlobalClient libraries still build/test while Go owns production MCP.

### L1 — Public MCP suite (`https://mcp.verae.ai/mcp`)

1. `initialize` → `Mcp-Session-Id` present (stateful).  
2. `tools/list` → `create_user`, `hash_report`, `login`, `session`, `signup`, `stamp`, `verify`.  
3. `hash_report` global on Verae-Debug-Test digest → receipt `QmXgqQn8eu6bpBmJ1Fm8xKUePfLREJdghsUkYijStGjVMQ`.  
4. `stamp` scope=local → receipt issued; `verify` OK.  
5. `session` → `valid: true`, `username: admin`, `role: admin` (host-token keeper).

### L2 / L3 — Global stamp paths

- L2: fresh digest stamped globally without client Bearer (`REQUIRE_BEARER=0`).  
- L3: 20 sequential global stamps of digest `469e6159…` all returned the same CID; elapsed ~3.92s.

### L4 — ApplicationClient (MCP transport)

Local stamp → verify → hash_report through `https://mcp.verae.ai/mcp` succeeded.

### L5 / L7 — Laptop direct VeraeTime

**Initial fail:** expired laptop JWT (`expires_at=2026-09-29T06:20:17-09:00`).

**Fix:** `uv run verae-timestamp login` → new `expires_at=2026-09-30T07:32:28-09:00`, then `check-auth` OK.

**Retest:**
- L5: `ApplicationClient.hash_report(DIGEST, want_scope="global")` → receipts ≥ 1 → **PASS**
- L7: `uv run python scripts/transaction_log_test.py` → unique 1, same True → **PASS**  
  Output: `debug-trace/2026-09-29T163256Z-verae-debug-test/`

### L6 — CLI hash

`verae-timestamp hash` produced a valid SHA-256.

### L8 / L9 — Sibling public hostnames

- `mcp.veraetime.net`: PASS.  
- `mcp.georgelambert.org`: initially 502 (wrong upstream); after Caddy fix → PASS.

### L10 — Embedded NATS client

`pkg/tsnats.Connect(nats://127.0.0.1:14229)` (tunnel to ns1 `:4229`) → `Stamp` scope=local → receipt ID returned.

### L11 — Static docs site

HTTP 200 for index, developers, ways, OpenAPI YAML, app, explorer.

### L12 — On-host MCP idempotency

From ns1 to `127.0.0.1:8000` with `Host: mcp.verae.ai`, 5× global stamp of Verae-Debug-Test → one CID.

## Failures — root cause and remediation

| ID | Root cause | Remediation | Status |
| --- | --- | --- | --- |
| L5 | Expired laptop JWT | `verae-timestamp login` then retest | **Fixed** |
| L7 | Same expired laptop JWT (20× 401) | Same login; retest wrote new debug-trace | **Fixed** |

## Artifacts

| Path | Contents |
| --- | --- |
| `results.csv` | Machine-readable PASS/FAIL |
| `logs/` | Per-case stdout/stderr |
| `logs/deploy-state.txt` | systemd drop-in snapshot |
| `logs/l3-20stamp.txt` | 20× CID list |
| `logs/l7-txlog.txt` | Laptop transaction_log output (401) |

Laptop `transaction_log_test` also wrote:

`verae-mcp-timestamping-server/debug-trace/2026-09-29T162648Z-verae-debug-test/`

## Conclusion

The Go MCP service on ns1 is **production-viable** for AI MCP clients and NATS bulk clients under the tested cases. Public tool parity, local ledger, global VeraeTime via host-token fallback, embedded NATS, and static docs all passed. Remaining fails are local developer credentials for direct API scripts.

## Rollback (reference)

```sh
sudo rm /etc/systemd/system/verae-mcp-timestamping.service.d/go-cutover.conf
sudo systemctl daemon-reload
sudo systemctl restart verae-mcp-timestamping.service
```