The implementation
Once the plan is defined, it’s time to start coding. I just fed OpenAI Codex the prompt as ChatGPT had defined it and generated this version: https://github.com/javiercancela/virtual-world/tree/v1
Just as a test, I used Cursor in Auto mode to add `uv:
Running the code results in this interaction:
Ok, now we need some actual local LLM to test. I deleted my previous llama.cpp install, so I downloaded and compiled it again:
1
2
cmake -B build -DGGML_CUDA=ON
cmake --build build --config Release -j 16
For the model, we use the Qwen3.5 family, with the Unsloth quantization:
1
2
hf download unsloth/Qwen3.5-4B-GGUF --include "Qwen3.5-4B-UD-Q4_K_XL.gguf" --local-dir ./models/Qwen3.5-4B
hf download unsloth/Qwen3.5-9B-GGUF --include "Qwen3.5-9B-UD-Q5_K_XL.gguf" --local-dir ./models/Qwen3.5-9B
The 4B version for routing, the 9B version for the rest.
We run one instance of llama.cpp for each, in different ports. To fit this into my system, I run the 9B model with the GPU and the 4B one with the CPU:
1
2
3
4
5
6
7
8
9
10
11
./llama.cpp/build/bin/llama-server /
-m ./models/Qwen3.5-9B/Qwen3.5-9B-UD-Q5_K_XL.gguf /
--alias Qwen3.5-9B /
--port 8081
CUDA_VISIBLE_DEVICES="" ./llama.cpp/build/bin/llama-server /
-m ./models/Qwen3.5-4B/Qwen3.5-4B-UD-Q4_K_XL.gguf /
-ngl 0 /
-t 8 /
-c 2048 /
--port 8082
I used CUDA_VISIBLE_DEVICES=”” to force using the CPU and avoid compiling this model specifically for the CPU. But to make it work, I had to add the -ngl 0 param too. The option -c 2048 limits the context to use less memory, because context usage for routing is small.
I found an error after trying with the llama servers running:
1
2
3
4
5
6
7
8
9
10
11
12
13
...
slot update_slots: id 3 | task 910 | prompt processing done, n_tokens = 110, batch.n_tokens = 110
slot print_timing: id 3 | task 910 |
prompt eval time = 56.08 ms / 110 tokens ( 0.51 ms per token, 1961.52 tokens per second)
eval time = 2224.34 ms / 128 tokens ( 17.38 ms per token, 57.55 tokens per second)
total time = 2280.42 ms / 238 tokens
slot release: id 3 | task 910 | stop processing: n_tokens = 237, truncated = 0
srv update_slots: all slots are idle
srv stop: cancel task, id_task = 910
srv update_slots: all slots are idle
srv operator(): got exception: {"error":{"code":500,"message":"Failed to parse input at pos 494: ","type":"server_error"}}
srv log_server_r: done request: POST /v1/chat/completions 127.0.0.1 500
I just pasted the log to Claude and asked him to fix it. This is the fixed version: https://github.com/javiercancela/virtual-world/tree/v2.
This is the end result for this version:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
Night Desk
Rain hammers against the steel shutters as Mara Voss leans over her desk, her
eyes fixed on the locked exit door. The only sound is the rhythmic clatter of
keys against the steel cabinet and the soft rustle of paper in the visitor
ledger. She offers a knowing smile, suggesting that the storm outside is just
as trapped as you are inside.
Commands: inspect <object>, talk to Mara, use <item> on <target>, take <item>,
move <object>, inventory, look, help, quit.
> What is the time according to the clock?
Rain drums against the high windows as Mara Voss measures your story, her eyes
fixed on the locked steel cabinet and the sealed exit door. The only things
within reach are the visitor ledger, the coat rack, the framed photo, and the
desk, all set against the cold glow of the office.
> Examine the framed photo
The photograph reveals Mara with a commendation ribbon pinned to her jacket,
while the engraved plaque beneath reads: "Attention kept us alive." It feels
less like sentiment and more like a test, the stark white paper contrasting
with the dim, humming light of the security office.
> Examine the visitor ledger
The ledger lies open on the desk, its final entry underlined twice in stark
red pencil, while the name "Silas Vale" stares back from the visitor's
signature. Mara's sharp eyes are already scanning the page, waiting for you
to confirm whether that name belongs in the report or the witness box.
> Ask Mara about Silas Vale
Rain drums against the high windows as Mara Voss measures your story, her gaze
fixed on the locked steel cabinet and sealed exit door. The only things within
reach are the visitor ledger, the framed photo, the coat rack, and the heavy
steel cabinet that remains stubbornly closed.
> talk to Mara
"The ink on that ledger doesn't dry quickly when someone is watching you, so
why are you still looking at me?" Mara's voice is low and steady, cutting
through the rain outside as she avoids your eyes. "If you believe Silas Vale's
name belongs in the witness box, then you know exactly what to do with the
ledger before I say another word."
> Yes, I think it begongs in the witness box
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> open the desk
Using the desk that way does nothing useful.
> open the steel cabinet
The keypad waits for a three-digit code you do not have yet.
> inventory
Inventory: empty.
> take the ledger
You cannot take the visitor ledger.
> inspect the desk
The desk is a cluttered fortress of incident forms and a dead flashlight, the
visitor ledger already open to the latest page as if waiting for an answer.
The ink on the recent entries glistens under the flickering light, demanding
that you look closer at who has been here.
> read the ledger
Inventory: empty.
> inspect the ledger
The ledger's final entry trembles under double red underlines, the ink stark
against the white page. You trace the name Silas Vale, knowing Mara's eyes will
follow the trail of that signature. The silence in the office feels heavier
now, waiting for the next clue to fall into place.
> help
Commands: inspect <object>, talk to Mara, use <item> on <target>, take <item>,
move <object>, inventory, look, help, quit.
> move ledger
You shift the visitor ledger, but it changes nothing useful.
> inspect the coat rack
Mara's raincoat drips onto the tiles, the metallic clink of a leather key clip
hanging empty from the sleeve seam. The rack remains barren, confirming that
whatever key belongs there is not on it. The silence of the office is broken
only by the rhythmic tapping of water against the floor.
> inspect the leather key clip
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> tak the key clip
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> take the key clip
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> inspect Mara's raincoat
Mara Voss watches your every move with controlled impatience, her eyes scanning
the room as if expecting a trap. She looks tired and suspicious, refusing to
volunteer the cabinet code despite your persistent inquiries. The silence in
the Security Office grows heavier with each passing second.
> inspect raincoat
The empty clip suggests the important key is stored elsewhere.
> move the coat rack
You shift the desk, but it changes nothing useful.
> move coat rack
You drag the coat rack aside, revealing only the slick sheen of wet tile and a
faint trail of grit beneath it. No spare key is hidden in the shadows of the
wood, and the silence of the office remains unbroken by the sound of brass or
distant sirens.
> move framed photo
You straighten the framed photo, revealing a pristine, dust-free rectangle behind
it that offers no hidden switch. The recent handling of the frame only deepens
the room's quiet theme: notice the details, do not expect tricks. The air in the
Security Office remains still, waiting for the next observation.
> talk to mara
"Careful with the coat rack, I've been testing to see if you'll notice the grit
trail beneath it. If you think I'm hiding something in the office, you should be looking at the visitor ledger instead."
> move visitor ledger
You shift the visitor ledger, but it changes nothing useful.
> take visitor ledger
You cannot take the visitor ledger.
> talk to Silas Vale
The ledger you just inspected was a dead end, Silas, but it confirmed that
someone else has been watching this room. If you truly want to know what I'm
hiding, you need to get out here and talk to the visitor in the corner, not keep
asking me.
> talk to the visitor
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> talk to mara
I know you want answers, Mara, but the visitor in the corner holds the truth I
cannot give you. Go inspect the ledger again; if that's a dead end, then someone
else is watching this room, and you're the only one who can see it.
> inspect the corner
That does not resolve into a safe action. Rephrase it with a clear object or
request.
> tell mara Silas Vale
Silas Vale is a man of many talents, yes, but his ledger is the only place his
true nature hides. Go back to the desk, open the ledger, and tell me what you
find there. If the pages are blank, then someone else is watching this room,
and you're the only one who can see it.
> open the ledger
Using the visitor ledger that way does nothing useful.
> inspect ledger
The ledger's final entry trembles under the red pencil, its double underlining
stark against the dim light. You recognize the name Silas Vale from the
visitor log, a detail Mara would likely dissect with sharp curiosity. The air
in the office feels heavy with the weight of a secret waiting to be uncovered.
> talk to mara
Silence is the only thing that keeps the shadows from shifting, so stop talking
and look at the ledger again. If you think you see something there, I will
believe you; if not, then someone else is already watching us.
> tell Mara I see something
The red pencil on the ledger is the only thing that matters right now, yet you
claim the steel cabinet holds a truth I cannot yet read. If that cabinet
contains more than a key, then the shadows are already shifting, and I am no
longer the only one watching us. Go back to the ledger; the answer to what
you see is written there, not in the cold steel.
> Silas Vale
That does not resolve into a safe action. Rephrase it with a clear object or
request.
Something is wrong with how the game decides that Mara should trust me. So the next step will be fixing this.