---
library_name: transformers
tags:
- agent
license: llama3.1
language:
- en
base_model:
- meta-llama/Llama-3.1-8B
pipeline_tag: text-generation
---

# Telos Llama-3.1-8B (init)
 
A Llama-3.1-8B base model with eleven of its reserved special tokens
seeded with semantically related-content-token embeddings, in
preparation for fine-tuning on the [Telos](https://github.com/) agent
trajectory format.
 
This is **not a fine-tuned agent model.** It is the base model with
embedding initialization applied. Behavior on any task is identical
or near-identical to vanilla Llama-3.1-8B-base; the only difference is
that the eleven Telos reserved tokens now have non-zero embeddings in
both the input and output matrices.
 
## Model details
 
- **Base model:** `meta-llama/Llama-3.1-8B`
- **Modification:** in-place initialization of eleven reserved-token rows
  in `embed_tokens` and `lm_head`
- **Initialization method:** for each Telos marker, the mean of the
  input/output embeddings of 2-3 semantically related content tokens
- **Tokenizer:** unchanged from the base model
- **Vocabulary size:** unchanged (128 256)
## Token mapping
 
The Telos format aliases these eleven reserved tokens to frame markers
at the string level. The tokenizer in this repo is unchanged from the
base; aliasing is done by the Telos SDK at encode/decode time.
 
| Telos marker     | Reserved token                    | Token ID | Seed words                              |
| ---------------- | --------------------------------- | -------- | --------------------------------------- |
| `<\|goal\|>`       | `<\|reserved_special_token_0\|>`    | 128002   | goal, objective, purpose                |
| `<\|mission\|>`    | `<\|reserved_special_token_1\|>`    | 128003   | mission, task, instruction              |
| `<\|obs\|>`        | `<\|reserved_special_token_2\|>`    | 128005   | observation, context, environment       |
| `<\|belief\|>`     | `<\|reserved_special_token_3\|>`    | 128011   | belief, state, knowledge                |
| `<\|plan\|>`       | `<\|reserved_special_token_4\|>`    | 128012   | plan, strategy, approach                |
| `<\|think\|>`      | `<\|reserved_special_token_5\|>`    | 128013   | think, reasoning, thought               |
| `<\|action\|>`     | `<\|reserved_special_token_6\|>`    | 128014   | action, call, tool                      |
| `<\|end\|>`        | `<\|reserved_special_token_7\|>`    | 128015   | end, stop, done                         |
| `<\|result\|>`     | `<\|reserved_special_token_8\|>`    | 128016   | result, output, response                |
| `<\|feedback\|>`   | `<\|reserved_special_token_9\|>`    | 128017   | feedback, update, progress              |
| `<\|reward\|>`     | `<\|reserved_special_token_10\|>`   | 128018   | reward, score                           |
 
## Why initialization was needed
 
In the base Llama-3.1-8B model, all 250 reserved special tokens have
**all-zero embeddings** in both `embed_tokens` and `lm_head`. They were
registered as vocabulary entries but never received any pretraining
gradient.
 
For Telos, this is degenerate: the model cannot read the markers as
input (zero embedding contributes nothing) and cannot emit them as
output (zero `lm_head` row → near-zero logit → near-zero probability
after softmax). Empirically, prompting the base model with a
Telos-formatted trajectory causes the model to ignore the markers
entirely and loop on prose content.
 
Mean-of-related-tokens initialization seeds each marker with a sensible
starting representation. The model still does not understand the Telos
format - that requires fine-tuning - but the markers now contribute
meaningful signal to the forward pass and have non-zero output logits.
 
## Intended use
 
This checkpoint is intended as the starting point for fine-tuning on
Telos-formatted trajectories. Use it the same way you would use the
plain Llama-3.1-8B base.
 
```python
from transformers import AutoModelForCausalLM, AutoTokenizer
 
tokenizer = AutoTokenizer.from_pretrained("kosiasuzu/telos-llama-3.1-8b-init")
model = AutoModelForCausalLM.from_pretrained(
    "kosiasuzu/telos-llama-3.1-8b-init",
    torch_dtype="bfloat16",
    device_map="auto",
)
```
 
## Out-of-scope use
 
- **Not an agent yet.** This checkpoint has not been trained on any
  agent trajectories. Do not expect it to follow the Telos format
  correctly.
- **Not an instruction-tuned model.** It inherits all the base-model
  limitations of Llama-3.1-8B (looping on greedy decoding, no
  instruction following).
- All limitations and biases of Llama-3.1-8B base apply unchanged.
## License
 
Inherits the Llama 3.1 Community License from the base model. Use of
this model is subject to that license's terms.
 
## Citation
 
If you build on this, please cite the Telos project and the underlying
Llama-3.1 model.