> ## Documentation Index > Fetch the complete documentation index at: https://unmute.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Unmute compiles to exactly three targets. Pipecat and LiveKit are code targets: compile writes a Python project you run. SLNG is a hosted target: compile writes a deployment body and SLNG runs the agent, so it has no `unmute dev`. Those three are the only values `provider` accepts in `targets.yaml`. Deepgram and ElevenLabs appear in these docs as model vendors, which is not the same thing as a target, and `slng` is both. > The Go structs in `internal/spec` and `internal/ir` are the schema truth. Check a field against them, or run `unmute validate`, rather than against what you remember. # Your first agent > The smallest real agent: a prompt, four models, and one file that says who is answering. An Unmute package is a directory. The agent lives in `agent.yaml`, the prompt lives in a Markdown file next to it, and the target choice lives in `targets.yaml`. This page walks that file, key by key. Everything else in this section adds to it. Make one now, then read along in the file it writes. Already ran this in the quickstart? You are sitting inside that `my-agent/` directory: `cd ..` first, or skip the command and read along in the file already on disk. ```sh theme={null} unmute init my-agent ``` ```text theme={null} created my-agent/agent.yaml created my-agent/.env.example created my-agent/.gitignore created my-agent/instructions.md created my-agent/targets.yaml created my-agent/tools/end_call.yaml ``` That package already validates and already runs. One agent, browser audio, one built-in tool so it can hang up, no phone number and no third-party account. Everything below is a tour of what is in it, so nothing here is a detour. On this page: * [The agent file](#the-agent-file) - every top-level key `unmute init` writes * [The target file](#the-target-file) - where this package compiles to * [Try it](#try-it) - validate, then talk to it in a browser ## The agent file The small snippets below keep one block on screen at a time. Expand the full file when you want to see how they fit together. This is `my-agent/agent.yaml` as the scaffold wrote it, with its explanatory comments taken out so the shape is visible. ```yaml theme={null} version: 1 name: my-agent entry_agent: assistant agents: assistant: instructions: instructions.md think: assistant_model speak: assistant_voice tools: - end_call secrets: - OPENAI_API_KEY - SLNG_API_KEY models: think: assistant_model: description: default reasoning model provider: openai model: "gpt-5.6-terra" params: reasoning_effort: none speak: assistant_voice: description: default voice provider: slng model: "deepgram/aura:2" voice: "aura-2-thalia-en" listen: transcriber: provider: slng model: "deepgram/nova:3" turn: detector: provider: livekit model: turn-detector-mini tools: - end_call conversation: greeting: speaks_first: agent text: "Hi there, I'm listening. What can I help you with?" channels: web: kind: realtime_audio capacity: peak_sessions: 10 max_sessions: 20 avg_session_duration: 5m ``` Now each block. ### `name` ```yaml theme={null} name: my-agent ``` What this agent is called. The deployed name is this joined to the target it was compiled for, so on a target called `livekit` it deploys as `my-agent-livekit`. Required, lowercase letters, digits and single hyphens, and it must not be a name another package in your organisation already uses: a deploy replaces the agent whose name it matches. The [`name` reference](/reference/agent-yaml#name) has the whole rule. ### `entry_agent` ```yaml theme={null} entry_agent: assistant ``` Which agent answers. A package can hold several agents; exactly one starts the call. The name has to be a key in the `agents:` map. ### `agents` ```yaml theme={null} agents: assistant: instructions: instructions.md think: assistant_model speak: assistant_voice ``` An agent is a prompt plus the models it speaks and thinks with. `instructions` is a path to a Markdown file in the package. Writing the prompt in its own file means it reviews like prose, not like YAML. ### `secrets` ```yaml theme={null} secrets: - OPENAI_API_KEY - SLNG_API_KEY ``` A list of environment variable names. Never values. Unmute writes these into the generated `.env.example` and into a startup check inside the generated project, so a missing key stops the container with a clear message instead of failing on the first spoken word. There is no way to write a secret's value in the package, on purpose. See [secrets](/reference/secrets). ### `models` Four kinds of model, grouped by what they do: | Section | Job | Common name | | -------- | --------------------------------------------- | --------------------- | | `think` | decides what to say and which tool to call | LLM | | `speak` | turns text into audio | TTS | | `listen` | turns audio into text | STT | | `turn` | decides when the caller has finished speaking | turn detection or VAD | Each section holds named entries. The name is yours: `assistant_model`, `assistant_voice`, `transcriber`, `detector` above. An agent then points at the entries it wants by name. ```yaml theme={null} models: think: assistant_model: provider: openai model: "gpt-5.6-terra" params: reasoning_effort: none ``` `provider` names the integration; `model` and `voice` are passed to that provider exactly as you wrote them. Unmute does not keep a list of valid model ids, so a typo shows up as a provider error at run time, not at compile time. `params:` is normally passthrough for anything else the provider takes. The one line here earns its place: `gpt-5.6-terra` is a reasoning model, and OpenAI refuses a chat request that carries function tools unless it sets `reasoning_effort`. This package has a tool, `end_call`, so the line is doing real work from the first run. The LiveKit Responses compiler directive is the narrow exception; [Reasoning model](/models/llm) has both forms. You can define more entries than you use. Unused entries are legal alternates, which makes swapping a voice a one line change. The `listen` and `turn` sections have one entry each here, so nothing needs to select them. With two or more entries you add a top level `listen:` or `turn:` line naming the one to use. ### `conversation` ```yaml theme={null} conversation: greeting: speaks_first: agent text: "Hi there, I'm listening. What can I help you with?" ``` Who speaks first and what they say. The greeting is spoken word for word without going through the model, so changing it changes nothing else. `conversation` also holds `interruption:`, `inactivity:` and `max_duration:`, which the scaffold leaves out; the [`conversation` reference](/reference/agent-yaml#conversation) has them. ### `channels` and `capacity` ```yaml theme={null} channels: web: kind: realtime_audio capacity: peak_sessions: 10 max_sessions: 20 avg_session_duration: 5m ``` `channels` says how people reach this agent. `web: realtime_audio` is browser audio, which is what `unmute dev` serves. Phones come later, in [Telephony](/telephony/overview). `capacity` is your traffic estimate. The compiler turns it into worker counts and quota numbers in the generated project, and marks them unbenchmarked because they come from a conservative assumption, not from a measurement of your agent. ## The target file ```yaml targets.yaml theme={null} targets: livekit: provider: livekit version: "1.8.1" sdk_language: python ``` One target. Nothing in `agent.yaml` names a target, so this file is the only place the choice lives, and one package can declare several. A second instance here compiles a second complete project from the same agent, and a target that cannot run a model entry as written overrides that entry by name rather than changing the agent. [Targets](/targets/overview) has both. ## Try it ```sh theme={null} unmute validate my-agent ``` The scaffolded package validates clean. A warning, when you do get one, does not stop the command: it names a real difference worth reading. Now talk to the agent in your browser: ```sh theme={null} unmute dev my-agent ``` ## Agent fields Path to a Markdown prompt inside the package. No prompt is inferred. Name of an entry in `models.think`. No profile is inferred. Name of an entry in `models.speak`. No profile is inferred. Names of loaded tool files this agent may call. Omit for no ordinary tools. Nested task definitions or bare names of tasks defined by another agent. Omit for no tasks. See [task fields](/build/orchestration/tasks#every-key-a-task-takes). Names from the top-level `task_groups` catalog. Omit for no groups. Names from the top-level `handoffs` catalog. Omit for no agent handoffs. Names from the top-level `escalations` catalog. Omit for no human transfers. ## Where to go next One rule that gets you from this agent to several. Personalize each call and pass values without exposing them to the model. Every supported `agent.yaml` key and value.