agentwerk 0.1.9

A minimal Rust crate that gives any application agentic capabilities.
Documentation

Installation

cargo add agentwerk

Quick Start

use agentwerk::providers::{model_from_env, provider_from_env};
use agentwerk::tools::ReadFileTool;
use agentwerk::Agent;

#[tokio::main]
async fn main() {
    let results = Agent::new()
        .provider(provider_from_env().unwrap())
        .model(&model_from_env().unwrap())
        .role("You are a Rust developer who reads source files to answer questions.")
        .tool(ReadFileTool)
        .task("What does Cargo.toml describe?")
        .run_dry()
        .await;

    let answer = results.last().unwrap().result_string();
    println!("{answer}");
}

Use Cases

Example projects built with agentwerk:

Configure an LLM provider first (see Environment).

make use_case                # list available names
make use_case name=<name>    # run one

API

  • Agents: Workers that pick up tickets and produce results.
  • Prompting: Role, context, and task shaping the work of an agent.
  • Tickets: Ticket system allowing to orchestrate complex work.
  • Tools: Capabilities agents use to solve a ticket.
  • Knowledge: Knowledge base an agent creates during a run.
  • Schemas: Schemas for validating ticket results.
  • Events: Lifecycle events emitted while agents work.
  • Stats: Metrics about tickets, tokens and time.

Agents

An Agent picks up tickets, uses assigned tools to solve them, and writes the result back onto each ticket.

use agentwerk::tools::ReadFileTool;

let agent = Agent::new()
    .name("worker_0")
    .label("math")
    .tool(ReadFileTool)
Method Description
name(s) Set an identifier for assigning tickets.
label(l) / labels([..]) Restrict the agent to tickets carrying matching labels.
tool(t) / tools([..]) Register a tool the agent may call.
dir(p) Set the directory accessible for tool calls.

Providers

A Provider connects the agent to an LLM service. agentwerk ships providers for Anthropic, OpenAI, Mistral, and a LiteLLM proxy.

use agentwerk::providers::{AnthropicProvider, model_from_env, provider_from_env};

let agent = Agent::new()
    .provider(AnthropicProvider::new(key))
    .model("claude-sonnet-4-20250514");

// Or pick from environment variables (see Environment).
let agent = Agent::new()
    .provider(provider_from_env()?)
    .model(&model_from_env()?);

Each provider exposes .base_url(url) and .timeout(duration) to override the endpoint and request timeout.

Method Description
provider(p) Set the LLM provider.
model(m) Set the model the provider runs.

Prompting

Every prompt has three parts: role (who the agent is), context (the situation it operates in), and task (work it should perform). The structure follows the prompting guide.

let agent = Agent::new()
    .role("You are an arithmetic worker. Compute step by step and show your work.")
    .context("- Allowed operators: +, -, *, /\n- Output: write the final result on the last line.")
    .task("Compute (47 * 92) / 8, then round to the nearest integer.");

When context(...) is not set, agentwerk supplies a default block:

- Working directory: /Users/caro
- Platform: darwin
- OS version: 25.1.0
- Date: 2026-05-06
- Steps remaining: 8
- Input tokens remaining: 95000
- Output tokens remaining: 12000
- Time remaining: 240s

Tickets

The TicketSystem is the core data structure of agentwerk to orchestrate complex collaboration between agents. A task is the work itself, a ticket wraps it with additional metadata, like labels and schemas. Labels route work to matching agents.

use agentwerk::{Ticket, TicketSystem};

let tickets = TicketSystem::new();

tickets.agent(scout);
tickets.agent(analyst);

tickets.task_labeled("Scan src/ for unused imports.", "scan");

let report = Ticket::new("Categorise the findings by severity")
    .label("analyse")
    .schema(report_schema);

tickets.ticket(report);
Method Description
agent(agent) Register an agent with the system.
dir(d) Set the directory where knowledge, results, and ticket logs are persisted.
task(t) Submit a task.
task_labeled(t, l) Submit a task tagged with l for label-scoped routing.
task_schema(t, s) Submit a task whose result must validate against s.
task_schema_labeled(t, s, l) Submit a labeled task with a result schema.
ticket(t) Submit a caller-built Ticket.

Execution

Start executing tickets with run calls:

let running = tickets.run();              // returns immediately
let results = tickets.run_dry().await;    // waits for the queue to empty
Method Description
run() Begin processing tickets in the background. The caller can observe progress, submit more tickets, or stop the run while agents work.
run_dry().await Begin processing tickets and block until the queue is empty. Returns all collected TicketResults once agents stop.
interrupt_signal(s) Signal allowing to stop every agent and tool execution.

Policies

Configure execution policies on a ticket system. A breach fires EventKind::PolicyViolated and halts execution.

let tickets = TicketSystem::new()
    .max_steps(40)
    .max_time(std::time::Duration::from_secs(300))
    .max_input_tokens(200_000)
    .max_output_tokens(50_000)
    .max_request_tokens(8_000)
    .max_schema_retries(3)
    .max_request_retries(3)
    .request_retry_delay(std::time::Duration::from_millis(500));
Method Description
max_steps(n) Cap the total number of steps.
max_time(d) Cap the total elapsed duration.
max_input_tokens(n) Cap the total input tokens.
max_output_tokens(n) Cap the total output tokens.
max_request_tokens(n) Cap the input tokens per request.
max_schema_retries(n) Cap the schema-validation retry attempts.
max_request_retries(n) Cap the retry attempts on recoverable provider errors.
request_retry_delay(d) Set the base delay between request retries.

Tools

Give agents access to tools helping them to solve a given task. agentwerk provides minimal baseline tools:

Tool Description
File ReadFileTool Reads a file with line numbers, offset, and limit.
WriteFileTool Creates or overwrites a file.
EditFileTool Replaces text in a file.
Search GlobTool Finds files by pattern.
GrepTool Searches file contents.
ListDirectoryTool Lists files and directories.
Shell BashTool Runs shell commands matching an allowed pattern.
Web WebFetchTool Fetches a URL and returns its body.
Tickets WriteResultTool Writes the agent's result for the current ticket and marks it done.
ManageTicketsTool Reads the ticket queue and creates or edits tickets.
ReadTicketsTool Reads the ticket queue.
WriteTicketsTool Creates or edits tickets in the queue.
Knowledge KnowledgeTool Writes, reads, removes, or lists pages in the agent's knowledge store.
Discovery ToolSearchTool Discovers tools registered with Tool::defer(true).

Custom tools

Define custom tools for specific needs. Each tool declares a JSON-Schema for its inputs:

use agentwerk::{Tool, ToolResult};
use serde_json::json;

let greet = Tool::new("greet", "Say hello")
    .schema(json!({
        "type": "object",
        "properties": { "name": { "type": "string" } },
        "required": ["name"]
    }))
    .read_only(true)
    .handler(|input, _ctx| Box::pin(async move {
        let name = input["name"].as_str().unwrap_or("world");
        Ok(ToolResult::success(format!("Hello, {name}!")))
    }));

.read_only(true) allows the agent to run a tool concurrently with other read-only calls in the same step.

Knowledge

A Knowledge store is the agent's long-term memory. It is written to disk, can be shared across multiple agents, and is curated by the agent through KnowledgeTool.

use agentwerk::Knowledge;

// Override default knowledge path:
let agent = Agent::new().knowledge("./notes");

// Or share one store across multiple agents:
let store = Knowledge::open("./.agentwerk")?;
let alice = Agent::new().knowledge(&store);
let bob = Agent::new().knowledge(&store);
Method Description
knowledge(into) Set the knowledge store path.

Schemas

A Schema constrains the result an agent must produce for a ticket. A violation triggers a retry until max_schema_retries is exhausted.

use agentwerk::Schema;

let schema = Schema::parse(json!({
    "type": "object",
    "properties": { "title": { "type": "string" } },
    "required": ["title"]
}))?;

tickets.task_schema("Write a report.", schema);

Events

Events report everything that happens while your agents work and give you deep insights into behavior or failures.

use std::sync::Arc;
use agentwerk::{Event, EventKind};

let agent = Agent::new()
    .event_handler(Arc::new(|event: Event| {
        if let EventKind::TicketDone { key } = &event.kind {
            eprintln!("[{}] done {key}", event.agent_name);
        }
    }));
Kind Description
Ticket TicketStarted An agent claimed a ticket.
TicketDone A ticket finished successfully.
TicketFailed A ticket failed.
Provider RequestStarted A provider request started.
RequestFinished A provider request finished and reported its token usage.
RequestFailed A provider request failed and stopped the ticket.
TextChunkReceived A streamed text chunk arrived.
Tool ToolCallStarted A tool invocation started.
ToolCallFinished A tool invocation finished.
ToolCallFailed A tool invocation failed but the ticket continues.
Run PolicyViolated A policy limit was breached and execution stopped.

Stats

Stats contain metrics about the progress of your agents' work, allowing to optimize your agentic system and identify bottlenecks.

let s = tickets.stats();
let scan = s.stats_for_label("scan");
Method Description
Run run_duration() Return the run's elapsed duration, live while agents work and frozen once the loop finishes. None until the first ticket starts.
Work work_duration() Return the sum of every finished ticket's start-to-end span.
avg_work_duration() Return the mean of the same span, or None until a ticket finishes.
Tickets tickets_created() Return the count of tickets created.
tickets_done() Return the count of tickets that finished successfully.
tickets_failed() Return the count of tickets that failed.
tickets_success_rate() Return done / (done + failed), or None until a ticket finishes.
ticket_duration() Return the sum of every finished ticket's creation-to-end span.
avg_ticket_duration() Return the mean of the same span, or None until a ticket finishes.
Tokens input_tokens() Return the total input tokens across all provider responses.
output_tokens() Return the total output tokens across all provider responses.
Activity steps() Return the count of times an agent picked up a ticket to process.
requests() Return the total provider responses received.
tool_calls() Return the total tool calls.
errors() Return the total provider errors.
Labels stats_for_label(label) Return a nested Stats slice scoped to tickets carrying label.

Development

Workspace

  • crates/agentwerk/: the library.
  • crates/use-cases/: runnable example binaries that depend on the library.

Building and testing

make                # build (warnings are errors)
make test           # unit tests bundled by tests/unit (workspace --lib)
make fmt            # format code
make clean          # remove build artifacts
make update         # update dependencies

Integration tests

Configure an LLM provider first (see Environment).

make test_integration                     # run all
make test_integration name=bash_usage     # run one

Use cases

make use_case                                                 # list available
make use_case name=terminal-repl                              # run one
make use_case name=deep-research args="What is a good life?"  # with arguments

Publishing

make bump                  # bump patch version, run tests, commit, tag
make bump part=minor       # bump minor version
make bump part=major       # bump major version

GitHub Actions handles the crates.io publish via trusted publishing once the new tag is pushed (git push --tags).

Documentation

make doc                   # cargo doc --no-deps -p agentwerk (strict rustdoc)

LiteLLM proxy

Start a local LiteLLM proxy on port 4000 that forwards to a provider. Requires Docker.

make litellm                               # default: anthropic
make litellm LITELLM_PROVIDER=openai       # use OpenAI
make litellm LITELLM_PROVIDER=mistral      # use Mistral

Local inference servers

agentwerk relies on server-side tool calling. Enable it through the following flags:

Server Flag
vLLM --enable-auto-tool-choice --tool-call-parser <parser>
llama.cpp --jinja (enables tool calling)

Environment

Use cases and integration tests use the following environment variables:

General

Variable Description
MODEL Generic model override for model_from_env().
BRAVE_API_KEY Required by the deep-research example.

Anthropic

Variable Description
ANTHROPIC_API_KEY API key (required)
ANTHROPIC_BASE_URL API URL (default: https://api.anthropic.com)
ANTHROPIC_MODEL Model (default: claude-sonnet-4-20250514)

Mistral

Variable Description
MISTRAL_API_KEY API key (required)
MISTRAL_BASE_URL API URL (default: https://api.mistral.ai)
MISTRAL_MODEL Model (default: mistral-medium-2508)

OpenAI

Variable Description
OPENAI_API_KEY API key (required)
OPENAI_BASE_URL API URL (default: https://api.openai.com)
OPENAI_MODEL Model (default: gpt-4o)

LiteLLM proxy

Variable Description
LITELLM_BASE_URL Proxy URL (default: http://localhost:4000)
LITELLM_API_KEY Auth key (required to select via from_env())
LITELLM_MODEL Model (default: claude-sonnet-4-20250514)
LITELLM_PROVIDER LLM provider (anthropic, mistral, openai, litellm): explicit selection that overrides API-key auto-detection.