Terminal Agent

Build. Verify. Ship.
An autonomous terminal-based coding agent designed around verifiable software changes.

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Overview

Terminal Agent is an autonomous, terminal-first software engineering agent built by PicadoLabs.

Unlike conversational assistants that generate unverified code snippets or claim completion based on language model self-reporting, Terminal Agent enforces a Verify-First architectural paradigm. Every task follows a closed-loop engineering workflow:

OBSERVE  ->  PLAN  ->  ACT  ->  TEST  ->  INDEPENDENT VERIFY  ->  REPAIR  ->  PROVE COMPLETION

A task is only marked VERIFIED when an independent verification engine executes test suites inside an isolated sandbox, confirms contract assertions, and validates git diff boundaries.

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Why Terminal Agent?

Challenge with Standard AI Assistants	Terminal Agent Solution
Hallucinated Success: LLMs claim "all tests passed" without running them.	Independent Verifier: Dual-phase verification runs in a clean sandbox. The agent cannot verify itself.
Runaway Execution: Loops spin infinitely on difficult errors.	Bounded Agent Loop: Hard step limits, timeouts, and structured retry budgets.
Host System Risk: Unsafe commands (rm -rf, network calls) execute directly.	Multi-Tier Security & Sandboxing: Command classification (SAFE, WRITE, DESTRUCTIVE, NETWORK, PRIVILEGED), Docker / Local process-tree sandboxing, and real-time secret redaction.
Lost Progress on Failures: Bad edits break the repository state.	Automatic Checkpointing & Rollback: File snapshots and git branch isolation allow instant rollback to clean baselines.
Context Window Pollution: Large files blow LLM token limits.	Deterministic Context Ranker: BM25-based keyword and AST symbol relevance ranker fitting within strict token budgets.

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Key Features

• Verify-First Architecture: Explicit verification states (PENDING, VERIFIED, DONE, PARTIAL, FAILED, BLOCKED).
• Structured Task Contracts: Derives goals, allowed file scopes, invariant rules, and success criteria before writing code.
• 12 Core Engineering Tools: File inspection (read_file, list_files, search_files), atomic editing (write_file, edit_file), sandboxed execution (run_command, run_tests), git status/diff (git_status, git_diff, git_log), and checkpoint management (create_checkpoint, restore_checkpoint).
• 12-Category Failure Classifier & Self-Healing: Automatically categorizes errors (SYNTAX_ERROR, TEST_FAILURE, DEPENDENCY_ERROR, TIMEOUT, PERMISSION_ERROR, NETWORK_ERROR, CONTEXT_OVERFLOW, TOOL_ERROR, WRONG_SOLUTION, COMMAND_FAILURE, INCOMPLETE_TASK, UNKNOWN) and synthesizes targeted recovery plans.
• Dual Sandboxing Layer:
  • Local Sandbox: Subprocess isolation with psutil process-tree termination to prevent zombie child processes on timeout.
  • Docker Sandbox: Containerized execution with optional network isolation.
• Zero-Trust Secret Guard: Prevents reading or writing credentials (.env, *.pem, *.key, .ssh/*) and redacts API tokens from tool output streams.
• Model Agnostic: Supports local open models via Ollama (e.g., qwen2.5-coder, llama3), OpenAI, Anthropic Claude, Google Gemini, and a deterministic Mock Provider for CI testing.
• State Persistence & Resumption: SQLite database and mirrored JSON session history in .terminal_agent/ allowing instant session resumption (terminal-agent resume).

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System Architecture

flowchart TD
    CLI["Terminal Agent CLI<br/>terminal-agent run | resume | setup | doctor | status | diff | test"]
    
    CLI --> Loop["Core Agent Loop<br/>Observe -> Plan -> Act -> Test -> Verify -> Repair"]
    
    Loop --> Contract["Task Contract & Session Manager"]
    Loop --> Context["Context Engine (BM25 Deterministic Ranking)"]
    Loop --> Providers["Model Providers (Ollama, OpenAI, Claude, Gemini)"]
    
    Contract --> Registry["Tool Registry<br/>read_file | write_file | edit_file | run_command | run_tests | git_diff ..."]
    Context --> Registry
    Providers --> Registry
    
    Registry --> Security["Security Policy (Command Classifier & SecretGuard)"]
    Registry --> Sandbox["Execution Sandbox (Local psutil Process-Tree / Docker)"]
    
    Security --> Verifier["Independent Verification Engine<br/>Test runners, contract assertions, git diff boundaries"]
    Sandbox --> Verifier
    
    Verifier --> Recovery["12-Category Self-Healing Recovery Engine"]
    Recovery --> Loop

+-----------------------------------------------------------------------------------+
|                               TERMINAL AGENT CLI                                  |
|     terminal-agent [run | resume | setup | doctor | status | diff | test | trace]  |
+-----------------------------------------+-----------------------------------------+
                                          |
                                          v
+-----------------------------------------------------------------------------------+
|                                 CORE AGENT LOOP                                   |
|             Observe  --->  Plan  --->  Act  --->  Verify  --->  Repair            |
+--------------------+--------------------+--------------------+--------------------+
                     |                    |                    |
                     v                    v                    v
+--------------------------+ +--------------------------+ +-------------------------+
|     TASK CONTRACT &      | |      CONTEXT ENGINE      | |   MODEL PROVIDERS       |
|     SESSION MANAGER      | |  (Deterministic Ranking) | | (Ollama, OpenAI, Claude)|
+--------------------------+ +--------------------------+ +-------------------------+
                     |                    |                    |
                     v                    v                    v
+-----------------------------------------------------------------------------------+
|                                   TOOL REGISTRY                                   |
|      read_file | write_file | edit_file | run_command | run_tests | git_diff ...   |
+--------------------+--------------------+--------------------+--------------------+
                     |                    |
                     v                    v
+-----------------------------------------+ +---------------------------------------+
|             SECURITY POLICY             | |             SANDBOX                   |
|   (Command Classification, SecretGuard) | |   (psutil Local & Docker Containers)  |
+-----------------------------------------+ +---------------------------------------+
                     |
                     v
+-----------------------------------------------------------------------------------+
|                          INDEPENDENT VERIFICATION ENGINE                          |
|             (Test runners, contract assertions, git diff boundaries)              |
+-----------------------------------------+-----------------------------------------+
                                          |
                                          v
+-----------------------------------------------------------------------------------+
|                        12-CATEGORY RECOVERY & PROOF OF DONE                       |
+-----------------------------------------------------------------------------------+

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Installation

Prerequisites

• Python: 3.10, 3.11, or 3.12
• Git: 2.30+

Quick Onboarding Flow

# 1. Clone & install
git clone https://github.com/PicadoLabs/terminal-agent.git
cd terminal-agent
python -m venv .venv
source .venv/bin/activate  # On Windows: .venv\Scripts\Activate.ps1
pip install -e .

# 2. Configure model provider (Ollama or Cloud API)
terminal-agent setup

# 3. Verify environment health & ready providers
terminal-agent doctor

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Model Providers & Onboarding

Note: Ollama is OPTIONAL. You do not need Ollama installed if you use cloud providers (OpenAI, Anthropic Claude, or Google Gemini).

Terminal Agent automatically detects available model providers:

Option A: Interactive Setup (Recommended)

Run the guided interactive setup command:

terminal-agent setup

This command allows you to choose your provider, tests reachability, detects installed models, offers model pull confirmation for missing Ollama models, and safely configures keys.

Option B: Local Models via Ollama (Free, Private, No API Key)

1. Install Ollama (macOS, Linux, Windows).
2. Download a recommended coding model:

   ollama pull qwen2.5-coder
   

3. Terminal Agent will auto-detect your local Ollama instance without needing manual environment variables.

Option C: Cloud Providers via Environment Variables / .env

Set your API key via environment variables or a .env file (see .env.example):

# Anthropic Claude (e.g. claude-3-5-sonnet)
export ANTHROPIC_API_KEY="sk-ant-..."

# OpenAI (e.g. gpt-4o)
export OPENAI_API_KEY="sk-..."

# Google Gemini (e.g. gemini-1.5-pro)
export GEMINI_API_KEY="AIzaSy..."

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CLI Usage

Run terminal-agent inside any codebase or software repository:

1. Interactive Provider Setup

# Interactively configure Ollama, OpenAI, Claude, or Gemini
terminal-agent setup

2. Check System & Provider Health

# Inspect toolchains, sandbox, and provider readiness
terminal-agent doctor

3. Run an Autonomous Task

# Direct task execution using auto-resolved active provider
terminal-agent run "Fix the authentication token expiry bug and verify with pytest"

# Specify provider and model explicitly
terminal-agent run "Implement CSV streaming parser" --provider anthropic --model claude-3-5-sonnet-20241022

# Free local open model via Ollama
terminal-agent run "Refactor database connection pool" --provider ollama --model qwen2.5-coder

4. Interactive Mode

# Launch interactive terminal shell
terminal-agent

5. Workspace Status & Diff

# View active session status and step count
terminal-agent status

# View syntax-highlighted git diff of agent modifications
terminal-agent diff

6. Run Independent Verification

# Execute test suite through the verification engine
terminal-agent test

7. Checkpoints & Safe Rollback

# Create a named snapshot before experimental changes
terminal-agent checkpoint create --name "before_refactor"

# List all available checkpoints
terminal-agent checkpoint list

# Roll back workspace files to a specific checkpoint
terminal-agent rollback <CHECKPOINT_ID>

8. Resume Interrupted Sessions

# Resume execution from past state
terminal-agent resume <SESSION_ID>

9. View Execution Telemetry

# Print step trace, tool latency, and token metrics
terminal-agent trace <SESSION_ID>

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Configuration

Initialize or customize workspace configuration via terminal-agent.config.yaml:

terminal-agent config --init

Example terminal-agent.config.yaml:

agent:
  max_steps: 40
  max_retries: 3
  timeout_seconds: 600
  token_budget: 128000

sandbox:
  mode: local # or docker
  timeout_seconds: 60
  network: disabled # or enabled

verification:
  tests:
    - pytest
  assertions:
    - no_test_files_modified
    - api_contract_preserved
  diff:
    max_files_changed: 5
    allow_untracked_files: true
  auto_rollback_on_failure: false

security:
  network: disabled
  require_confirmation_for:
    - destructive
    - privileged
    - network

provider:
  name: ollama
  model: qwen2.5-coder

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Project Structure

terminal-agent/
├── benchmarks/                   # SWE evaluation benchmark suite
│   ├── tasks/                    # 10 diverse SWE benchmark tasks
│   └── runner.py                 # AgentBench-compatible evaluation harness
│
├── src/
│   └── terminal_agent/
│       ├── agent/                # Bounded autonomous loop orchestrator
│       ├── checkpoints/          # File snapshot and rollback manager
│       ├── cli/                  # CLI commands and Rich terminal UI
│       ├── config/               # Pydantic configuration schemas and settings
│       ├── context/              # BM25 ranker and repository context engine
│       ├── git/                  # Git adapter and working branch manager
│       ├── planner/              # Task contracts and execution planner
│       ├── providers/             # LLM adapters (Ollama, OpenAI, Claude, Gemini, Mock)
│       ├── recovery/              # Failure classifier and recovery engine
│       ├── sandbox/               # Local process and Docker sandbox runners
│       ├── security/              # Command classifier, secret guard, and policy enforcer
│       ├── session/               # SQLite and JSON state persistence
│       ├── telemetry/             # Event logging and performance metrics
│       ├── tools/                 # Typed engineering tools
│       └── verifier/              # Independent test runner and assertion engine
│
├── tests/
│   ├── e2e/                      # Full autonomous repair flow tests
│   ├── integration/              # Git, sandbox, and persistence tests
│   ├── unit/                     # Component unit tests
│   └── validation/               # Security, timeout, and runner validation tests
│
├── .github/
│   ├── ISSUE_TEMPLATE/
│   │   ├── bug_report.md
│   │   └── feature_request.md
│   ├── pull_request_template.md
│   └── workflows/
│       └── ci.yml
│
├── .env.example                  # Environment configuration template
├── .gitignore
├── pyproject.toml                # Package definition and build configuration
├── CONTRIBUTING.md               # Contribution guidelines
├── CODE_OF_CONDUCT.md            # Contributor Covenant code of conduct
├── SECURITY.md                   # Security policy and disclosure process
├── LICENSE                       # MIT License
└── README.md

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Development & Testing

Running Tests

# Run full automated test suite (47 tests)
pytest tests/ -v

Running the SWE Benchmark Suite

# Run 10-task evaluation benchmark
python -m benchmarks.runner

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Contributing

We welcome contributions from the community. Please review CONTRIBUTING.md for details on our workflow, coding standards, and pull request process.

Please also read our Code of Conduct.

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Security

Security is critical to Terminal Agent. If you discover a vulnerability, please report it privately by emailing picadolabs@gmail.com. For more information, see SECURITY.md.

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Community & Maintainers

Terminal Agent is maintained by PicadoLabs.

• GitHub Organization: https://github.com/PicadoLabs
• Website: https://picadolabs.me
• Contact & Inquiries: picadolabs@gmail.com

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License

This project is licensed under the MIT License - see the LICENSE file for details.

Copyright (c) 2026 PicadoLabs.