Tucano Proxy

Tucano Proxy is a free, MIT-licensed HTTP/HTTPS debugging proxy for developers who want to inspect traffic from a terminal, browser-based local interface, or desktop app. It is a strong fit for flexible capture and replay workflows; users who rely on breakpoints, response mocking, or interception of proxy-resistant clients should look elsewhere.

Overview

The project brings several interfaces to one configurable local proxy: a native CLI, terminal inspector, local web UI, and desktop app. The CLI, terminal UI, and web interface share persistent named sessions, and the CLI can run without a graphical session. That makes it practical to switch between terminal and desktop workflows without giving up session continuity.

Captures cover HTTP, HTTPS, and WebSocket traffic. The inspector combines request and response headers, timing, and bodies, with viewers for JSON, XML, HTML, raw text, hex, images, and forms. This breadth helps when debugging involves varied payloads, not just API responses.

Key features

Filtering, search, comparison, notes, and color marks help organize captures. Requests can be edited and replayed, then exported as cURL, HAR, or Python requests. These tools support reproducing a problem or carrying a request into another workflow. WebSocket inspection is supported, but breakpoint rules and response mocking are not; workflows that depend on pausing live traffic or simulating server replies will need another tool.

The project documents MCP integration and an installable coding-agent skill. From the CLI, users can open the web inspector in Maestri, Orca, or a system browser. These connections may suit developers incorporating traffic inspection into coding-agent workflows, while the core proxy remains useful without them.

Interception has practical limits: certificate pinning, application-specific trust stores, and clients that ignore proxy settings can prevent the proxy from seeing traffic. Tucano can create a root CA and offer OS trust-store installation, but ordinary startup does not install certificates or change system proxy settings. That explicit setup avoids silent network changes, though it means users must handle trust and proxy configuration deliberately.

The standalone service binds to loopback and requires authentication for inspection and mutations; its browser-facing API also validates Host and Origin. Documentation supports private capture and no-log compose, but built-in redaction does not reliably sanitize opaque binary bodies or guarantee anonymity. Users handling sensitive captures should not treat redaction as a substitute for checking payloads, and should not expose the service through a tunnel, reverse proxy, or public bind address.

Pricing

MIT License — free. The software is open source under the MIT license, with no paid tier or free trial. There are no paid-plan seat, quota, or renewal trade-offs to weigh. The project credits Paulo Cabral as creator and maintainer; no dedicated support terms are stated.

Platforms

Desktop installers are provided for macOS on Apple Silicon and Intel, and for Windows. Standalone CLI releases include macOS, Linux, and Windows targets; prebuilt Linux binaries target ARM64 and x64 with glibc. Alpine and other musl-based Linux systems are not among the prebuilt targets, so those users should verify a suitable route before adopting it. The CLI runs without a graphical session, while the web inspector is local.

Native CLI archives include SHA-256 checksums, and documented installers verify them before replacing the executable. The security guide notes that checksums are not independent publisher signatures, so they provide an integrity check rather than signed provenance.

Who it's for

Tucano suits developers who want a free, self-hostable proxy with terminal and desktop options, broad body viewers, replay, and export tools. It is especially appropriate when named sessions and a headless CLI matter. It is a weaker fit for teams that require breakpoints or response mocking, users on unsupported Linux binary targets, and debugging cases where the target app bypasses proxy settings or enforces certificate pinning.

Pros and cons

• Pros: HTTP, HTTPS, and WebSocket capture across CLI, terminal, web, and desktop interfaces gives developers several ways to work with the same sessions.
• Pros: Replay, comparison, notes, search, and exports to cURL, HAR, and Python requests support investigation as well as handoff.
• Pros: Loopback binding, authentication, and explicit certificate and proxy changes make local operation more deliberate.
• Cons: No breakpoint rules or response mocking leaves interactive interception and simulated replies to other tools.
• Cons: Certificate pinning, app-specific trust stores, and clients that ignore proxies can block capture.
• Cons: Prebuilt Linux CLI targets use glibc, not musl, and built-in redaction does not guarantee anonymity for opaque binary bodies.

Alternatives

Web Debugging Proxies is the broader category directory for comparing tools. Consider HTTP Toolkit if its free Hobbyist plan's manual request and response breakpoints and built-in HTTP client tools better match your workflow. Fluxzy is another option if you want a free Community Edition with all features included for personal use. Choose Moni Proxy if its free plan's mock, rewrite, and breakpoint rules or DNS overrides are more important than Tucano's cross-interface session workflow. Reqable may suit users who prefer a community plan with a stated one-device allowance and 100MB storage. mitmproxy is a free, open-source interactive HTTPS proxy to consider as another option. NetworkSpy, Probe, and Proxyfor are also alternatives to compare.

Verdict

Choose Tucano Proxy for a free, open-source debugging workflow that pairs varied capture viewers with replay, export, and terminal-to-desktop flexibility. Its local security posture and explicit setup suit developers who want control over proxy changes. Look elsewhere if breakpoints or response mocking are essential, or if your target client cannot be intercepted through a local proxy.