Resterm

A terminal API client for REST, GraphQL, gRPC, WebSocket and SSE.

Resterm is a keyboard-driven API client that lives in your terminal and keeps everything local. It stores requests as plain files and supports SSH tunnels, Kubernetes port-forwarding, OAuth 2.0, and command-backed auth, with a fast feedback loop built around history, diffs, tracing, and profiling.

Quick links: Screenshots, Installation, Quick Start, Documentation.

Screenshot tour

Why Resterm

• HTTP, GraphQL, gRPC, WebSocket, and SSE are supported out of the box.
• Requests live in plain .http / .rest files.
• File-native automation - conditional logic (@when, @if/@elif/@else, @for-each), multi-step workflows (@workflow / @step), captures, variables and assertions (@capture, @var, @assert).
• RestermScript - a small, safe expression language purpose-built for Resterm.
• Vim-style TUI controls with familiar motions, / search and command-line actions like :w, :q, :q!, :wq, :x, :e, :help and :noh.
• OAuth 2.0 (client credentials, password, auth code + PKCE), command-backed auth via existing CLIs, SSH tunnels, and Kubernetes port-forwards are built in - no extra tools.
• CLI with resterm run for requests, workflows, JSON/JUnit output, and reusable run artifacts.
• Mock servers declared in the same files, with conditional scenarios, response interpolation, response sequences, hot reload, and response capture.
• Timeline tracing, profiling, and compare runs across environments.
• Streaming transcripts and an interactive console for WebSocket and SSE sessions.
• No cloud sync, no accounts, no telemetry. Everything stays local.
• There is no AI integration and there will never be.

CLI

Resterm also ships with built-in resterm run and resterm mock commands.

Use resterm run when you want to execute .http / .rest files directly from the terminal without opening the TUI.

Example:

mkdir my-api && cd my-api
resterm init
resterm run --request Echo requests.http

resterm init creates requests.http with sample requests and resterm.env.json with a dev environment that points at httpbin.org. The command above runs the Echo request which POSTs a JSON body and prints the response.

[!NOTE] This is different from the headless package. The headless package is the embeddable Go API for building your own runner or CI integration, while resterm run is the built-in CLI on top of the same execution engine.

See the full CLI documentation for usage, selectors, output formats, and examples.

Mock Servers

Resterm can serve mock responses straight from the same .http / .rest files your requests live in. Couple of highlights:

• Scenario matching per route: @match picks a response by query values, header rules (exact, prefix, present, absent) or a JSON body subset, and a default scenario answers everything else.
• Response sequences for polling and retry flows, with per-key cursors so every path, query, header, or cookie value advances through the sequence independently.
• Interpolated responses that echo request data like {{path.id}} or {{body.user.email}} and use generators like {{$uuid}}.
• Call count verification: declare # @expect calls=N next to a mock, then check it with resterm mock verify in CI or :mock verify in the TUI.
• Journal inspection from RestermScript: mock.count and mock.received let request assertions check what the mock server actually received.
• Hot reload and TLS support.

Two scenarios on one route look like this:

### Payment accepted
# @mock method=POST path=/payments name=accepted default=true latency=150ms
HTTP/1.1 202 Accepted
Content-Type: application/json

{"id":"pay_123","status":"pending"}

### Payment declined
# @mock method=POST path=/payments name=declined
# @match query={"mode":"decline"} headers={"X-Tenant":"demo"} json={"amount":0}
HTTP/1.1 422 Unprocessable Entity
Content-Type: application/json

{"error":"amount must be positive"}

Serve one file or a whole directory from the CLI:

resterm mock ./requests.http
resterm mock --recursive --addr 127.0.0.1:9090 ./requests
resterm mock verify ./requests.http

In the TUI, g Shift+M starts and stops the workspace server, :mock logs opens its request log, :mock reset [sequence] resets sequence cursors, and :mock verify checks active expectations. g a captures the focused live response as a mock block. Captured blocks stay unsaved on purpose so you can review headers and bodies for secrets before saving.

See the full Mock Servers reference, the resterm mock CLI guide, and the working example.

Headless

Resterm ships with the engine API, so you can build your own headless runner for Resterm and embed request execution in your own Go tooling/code, CI or internal automation.

The public Go API lives in the headless package and can run requests, workflows, assertions, compare runs and profiles without the TUI.

[!NOTE] If you don't want to build your own runner, check out resterm-runner.

Quick Start

1. Install Resterm (see Installation for install scripts, Windows, and manual installs).

   brew install resterm
   

2. Bootstrap a tiny workspace.

   mkdir my-api && cd my-api
   resterm init
   

3. Run it and send your first request.

   resterm
   

   Press Ctrl+Enter in the editor to send the highlighted request.

If you do not want files yet, just run resterm, type a URL in the editor, and press Ctrl+Enter. If you already have a curl command, paste it into the editor and press Ctrl+Enter to import it.

Navigation & layout cheat sheet

A few keys that make Resterm feel “native” quickly:

• Pane focus & layout

  • Tab / Shift+Tab - move focus between sidebar, editor, and response.
  • g+r - jump to Requests (sidebar).
  • g+i - jump to Editor.
  • g+p - jump to Response.
  • g+h / g+l - adjust layout:
    • When the left pane (sidebar) is focused: change sidebar width.
    • When editor/response are side-by-side: change editor/response width.
  • g+j / g+k - adjust layout:
    • When editor/response are stacked: change editor/response height.
    • When the navigator is focused: collapse/expand the selected branch.
  • g+v / g+s - toggle response pane between inline and stacked layout.
  • g+1, g+2, g+3 - minimize/restore sidebar, editor, response.
  • g+z / g+Z - zoom the focused pane / clear zoom.

• Environments & globals

  • Ctrl+E - switch environments.
  • Ctrl+G - inspect captured globals.

• Working with responses

  • Ctrl+V / Ctrl+U - split the response pane for side-by-side comparison.
  • When response pane is focused:
    • Ctrl+Shift+C or g y - copy the entire Pretty/Raw/Headers tab to the clipboard (no mouse selection needed).
  • g x - build an Explain preview for the active request without sending it.
  • g e - open the current or selected supported file in your external editor.

[!TIP] If you only remember three shortcuts…

• Ctrl+Enter - send request
• Tab / Shift+Tab - switch panes
• g+p - jump to response

Installation

Linux / macOS (Homebrew)

brew install resterm

[!NOTE] Homebrew installs should be updated with Homebrew (brew upgrade resterm). The built-in resterm --update command is for binaries installed from GitHub releases or install scripts.

Linux / macOS (Shell script)

[!IMPORTANT] Pre-built Linux binaries depend on glibc 2.32 or newer. If you run an older distro, build from source on a machine with a newer glibc toolchain or upgrade glibc before using the release archives.

curl -fsSL https://raw.githubusercontent.com/unkn0wn-root/resterm/main/install.sh | bash

or with wget:

wget -qO- https://raw.githubusercontent.com/unkn0wn-root/resterm/main/install.sh | bash

Windows (PowerShell)

iwr -useb https://raw.githubusercontent.com/unkn0wn-root/resterm/main/install.ps1 | iex

These scripts detect your architecture, download the latest release, and install the binary.

Manual installation

[!NOTE] The manual install helper uses curl and jq. Install jq with your package manager (brew install jq, sudo apt install jq, etc.).

Linux / macOS

# Detect latest tag
LATEST_TAG=$(curl -fsSL https://api.github.com/repos/unkn0wn-root/resterm/releases/latest | jq -r .tag_name)

# Download the matching binary (Darwin/Linux + amd64/arm64)
curl -fL -o resterm "https://github.com/unkn0wn-root/resterm/releases/download/${LATEST_TAG}/resterm_$(uname -s)_$(uname -m)"

# Make it executable and move it onto your PATH
chmod +x resterm
sudo install -m 0755 resterm /usr/local/bin/resterm

Windows (PowerShell)

$latest = Invoke-RestMethod https://api.github.com/repos/unkn0wn-root/resterm/releases/latest
$asset  = $latest.assets | Where-Object { $_.name -like 'resterm_Windows_*' } | Select-Object -First 1
Invoke-WebRequest -Uri $asset.browser_download_url -OutFile resterm.exe
# Optionally relocate to a directory on PATH, e.g.:
Move-Item resterm.exe "$env:USERPROFILE\bin\resterm.exe"

From source

go install github.com/unkn0wn-root/resterm/cmd/resterm@latest

Update

resterm --check-update
resterm --update

The first command reports whether a newer release is available. The second downloads, verifies and installs it in place. On Windows the previous binary is left beside the new one as resterm.exe.old. The next update replaces it once no process is still running the old version.

Quick Configuration Overview

• Environments are JSON files (resterm.env.json) discovered in the request directory, workspace root, or CWD. Dotenv files (.env, .env.*) are opt-in via --env-file and are single-workspace. Prefer JSON when you need multiple environments in one file.
• Config is stored per OS and can be overridden with RESTERM_CONFIG_DIR:
  • macOS: ~/Library/Application Support/resterm
  • Windows: %APPDATA%\resterm
  • Linux/Unix: ~/.config/resterm

Collections

Export a workspace into a Git-friendly Resterm bundle and import it into another workspace. Bundles carry a manifest.json with checksums so imports verify file integrity first, and environment values are replaced with REPLACE_ME placeholders on export so secrets stay out of the bundle.

resterm collection export --workspace ./my-api --out ./shared/my-api-bundle
resterm collection import --in ./shared/my-api-bundle --workspace ./my-local-api

Add --dry-run to preview an import and --force to overwrite existing files intentionally. Docs: docs/resterm.md#collection-sharing.

Inline curl import

Paste a curl command into the editor and press Ctrl+Enter to convert it into a structured request. Resterm understands common flags, merges repeated data segments, and keeps multipart uploads intact.

curl --compressed \
  --url "https://httpbin.org/post?source=resterm" \
  --request POST \
  -H "Accept: application/json" \
  --user resterm:test123 \
  -F file=@README.md

If you copied the command from a shell, prefixes like sudo or $ are ignored automatically.

RestermScript

RestermScript (RTS) is a small expression language built specifically for Resterm. Because it targets Resterm features directly, it can evolve alongside Resterm and stay symbiotic with the request format, workflows, and directives. JavaScript hooks are still available when you want them, but RTS is the default because it is readable, predictable, and focused on Resterm’s domain.

Quick example (RTS module + request):

// rts/helpers.rts
module helpers
export fn authHeader(token) {
  return token ? "Bearer " + token : ""
}

# @use ./rts/helpers.rts
# @when env.has("feature")
# @assert response.statusCode == 200
GET https://api.example.com/users/{{= vars.get("user") }}
Authorization: {{= helpers.authHeader(vars.get("auth.token")) }}

Full reference: docs/restermscript.md.

Deep dive

OAuth 2.0

Resterm supports client credentials, password grant, and authorization code + PKCE. For auth code flows, it opens your system browser, spins up a local callback server on 127.0.0.1, captures the redirect, and exchanges the code automatically. Tokens are cached per environment and refreshed when they expire. Docs: docs/resterm.md#oauth-20-directive and _examples/oauth2.http.

Workflows and scripting

Chain requests with @workflow and @step, pass data between steps, and add lightweight JS hooks where needed. Docs + sample: docs/resterm.md#workflows-multi-step-workflows and _examples/workflows.http.

Compare runs

Run the same request across environments with @compare or --compare, then diff responses side by side with g+c. Docs: docs/resterm.md#compare-runs.

Tracing and timeline

Add @trace with budgets to capture DNS, connect, TLS, TTFB, and transfer timings. Resterm visualizes overruns and can export spans to OpenTelemetry. Docs: docs/resterm.md#timeline--tracing.

Streaming (WebSocket and SSE)

Use @websocket with @ws steps or @sse to script and record streams. The Stream tab keeps transcripts and includes an interactive console. Docs: docs/resterm.md#streaming-sse--websocket.

gRPC

Resterm supports unary and streaming calls with transcripts, metadata, and body expansion for gRPC files. Docs: docs/resterm.md#grpc.

OpenAPI import

Convert OpenAPI 3 specs into Resterm .http collections from the CLI with --from-openapi, passing either a local file or an http(s) URL (e.g. --from-openapi https://api.example.com/openapi.json). Use --openapi-mode requests, mocks, or both to choose generated blocks. Remote fetches respect the global --insecure and --proxy flags. Docs: docs/cli.md#import-examples.

Curl import

Convert curl commands into .http files from the CLI with --from-curl. Docs: docs/resterm.md#importing-curl-commands.

SSH tunnels

Route HTTP, gRPC, WebSocket, and SSE traffic through bastions with @ssh profiles. Docs: docs/resterm.md#ssh-tunnels and _examples/ssh.http.

Kubernetes port-forwards

Route HTTP, gRPC, WebSocket, and SSE traffic through Kubernetes with @k8s profiles targeting pods/services/deployments/statefulsets. Docs: docs/resterm.md#kubernetes-port-forwards and _examples/k8s.http.

Theming and bindings

Customize colors and keybindings via themes/*.toml and bindings.toml or bindings.json under the config directory. Docs: docs/resterm.md#theming and docs/resterm.md#custom-bindings.

Documentation

• docs/resterm.md - the full reference: request syntax, directives, scripting and transports.
• docs/cli.md - the command-line guide: resterm run, importers, collections and history.