diff --git a/.gitignore b/.gitignore
index 9dc547c9c..244d10d5b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ docker-compose.extra.yml
 dist
 *.bun-build
 pnpm-lock.yaml
+package-lock.json
 bun.lock
 bun.lockb
 coverage
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5909c9899..734dfd856 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Docs: https://docs.molt.bot
 Status: beta.
 
 ### Changes
+- Agents: add GitHub Copilot CLI (`copilot-cli`) as a built-in CLI backend for text-only fallback.
 - Rebrand: rename the npm package/CLI to `moltbot`, add a `moltbot` compatibility shim, and move extensions to the `@moltbot/*` scope.
 - Commands: group /help and /commands output with Telegram paging. (#2504) Thanks @hougangdev.
 - macOS: limit project-local `node_modules/.bin` PATH preference to debug builds (reduce PATH hijacking risk).
diff --git a/docs/docs.json b/docs/docs.json
index a463479aa..2870eac63 100644
--- a/docs/docs.json
+++ b/docs/docs.json
@@ -1008,6 +1008,8 @@
           "providers/models",
           "providers/openai",
           "providers/anthropic",
+          "providers/github-copilot",
+          "providers/github-copilot-cli",
           "bedrock",
           "providers/moonshot",
           "providers/minimax",
diff --git a/docs/gateway/cli-backends.md b/docs/gateway/cli-backends.md
index b80683a16..4db4556ce 100644
--- a/docs/gateway/cli-backends.md
+++ b/docs/gateway/cli-backends.md
@@ -32,6 +32,12 @@ Codex CLI also works out of the box:
 moltbot agent --message "hi" --model codex-cli/gpt-5.2-codex
 ```
 
+GitHub Copilot CLI works the same way (requires GitHub CLI auth):
+
+```bash
+moltbot agent --message "hi" --model copilot-cli/gpt-4.1
+```
+
 If your gateway runs under launchd/systemd and PATH is minimal, add just the
 command path:
 
@@ -200,6 +206,18 @@ Moltbot also ships a default for `codex-cli`:
 - `imageArg: "--image"`
 - `sessionMode: "existing"`
 
+Moltbot also ships a default for `copilot-cli`:
+
+- `command: "copilot"`
+- `args: ["-p"]`
+- `resumeArgs: ["-p", "--resume", "{sessionId}"]`
+- `output: "text"`
+- `modelArg: "--model"`
+- `sessionMode: "existing"`
+
+Note: Copilot CLI uses GitHub CLI (`gh`) for authentication and currently outputs
+text only (JSON output is not yet supported).
+
 Override only if needed (common: absolute `command` path).
 
 ## Limitations
diff --git a/docs/gateway/configuration.md b/docs/gateway/configuration.md
index 1d270974d..168fb549d 100644
--- a/docs/gateway/configuration.md
+++ b/docs/gateway/configuration.md
@@ -1668,6 +1668,9 @@ Example:
         "claude-cli": {
           command: "/opt/homebrew/bin/claude"
         },
+        "copilot-cli": {
+          command: "/opt/homebrew/bin/copilot"
+        },
         "my-cli": {
           command: "my-cli",
           args: ["--json"],
diff --git a/docs/providers/github-copilot-cli.md b/docs/providers/github-copilot-cli.md
new file mode 100644
index 000000000..34d975d85
--- /dev/null
+++ b/docs/providers/github-copilot-cli.md
@@ -0,0 +1,189 @@
+---
+summary: "Use GitHub Copilot CLI as a text-only fallback backend"
+read_when:
+  - You want to use GitHub Copilot CLI as a model provider
+  - You need a fallback when API providers fail
+  - You already have GitHub Copilot CLI installed
+---
+# GitHub Copilot CLI
+
+GitHub Copilot CLI (`copilot`) is GitHub's terminal-based AI assistant. Moltbot can use it as a
+**CLI backend** for text-only fallback when API providers are unavailable.
+
+## Prerequisites
+
+- **GitHub account** (free tier works for `gpt-4.1`)
+- **GitHub CLI** (`gh`) authenticated with your GitHub account
+
+Note: `gpt-4.1` is available on the free GitHub tier. Other models like `gpt-4o`, `claude-sonnet-4-5`,
+and `claude-opus-4-5` require a paid GitHub Copilot subscription.
+
+## Installation
+
+Install the Copilot CLI via npm:
+
+```bash
+npm install -g @github/copilot
+```
+
+Or via Homebrew:
+
+```bash
+brew install github/copilot/copilot
+```
+
+Verify installation:
+
+```bash
+copilot --help
+```
+
+## Quick start
+
+Use Copilot CLI directly with Moltbot:
+
+```bash
+moltbot agent --message "hi" --model copilot-cli/gpt-4.1
+```
+
+## Configuration
+
+### Minimal config (custom command path)
+
+If your gateway runs under launchd/systemd with a minimal PATH, specify the full path:
+
+```json5
+{
+  agents: {
+    defaults: {
+      cliBackends: {
+        "copilot-cli": {
+          command: "/opt/homebrew/bin/copilot"
+        }
+      }
+    }
+  }
+}
+```
+
+### Using as a fallback
+
+Add `copilot-cli` to your fallback list so it only runs when primary models fail:
+
+```json5
+{
+  agents: {
+    defaults: {
+      model: {
+        primary: "github-copilot/gpt-4.1",
+        fallbacks: [
+          "copilot-cli/gpt-4.1"
+        ]
+      },
+      models: {
+        "github-copilot/gpt-4.1": { alias: "Copilot" },
+        "copilot-cli/gpt-4.1": {}
+      }
+    }
+  }
+}
+```
+
+## Supported models
+
+Copilot CLI supports these models (availability depends on your GitHub plan):
+
+**Free tier (GitHub Free):**
+- `gpt-4.1` ← recommended default
+- `gpt-4.1-mini`
+
+**Paid tier (GitHub Copilot subscription):**
+- `gpt-4o`
+- `gpt-4-turbo`
+- `claude-sonnet-4-5`
+- `claude-opus-4-5`
+
+Example model refs:
+
+```
+copilot-cli/gpt-4.1
+copilot-cli/gpt-4.1-mini
+copilot-cli/gpt-4o
+copilot-cli/claude-sonnet-4-5
+```
+
+## Authentication
+
+Copilot CLI uses GitHub CLI authentication. Ensure you're logged in:
+
+```bash
+gh auth status
+```
+
+If not logged in:
+
+```bash
+gh auth login
+```
+
+## Limitations
+
+- **Text output only**: Copilot CLI does not support JSON output, so responses are plain text.
+- **Tools disabled**: CLI backends never receive tool calls. The CLI may still run its own agent tooling internally.
+- **No streaming**: CLI output is collected then returned.
+- **Session resume**: Uses `--resume` flag with session ID when available.
+
+## Differences from the API provider
+
+| Aspect | `github-copilot` (API) | `copilot-cli` (CLI backend) |
+|--------|------------------------|----------------------------|
+| Output format | JSON (structured) | Text only |
+| Tools | Moltbot tools work | Tools disabled |
+| Streaming | Supported | Not supported |
+| Auth | Device flow / token exchange | GitHub CLI (`gh auth`) |
+
+Choose the API provider (`github-copilot`) for full functionality. Use `copilot-cli` as a
+fallback when you want "always works" text responses.
+
+## Troubleshooting
+
+### CLI not found
+
+Set the full command path in your config:
+
+```json5
+{
+  agents: {
+    defaults: {
+      cliBackends: {
+        "copilot-cli": {
+          command: "/usr/local/bin/copilot"
+        }
+      }
+    }
+  }
+}
+```
+
+### Authentication errors
+
+Re-authenticate with GitHub CLI:
+
+```bash
+gh auth login
+gh auth status
+```
+
+### Model not available
+
+Model availability depends on your GitHub Copilot plan. Try a different model:
+
+```bash
+moltbot agent --message "hi" --model copilot-cli/gpt-4.1
+```
+
+## See also
+
+- [GitHub Copilot (API provider)](/providers/github-copilot)
+- [CLI backends](/gateway/cli-backends)
+- [Configuration](/gateway/configuration)
diff --git a/docs/providers/github-copilot.md b/docs/providers/github-copilot.md
index c7b68d1bd..c5e461f60 100644
--- a/docs/providers/github-copilot.md
+++ b/docs/providers/github-copilot.md
@@ -50,21 +50,21 @@ moltbot models auth login-github-copilot --yes
 ## Set a default model
 
 ```bash
-moltbot models set github-copilot/gpt-4o
+moltbot models set github-copilot/gpt-4.1
 ```
 
 ### Config snippet
 
 ```json5
 {
-  agents: { defaults: { model: { primary: "github-copilot/gpt-4o" } } }
+  agents: { defaults: { model: { primary: "github-copilot/gpt-4.1" } } }
 }
 ```
 
 ## Notes
 
 - Requires an interactive TTY; run it directly in a terminal.
-- Copilot model availability depends on your plan; if a model is rejected, try
-  another ID (for example `github-copilot/gpt-4.1`).
+- `gpt-4.1` is available on the free GitHub tier. Other models like `gpt-4o` and
+  Claude models require a paid GitHub Copilot subscription.
 - The login stores a GitHub token in the auth profile store and exchanges it for a
   Copilot API token when Moltbot runs.
diff --git a/docs/providers/index.md b/docs/providers/index.md
index c18ad70fb..914cde692 100644
--- a/docs/providers/index.md
+++ b/docs/providers/index.md
@@ -35,6 +35,7 @@ See [Venice AI](/providers/venice).
 
 - [OpenAI (API + Codex)](/providers/openai)
 - [Anthropic (API + Claude Code CLI)](/providers/anthropic)
+- [GitHub Copilot (API + CLI)](/providers/github-copilot)
 - [Qwen (OAuth)](/providers/qwen)
 - [OpenRouter](/providers/openrouter)
 - [Vercel AI Gateway](/providers/vercel-ai-gateway)
diff --git a/docs/testing.md b/docs/testing.md
index a990c4c23..d79fc8dd1 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -188,6 +188,7 @@ CLAWDBOT_LIVE_SETUP_TOKEN=1 CLAWDBOT_LIVE_SETUP_TOKEN_PROFILE=anthropic:setup-to
 - Overrides (optional):
   - `CLAWDBOT_LIVE_CLI_BACKEND_MODEL="claude-cli/claude-opus-4-5"`
   - `CLAWDBOT_LIVE_CLI_BACKEND_MODEL="codex-cli/gpt-5.2-codex"`
+  - `CLAWDBOT_LIVE_CLI_BACKEND_MODEL="copilot-cli/gpt-4.1"`
   - `CLAWDBOT_LIVE_CLI_BACKEND_COMMAND="/full/path/to/claude"`
   - `CLAWDBOT_LIVE_CLI_BACKEND_ARGS='["-p","--output-format","json","--permission-mode","bypassPermissions"]'`
   - `CLAWDBOT_LIVE_CLI_BACKEND_CLEAR_ENV='["ANTHROPIC_API_KEY","ANTHROPIC_API_KEY_OLD"]'`
@@ -205,6 +206,17 @@ CLAWDBOT_LIVE_CLI_BACKEND=1 \
   pnpm test:live src/gateway/gateway-cli-backend.live.test.ts
 ```
 
+### Copilot CLI
+
+```bash
+CLAWDBOT_LIVE_CLI_BACKEND=1 \
+  CLAWDBOT_LIVE_CLI_BACKEND_MODEL="copilot-cli/gpt-4.1" \
+  pnpm test:live src/gateway/gateway-cli-backend.live.test.ts
+```
+
+Note: Copilot CLI requires GitHub CLI auth (`gh auth status`). Output is text-only (no JSON).
+`gpt-4.1` is available on the GitHub Free tier; other models require a paid subscription.
+
 ### Recommended live recipes
 
 Narrow, explicit allowlists are fastest and least flaky:
diff --git a/src/agents/cli-backends.ts b/src/agents/cli-backends.ts
index 55344dedc..f448cf04b 100644
--- a/src/agents/cli-backends.ts
+++ b/src/agents/cli-backends.ts
@@ -25,6 +25,15 @@ const CLAUDE_MODEL_ALIASES: Record<string, string> = {
   "claude-haiku-3-5": "haiku",
 };
 
+const COPILOT_CLI_MODEL_ALIASES: Record<string, string> = {
+  "gpt-4o": "gpt-4o",
+  "gpt-4.1": "gpt-4.1",
+  "gpt-4.1-mini": "gpt-4.1-mini",
+  "gpt-4-turbo": "gpt-4-turbo",
+  "claude-sonnet-4-5": "claude-sonnet-4-5",
+  "claude-opus-4-5": "claude-opus-4-5",
+};
+
 const DEFAULT_CLAUDE_BACKEND: CliBackendConfig = {
   command: "claude",
   args: ["-p", "--output-format", "json", "--dangerously-skip-permissions"],
@@ -74,6 +83,20 @@ const DEFAULT_CODEX_BACKEND: CliBackendConfig = {
   serialize: true,
 };
 
+const DEFAULT_COPILOT_CLI_BACKEND: CliBackendConfig = {
+  command: "copilot",
+  args: ["--allow-all-tools"],
+  resumeArgs: ["--allow-all-tools", "--resume", "{sessionId}"],
+  output: "text",
+  input: "arg",
+  promptArg: "-p",
+  modelArg: "--model",
+  modelAliases: COPILOT_CLI_MODEL_ALIASES,
+  sessionIdFields: ["session_id", "sessionId"],
+  sessionMode: "existing",
+  serialize: true,
+};
+
 function normalizeBackendKey(key: string): string {
   return normalizeProviderId(key);
 }
@@ -107,6 +130,7 @@ export function resolveCliBackendIds(cfg?: MoltbotConfig): Set<string> {
   const ids = new Set<string>([
     normalizeBackendKey("claude-cli"),
     normalizeBackendKey("codex-cli"),
+    normalizeBackendKey("copilot-cli"),
   ]);
   const configured = cfg?.agents?.defaults?.cliBackends ?? {};
   for (const key of Object.keys(configured)) {
@@ -135,6 +159,12 @@ export function resolveCliBackendConfig(
     if (!command) return null;
     return { id: normalized, config: { ...merged, command } };
   }
+  if (normalized === "copilot-cli") {
+    const merged = mergeBackendConfig(DEFAULT_COPILOT_CLI_BACKEND, override);
+    const command = merged.command?.trim();
+    if (!command) return null;
+    return { id: normalized, config: { ...merged, command } };
+  }
 
   if (!override) return null;
   const command = override.command?.trim();
diff --git a/src/agents/cli-runner/helpers.ts b/src/agents/cli-runner/helpers.ts
index 833771a1f..23cd26968 100644
--- a/src/agents/cli-runner/helpers.ts
+++ b/src/agents/cli-runner/helpers.ts
@@ -445,7 +445,11 @@ export function buildCliArgs(params: {
     }
   }
   if (params.promptArg !== undefined) {
-    args.push(params.promptArg);
+    if (params.backend.promptArg) {
+      args.push(params.backend.promptArg, params.promptArg);
+    } else {
+      args.push(params.promptArg);
+    }
   }
   return args;
 }
diff --git a/src/agents/model-selection.ts b/src/agents/model-selection.ts
index 8d6db36de..d21c95db2 100644
--- a/src/agents/model-selection.ts
+++ b/src/agents/model-selection.ts
@@ -36,6 +36,7 @@ export function isCliProvider(provider: string, cfg?: MoltbotConfig): boolean {
   const normalized = normalizeProviderId(provider);
   if (normalized === "claude-cli") return true;
   if (normalized === "codex-cli") return true;
+  if (normalized === "copilot-cli") return true;
   const backends = cfg?.agents?.defaults?.cliBackends ?? {};
   return Object.keys(backends).some((key) => normalizeProviderId(key) === normalized);
 }
diff --git a/src/config/types.agent-defaults.ts b/src/config/types.agent-defaults.ts
index 9c6ce0211..45544926c 100644
--- a/src/config/types.agent-defaults.ts
+++ b/src/config/types.agent-defaults.ts
@@ -87,6 +87,8 @@ export type CliBackendConfig = {
   imageArg?: string;
   /** How to pass multiple images. */
   imageMode?: "repeat" | "list";
+  /** Flag used to pass the prompt (e.g. -p, --prompt). */
+  promptArg?: string;
   /** Serialize runs for this CLI. */
   serialize?: boolean;
 };
diff --git a/src/gateway/gateway-cli-backend.live.test.ts b/src/gateway/gateway-cli-backend.live.test.ts
index c39b34b91..baf64f4d1 100644
--- a/src/gateway/gateway-cli-backend.live.test.ts
+++ b/src/gateway/gateway-cli-backend.live.test.ts
@@ -29,6 +29,7 @@ const DEFAULT_CODEX_ARGS = [
   "read-only",
   "--skip-git-repo-check",
 ];
+const DEFAULT_COPILOT_CLI_ARGS = ["-p"];
 const DEFAULT_CLEAR_ENV = ["ANTHROPIC_API_KEY", "ANTHROPIC_API_KEY_OLD"];
 
 function randomImageProbeCode(len = 6): string {
@@ -216,7 +217,9 @@ describeLive("gateway live (cli backend)", () => {
         ? { command: "claude", args: DEFAULT_CLAUDE_ARGS }
         : providerId === "codex-cli"
           ? { command: "codex", args: DEFAULT_CODEX_ARGS }
-          : null;
+          : providerId === "copilot-cli"
+            ? { command: "copilot", args: DEFAULT_COPILOT_CLI_ARGS }
+            : null;
 
     const cliCommand = process.env.CLAWDBOT_LIVE_CLI_BACKEND_COMMAND ?? providerDefaults?.command;
     if (!cliCommand) {