GitHub Copilot CLI SDK for Rust

A Rust SDK for programmatic access to the GitHub Copilot CLI.

Note: This SDK is in technical preview and may change in breaking ways.

See github/copilot-sdk for the equivalent SDKs in TypeScript, Python, Go, and .NET. The Rust SDK seeks parity with those SDKs; see Differences From Other SDKs below for the small set of intentional divergences.

Quick Start

use std::sync::Arc;
use github_copilot_sdk::{Client, ClientOptions, SessionConfig};
use github_copilot_sdk::handler::ApproveAllHandler;

# async fn example() -> Result<(), github_copilot_sdk::Error> {
let client = Client::start(ClientOptions::default()).await?;
let session = client.create_session(
    SessionConfig::default().with_handler(Arc::new(ApproveAllHandler)),
).await?;
let _message_id = session.send("Hello!").await?;
session.disconnect().await?;
client.stop().await.ok();
# Ok(())
# }

Architecture

Your Application
       ↓
  github_copilot_sdk::Client  (manages CLI process lifecycle)
       ↓
  github_copilot_sdk::Session (per-session event loop + handler dispatch)
       ↓ JSON-RPC over stdio or TCP
  copilot --server --stdio

The SDK manages the CLI process lifecycle: spawning, health-checking, and graceful shutdown. Communication uses JSON-RPC 2.0 over stdin/stdout with Content-Length framing (the same protocol used by LSP). TCP transport is also supported.

API Reference

Client

// Start a client (spawns CLI process)
let client = Client::start(options).await?;

// Create a new session
let session = client.create_session(config.with_handler(handler)).await?;

// Resume an existing session
let session = client.resume_session(config.with_handler(handler)).await?;

// Low-level RPC
let result = client.call("method.name", Some(params)).await?;
let response = client.send_request("method.name", Some(params)).await?;

// Health check (echoes message back, returns typed PingResponse)
let pong = client.ping("hello").await?;

// Shutdown
client.stop().await?;

ClientOptions:

Field	Type	Description
program	CliProgram	Resolve (default: auto-detect) or Path(PathBuf) (explicit)
prefix_args	Vec<OsString>	Args before --server (e.g. script path for node)
cwd	PathBuf	Working directory for CLI process
env	Vec<(OsString, OsString)>	Environment variables for CLI process
env_remove	Vec<OsString>	Environment variables to remove
extra_args	Vec<String>	Extra CLI flags
transport	Transport	Stdio (default), Tcp { port }, or External { host, port }

With the default CliProgram::Resolve, Client::start() automatically resolves the binary via github_copilot_sdk::resolve::copilot_binary() — checking COPILOT_CLI_PATH, the embedded CLI, and then the system PATH. Use CliProgram::Path(path) to skip resolution.

Session

Created via Client::create_session or Client::resume_session. Owns an internal event loop that dispatches events to the SessionHandler.

use github_copilot_sdk::MessageOptions;

// Simple send — &str / String convert into MessageOptions automatically.
// Returns the assigned message ID for correlation with later events.
let _id = session.send("Fix the bug in auth.rs").await?;

// Send with mode and attachments
let _id = session
    .send(
        MessageOptions::new("What's in this image?")
            .with_mode("autopilot")
            .with_attachments(attachments),
    )
    .await?;

// Message history
let messages = session.get_messages().await?;

// Abort the current agent turn
session.abort().await?;

// Model management
let model = session.get_model().await?;
session.set_model("claude-sonnet-4.5", None).await?;

// Mode management (interactive, plan, autopilot)
let mode = session.get_mode().await?;
session.set_mode("autopilot").await?;

// Workspace files
let files = session.list_workspace_files().await?;
let content = session.read_workspace_file("plan.md").await?;

// Plan management
let (exists, content) = session.read_plan().await?;
session.update_plan("Updated plan content").await?;

// Fleet (sub-agents)
session.start_fleet(Some("Implement the auth module")).await?;

// Cleanup (preserves on-disk session state for later resume)
session.disconnect().await?;

Typed RPC namespace

The ergonomic helpers above are convenience wrappers over a fully-typed JSON-RPC namespace generated from the GitHub Copilot CLI schema. Client::rpc() and Session::rpc() give direct access to every method on the wire, including ones with no helper today, with strongly-typed request and response structs.

// Methods with helpers — wire strings live in one generated place.
let files = session.rpc().workspaces().list_files().await?.files;
let models = client.rpc().models().list().await?.models;

// Methods with no helper — full schema-typed access.
let agents = session.rpc().agent().list().await?.agents;
let tasks = session.rpc().tasks().list().await?.tasks;
let forked = client
    .rpc()
    .sessions()
    .fork(github_copilot_sdk::generated::api_types::SessionsForkRequest {
        session_id: "session-id".to_string(),
        from_message_id: None,
    })
    .await?;

New RPCs land in the namespace immediately as the schema regenerates; helpers are added on top only when an ergonomic story is worth the maintenance.

SessionHandler

Implement this trait to control how a session responds to CLI events. Two styles are supported:

1. Per-event methods (recommended). Override only the callbacks you care about; every method has a safe default (permission → deny, user input → none, external tool → "no handler", elicitation → cancel, exit plan → default). This is the serenity::EventHandler pattern.

use async_trait::async_trait;
use github_copilot_sdk::handler::{PermissionResult, SessionHandler};
use github_copilot_sdk::types::{PermissionRequestData, RequestId, SessionId};

struct MyHandler;

#[async_trait]
impl SessionHandler for MyHandler {
    async fn on_permission_request(
        &self,
        _sid: SessionId,
        _rid: RequestId,
        data: PermissionRequestData,
    ) -> PermissionResult {
        if data.extra.get("tool").and_then(|v| v.as_str()) == Some("view") {
            PermissionResult::Approved
        } else {
            PermissionResult::Denied
        }
    }

    async fn on_session_event(&self, sid: SessionId, event: github_copilot_sdk::types::SessionEvent) {
        println!("[{sid}] {}", event.event_type);
    }
}

2. Single on_event method. Override on_event directly and match on HandlerEvent — useful for logging middleware, custom routing, or when you want one exhaustive dispatch point.

use github_copilot_sdk::handler::*;
use async_trait::async_trait;

#[async_trait]
impl SessionHandler for MyRouter {
    async fn on_event(&self, event: HandlerEvent) -> HandlerResponse {
        match event {
            HandlerEvent::SessionEvent { session_id, event } => {
                println!("[{session_id}] {}", event.event_type);
                HandlerResponse::Ok
            }
            HandlerEvent::PermissionRequest { .. } => {
                HandlerResponse::Permission(PermissionResult::Approved)
            }
            HandlerEvent::UserInput { question, .. } => {
                HandlerResponse::UserInput(Some(UserInputResponse {
                    answer: prompt_user(&question),
                    was_freeform: true,
                }))
            }
            _ => HandlerResponse::Ok,
        }
    }
}

The default on_event dispatches to the per-event methods, so overriding on_event short-circuits them entirely — pick one style per handler.

Events are processed serially per session — blocking in a handler method pauses that session's event loop (which is correct, since the CLI is also waiting for the response). Other sessions are unaffected.

Note: Notification-triggered events (PermissionRequest via permission.requested, ExternalTool via external_tool.requested) are dispatched on spawned tasks and may run concurrently with the serial event loop. See the trait-level docs on SessionHandler for details.

SessionConfig

let config = SessionConfig {
    model: Some("gpt-5".into()),
    system_message: Some(SystemMessageConfig {
        content: Some("Always explain your reasoning.".into()),
        ..Default::default()
    }),
    request_elicitation: Some(true),    // enable elicitation provider
    ..Default::default()
};
let session = client.create_session(config.with_handler(handler)).await?;

Session Hooks

Hooks intercept CLI behavior at lifecycle points — tool use, prompt submission, session start/end, and errors. Install a SessionHooks impl with [SessionConfig::with_hooks] — the SDK auto-enables hooks in SessionConfig when one is set.

use std::sync::Arc;
use github_copilot_sdk::hooks::*;
use async_trait::async_trait;

struct MyHooks;

#[async_trait]
impl SessionHooks for MyHooks {
    async fn on_hook(&self, event: HookEvent) -> HookOutput {
        match event {
            HookEvent::PreToolUse { input, ctx } => {
                if input.tool_name == "dangerous_tool" {
                    HookOutput::PreToolUse(PreToolUseOutput {
                        permission_decision: Some("deny".to_string()),
                        permission_decision_reason: Some("blocked by policy".to_string()),
                        ..Default::default()
                    })
                } else {
                    HookOutput::None // pass through
                }
            }
            HookEvent::SessionStart { input, .. } => {
                HookOutput::SessionStart(SessionStartOutput {
                    additional_context: Some("Extra system context".to_string()),
                    ..Default::default()
                })
            }
            _ => HookOutput::None,
        }
    }
}

let session = client
    .create_session(
        config
            .with_handler(handler)
            .with_hooks(Arc::new(MyHooks)),
    )
    .await?;

Hook events: PreToolUse, PostToolUse, UserPromptSubmitted, SessionStart, SessionEnd, ErrorOccurred. Each carries typed input/output structs. Return HookOutput::None for events you don't handle.

System Message Transforms

Transforms customize system message sections during session creation. The SDK injects action: "transform" entries for each section ID your transform handles.

use github_copilot_sdk::transforms::*;
use async_trait::async_trait;

struct MyTransform;

#[async_trait]
impl SystemMessageTransform for MyTransform {
    fn section_ids(&self) -> Vec<String> {
        vec!["instructions".to_string()]
    }

    async fn transform_section(
        &self,
        _section_id: &str,
        content: &str,
        _ctx: TransformContext,
    ) -> Option<String> {
        Some(format!("{content}\n\nAlways be concise."))
    }
}

let session = client
    .create_session(
        config
            .with_handler(handler)
            .with_transform(Arc::new(MyTransform)),
    )
    .await?;

Tool Registration

Define client-side tools as named types with ToolHandler, then route them with ToolHandlerRouter. Enable the derive feature for schema_for::<T>() — it generates JSON Schema from Rust types via schemars.

use std::sync::Arc;
use github_copilot_sdk::handler::ApproveAllHandler;
use github_copilot_sdk::tool::{
    schema_for, tool_parameters, JsonSchema, ToolHandler, ToolHandlerRouter,
};
use github_copilot_sdk::{Error, SessionConfig, Tool, ToolInvocation, ToolResult};
use serde::Deserialize;
use async_trait::async_trait;

#[derive(Deserialize, JsonSchema)]
struct GetWeatherParams {
    /// City name
    city: String,
    /// Temperature unit
    unit: Option<String>,
}

struct GetWeatherTool;

#[async_trait]
impl ToolHandler for GetWeatherTool {
    fn tool(&self) -> Tool {
        Tool {
            name: "get_weather".to_string(),
            namespaced_name: None,
            description: "Get weather for a city".to_string(),
            parameters: tool_parameters(schema_for::<GetWeatherParams>()),
            instructions: None,
        }
    }

    async fn call(&self, inv: ToolInvocation) -> Result<ToolResult, Error> {
        let params: GetWeatherParams = serde_json::from_value(inv.arguments)?;
        Ok(ToolResult::Text(format!("Weather in {}: sunny", params.city)))
    }
}

// Build a router that dispatches tool calls by name
let router = ToolHandlerRouter::new(
    vec![Box::new(GetWeatherTool)],
    Arc::new(ApproveAllHandler),
);

let config = SessionConfig {
    tools: Some(router.tools()),
    ..Default::default()
}
.with_handler(Arc::new(router));
let session = client.create_session(config).await?;

Tools are named types (not closures) — visible in stack traces and navigable via "go to definition". The router implements SessionHandler, forwarding unrecognized tools and non-tool events to the inner handler.

For trivial tools that don't need a named type, define_tool collapses the definition to a single expression:

use github_copilot_sdk::tool::{define_tool, JsonSchema, ToolHandlerRouter};
use github_copilot_sdk::ToolResult;
use serde::Deserialize;

#[derive(Deserialize, JsonSchema)]
struct GetWeatherParams { city: String }

let router = ToolHandlerRouter::new(
    vec![define_tool(
        "get_weather",
        "Get weather for a city",
        |_inv, params: GetWeatherParams| async move {
            Ok(ToolResult::Text(format!("Sunny in {}", params.city)))
        },
    )],
    Arc::new(ApproveAllHandler),
);

The closure receives the full ToolInvocation alongside the deserialized parameters, so handlers that need inv.session_id or inv.tool_call_id for telemetry, streaming updates, or scoped lookups can use them directly. Use _inv when you don't need the metadata.

Reach for the ToolHandler trait directly when you need shared state across multiple methods or want a named type that shows up by name in stack traces.

Permission Policies

Set a permission policy directly on SessionConfig with the chainable builders. They wrap whatever handler you've installed (defaulting to DenyAllHandler if none) so only permission requests are intercepted; every other event flows through unchanged.

let session = client
    .create_session(
        SessionConfig::default()
            .with_handler(Arc::new(my_handler))
            .approve_all_permissions(),
        // or .deny_all_permissions()
        // or .approve_permissions_if(|data| {
        //     data.extra.get("tool").and_then(|v| v.as_str()) != Some("shell")
        // })
    )
    .await?;

Call the policy method after with_handler — with_handler overwrites the handler field, so approve_all_permissions().with_handler(...) discards the wrap.

For composing a policy onto a handler outside the builder chain (e.g. when wrapping a ToolHandlerRouter you've built elsewhere), the permission module exposes the same primitives as free functions:

use github_copilot_sdk::permission;

let router = ToolHandlerRouter::new(tools, Arc::new(MyHandler));
let handler = permission::approve_all(Arc::new(router));
// or permission::deny_all(...) / permission::approve_if(..., predicate)

let session = client.create_session(config.with_handler(handler)).await?;

Capabilities & Elicitation

The SDK negotiates capabilities with the CLI after session creation. Enable elicitation to let the agent present structured UI dialogs (forms, URL prompts) to the user.

let config = SessionConfig {
    request_elicitation: Some(true),
    ..Default::default()
};

The handler receives HandlerEvent::ElicitationRequest with a message, optional JSON Schema for form fields, and an optional mode. Known modes include Form and Url, but the mode may be absent or an unknown future value. Return HandlerResponse::Elicitation(result).

User Input Requests

Some sessions ask the user free-form questions (or multiple-choice prompts) outside the elicitation flow. Implement SessionHandler::on_user_input and the SDK will forward userInput.request callbacks:

async fn on_user_input(
    &self,
    _session_id: SessionId,
    question: String,
    choices: Option<Vec<String>>,
    _allow_freeform: Option<bool>,
) -> Option<UserInputResponse> {
    // Render `question` + `choices` to your UI, then:
    Some(UserInputResponse {
        answer: "Yes".to_string(),
        was_freeform: false,
    })
}

Return None to signal "no answer available" (the CLI falls back to its own prompt). Enable via SessionConfig::request_user_input (defaults to Some(true)).

Slash Commands

Register named commands so users can invoke them as /name args from the TUI:

use github_copilot_sdk::types::{CommandContext, CommandDefinition, CommandHandler};
use async_trait::async_trait;

struct DeployCommand;

#[async_trait]
impl CommandHandler for DeployCommand {
    async fn on_command(&self, ctx: CommandContext) -> Result<(), github_copilot_sdk::Error> {
        println!("deploy {}", ctx.args);
        Ok(())
    }
}

let mut config = SessionConfig::default();
config.commands = Some(vec![
    CommandDefinition::new("deploy", Arc::new(DeployCommand))
        .with_description("Deploy the application"),
]);

Only name and description are sent over the wire; the handler stays in your process. Returning Err(_) surfaces the message back through the TUI.

Streaming

Set streaming: true to receive incremental delta events alongside finalized messages:

let mut config = SessionConfig::default();
config.streaming = Some(true);

let mut events = session.subscribe();
while let Ok(event) = events.recv().await {
    match event.event_type.as_str() {
        "assistant.message_delta" | "assistant.reasoning_delta" => {
            if let Some(d) = event.data.get("delta").and_then(|v| v.as_str()) {
                print!("{d}");
            }
        }
        "assistant.message" => println!(),  // final
        _ => {}
    }
}

When streaming is off (the default), only the final assistant.message and assistant.reasoning events fire. Delta events arrive in order; concatenating their delta text payloads reproduces the final message.

Infinite Sessions

Enable the SDK's session-store integration so conversations persist across CLI restarts and grow beyond the model's context window via automatic compaction:

use github_copilot_sdk::types::InfiniteSessionConfig;

let mut infinite = InfiniteSessionConfig::default();
infinite.workspace_path = Some("/path/to/workspace".into());

let mut config = SessionConfig::default();
config.infinite_sessions = Some(infinite);

The CLI emits session.compaction_start / session.compaction_complete events around each compaction. The session id remains stable across compactions; resume with Client::resume_session to pick up a prior conversation. Workspace state lives under ~/.copilot/session-state/{sessionId} by default — override with workspace_path to relocate.

Custom Providers (BYOK)

Route model traffic through your own inference endpoint instead of GitHub's hosted models:

use github_copilot_sdk::types::ProviderConfig;

let mut provider = ProviderConfig::default();
provider.provider_type = Some("openai".to_string());
provider.base_url = "https://my-proxy.example.com/v1".to_string();
provider.bearer_token = Some(std::env::var("OPENAI_API_KEY")?);

let mut config = SessionConfig::default();
config.provider = Some(provider);

Provider types include "openai", "azure", and "anthropic". Set wire_api to "completions" or "responses" (OpenAI/Azure only). Custom headers go in provider.headers. The SDK forwards the configuration to the CLI verbatim — the CLI handles the upstream call, including authentication.

Telemetry

Forward OpenTelemetry signals from the spawned CLI process to your collector:

use github_copilot_sdk::{ClientOptions, OtelExporterType, TelemetryConfig};

let mut telem = TelemetryConfig::default();
telem.exporter_type = Some(OtelExporterType::OtlpHttp);
telem.otlp_endpoint = Some("http://localhost:4318".to_string());
telem.source_name = Some("my-app".to_string());

let mut opts = ClientOptions::default();
opts.telemetry = Some(telem);
let client = Client::start(opts).await?;

The SDK injects the appropriate environment variables (COPILOT_OTEL_EXPORTER_TYPE, OTEL_EXPORTER_OTLP_ENDPOINT, ...) into the spawned CLI process. The SDK takes no OpenTelemetry dependency; the CLI itself owns the exporter pipeline. Caller-supplied ClientOptions::env entries override telemetry-injected values.

Progress Reporting (send_and_wait)

For fire-and-forget messaging where you need to block until the agent finishes:

use std::time::Duration;
use github_copilot_sdk::MessageOptions;

// Sends a message and blocks until session.idle or session.error
session
    .send_and_wait(
        MessageOptions::new("Fix the bug").with_wait_timeout(Duration::from_secs(120)),
    )
    .await?;

Default timeout is 60 seconds. Only one send_and_wait can be active per session — concurrent calls return an error.

Newtypes

SessionId — a newtype wrapper around String that prevents accidentally passing workspace IDs or request IDs where session IDs are expected. Transparent serialization (#[serde(transparent)]), zero-cost Deref<Target=str>, and ergonomic comparisons with &str and String.

use github_copilot_sdk::SessionId;

let id = SessionId::new("sess-abc123");
assert_eq!(id, "sess-abc123");           // compare with &str
let raw: String = id.into_inner();       // unwrap when needed

Error Handling

The SDK uses a typed error enum:

pub enum Error {
    Protocol(ProtocolError),       // JSON-RPC framing, CLI startup, version mismatch
    Rpc { code: i32, message: String }, // CLI returned an error response
    Session(SessionError),         // Session not found, agent error, timeout, conflicts
    Io(std::io::Error),            // Transport I/O error
    Json(serde_json::Error),       // Serialization error
    BinaryNotFound { name, hint }, // CLI binary not found
}

// Check if the transport is broken (caller should discard the client)
if err.is_transport_failure() {
    client = Client::start(options).await?;
}

Differences From Other SDKs

The Rust SDK aligns closely with the Node, Python, and Go SDKs but diverges in a few places where Rust idiom or the type system gives a clearly better shape, and exposes a small additional surface where the language affords ergonomics the dynamically-typed SDKs don't.

Shape divergence

• SessionFsProvider registration is direct, not factory-closure. Where Node/Python/Go accept a closure that the runtime calls on each session-create to build a fresh provider, the Rust SDK takes Arc<dyn SessionFsProvider> directly via [SessionConfig::with_session_fs_provider]. The factory pattern doesn't cleanly express in Rust at the session-config call site — there is no Session value to thread in, and the SDK already prefers traits over boxed closures for handler-shaped APIs (SessionHandler, SessionHooks, ToolHandler).

use std::sync::Arc;
use github_copilot_sdk::session_fs::{SessionFsConfig, SessionFsConventions};

let mut options = ClientOptions::default();
options.session_fs = Some(SessionFsConfig::new(
    "/workspace",
    "/workspace/.copilot",
    SessionFsConventions::Posix,
));
let client = Client::start(options).await?;

let session = client
    .create_session(
        SessionConfig::default()
            .with_handler(Arc::new(ApproveAllHandler))
            .with_session_fs_provider(Arc::new(MyProvider::new())),
    )
    .await?;

See examples/session_fs.rs for a complete in-memory provider implementation.

Rust-only API

A handful of conveniences exist only on the Rust SDK as of 0.1.0. These are surface areas where Rust idiom (newtypes, enums, trait objects) gives a clearly nicer shape than Node/Python/Go currently expose. Rust gets to be Rust here — cross-SDK parity for these is a post-release conversation, not a release blocker. None of these are deprecated and none of them are scheduled for removal.

• Typed newtypes — SessionId and RequestId are #[serde(transparent)] newtypes around String, so the type system distinguishes a session identifier from an arbitrary String at compile time. Node/Python/Go use bare strings.
• Permission policy builders — permission::approve_all, permission::deny_all, and permission::approve_if(handler, predicate) in crate::permission provide composable, no-handler-needed permission shortcuts that wrap an existing SessionHandler. Other SDKs require a full handler implementation for these patterns.
• Client::from_streams — connect to a CLI server over arbitrary caller-supplied AsyncRead / AsyncWrite. Useful for testing, in-process embedding, or custom transports. Other SDKs are spawn-only or fixed-stdio.
• enum Transport { Stdio, Tcp, External } — explicit, exhaustive transport selector on ClientOptions::transport. Node/Python/Go rely on conditional config field combinations instead.
• Split prefix_args / extra_args on ClientOptions — separate arg vectors for "prepend before subcommand" vs "append after the built-in flags", giving precise control over CLI invocation order without string-splicing.
• SessionHandler::on_auto_mode_switch — typed handler for the CLI's rate-limit-recovery prompt (CLI's autoModeSwitch.request callback, added in copilot-agent-runtime PR #7024). Returns AutoModeSwitchResponse::{Yes, YesAlways, No}. Default impl declines. Cross-SDK parity is post-release follow-up — Node / Python / Go / .NET consumers currently observe the request as a raw event and must drive the wire response themselves.

Layout

File	Description
lib.rs	Client, ClientOptions, CliProgram, Transport, Error
session.rs	Session struct, event loop, send/send_and_wait, Client::create_session/resume_session
subscription.rs	EventSubscription / LifecycleSubscription (Stream-able observer handles for subscribe() / subscribe_lifecycle())
handler.rs	SessionHandler trait, HandlerEvent/HandlerResponse enums, ApproveAllHandler
hooks.rs	SessionHooks trait, HookEvent/HookOutput enums, typed hook inputs/outputs
transforms.rs	SystemMessageTransform trait, section-level system message customization
tool.rs	ToolHandler trait, ToolHandlerRouter, schema_for::<T>() (with derive feature)
types.rs	CLI protocol types (SessionId, SessionEvent, SessionConfig, Tool, etc.)
resolve.rs	Binary resolution (copilot_binary, node_binary, extended_path)
embeddedcli.rs	Embedded CLI extraction (embedded-cli feature)
router.rs	Internal per-session event demux
jsonrpc.rs	Internal Content-Length framed JSON-RPC transport

Embedded CLI

By default, copilot_binary() searches COPILOT_CLI_PATH, the system PATH, and common install locations. To ship with a specific CLI version embedded in the binary, set COPILOT_CLI_VERSION at build time:

COPILOT_CLI_VERSION=1.0.15 cargo build

How it works

1. Build time: The SDK's build.rs detects COPILOT_CLI_VERSION, downloads the platform-appropriate archive from the github/copilot-cli GitHub Releases (copilot-{platform}.tar.gz on macOS/Linux, .zip on Windows), verifies the archive's SHA-256 against the release's SHA256SUMS.txt, extracts the copilot binary, compresses it with zstd, and embeds via include_bytes!(). No extra steps or tools needed — just the env var.

2. Runtime: On the first call to github_copilot_sdk::resolve::copilot_binary(), the embedded binary is lazily extracted to ~/.cache/github-copilot-sdk-{version}/copilot (or copilot.exe on Windows), SHA-256 verified, and cached. Subsequent calls return the cached path.

3. Dev builds: Without the env var, build.rs does nothing. The binary is resolved from PATH as usual — zero friction.

Resolution priority

copilot_binary() checks these sources in order:

1. COPILOT_CLI_PATH environment variable
2. Embedded CLI (build-time, via COPILOT_CLI_VERSION)
3. System PATH + common install locations

Platforms

Supported: darwin-arm64, darwin-x64, linux-x64, linux-arm64, win32-x64, win32-arm64. The target platform is auto-detected from CARGO_CFG_TARGET_OS and CARGO_CFG_TARGET_ARCH (cross-compilation works).

Features

No features are enabled by default — the bare SDK resolves the CLI from COPILOT_CLI_PATH or the system PATH without pulling in additional feature-gated dependencies.

Feature	Default	Description
embedded-cli	—	Build-time CLI embedding via COPILOT_CLI_VERSION (adds sha2, zstd). Enable when you need to ship a self-contained binary with a pinned CLI version.
derive	—	schema_for::<T>() for generating JSON Schema from Rust types (adds schemars). Enable when defining tool parameters.

# These examples use registry syntax for illustration; until the crate is
# published, use a path or git dependency instead.

# Minimal — resolve CLI from PATH
github-copilot-sdk = "0.1"

# Ship a pinned CLI version in your binary
github-copilot-sdk = { version = "0.1", features = ["embedded-cli"] }

# Derive JSON Schema for tool parameters
github-copilot-sdk = { version = "0.1", features = ["derive"] }

# Both
github-copilot-sdk = { version = "0.1", features = ["embedded-cli", "derive"] }