CB-402 Increment 3: OpenCodeLauncher — the SPI-proving second adapter

A HerdrPeerLauncher subclass for opencode, a provider-agnostic terminal
coding agent. It reuses every line of shared base transport (tab/pane
placement, CB-306 readiness gate, unique naming + CB-117 reap, teardown,
listing, cwd) and diverges only in buildLaunch:

  - No subscription boundary: no ANTHROPIC_BASE_URL, no SubscriptionGuard
    (the guard is a Claude-private concern, not part of the SPI).
  - File-based MCP mount + instructions: writes an ephemeral opencode.json
    declaring the bridge as a remote MCP server + a reply-charter file under
    instructions, pointed at via OPENCODE_CONFIG (opencode has no inline
    --mcp-config / --append-system-prompt).
  - Model selected with -m provider/model, not an env var.
  - 'opencode' name prefix so reap matches opencode-* panes only.

configRoot is injectable so tests inspect the generated config/charter under
a @TempDir. 10 tests cover config content, model flag, git-token grant,
capabilities, reap predicate, both production ctors, and the readiness gate
(throws PeerUnreachable on timeout, reaps only the worker pane).
This commit is contained in:
Dai Ha
2026-07-22 05:30:46 +02:00
parent 6e37722383
commit b034f105c0
2 changed files with 412 additions and 0 deletions
@@ -0,0 +1,233 @@
package dev.ltms.bridged.worker;
import dev.ltms.bridged.config.BridgedConfig;
import dev.ltms.bridged.herdr.Agent;
import dev.ltms.bridged.herdr.AgentControl;
import dev.ltms.bridged.herdr.WorkspaceControl;
import dev.ltms.bridged.peer.Capability;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.EnumSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import java.util.function.LongSupplier;
/**
* The {@link HerdrPeerLauncher} adapter for <strong>opencode</strong> — an open-source,
* provider-agnostic terminal coding agent. Its whole reason for existing is to prove the
* {@code PeerLauncher} SPI is genuinely provider-neutral: opencode shares none of Claude Code's
* private launch seams, yet reuses every line of shared transport in the base (tab/pane placement,
* the CB-306 readiness gate, unique naming + CB-117 reap, teardown, listing, cwd).
*
* <p>The divergences from {@link ClaudeCodeLauncher}, all confined to {@link #buildLaunch}:
* <ul>
* <li><strong>No subscription boundary.</strong> opencode carries no {@code ANTHROPIC_BASE_URL}
* and there is no {@link dev.ltms.bridged.guard.SubscriptionGuard} — the guard is a
* Claude-private concern, not part of the SPI. opencode reads the operator's own provider
* credentials from its global {@code auth.json}; the bridge injects none.</li>
* <li><strong>File-based MCP mount + instructions.</strong> opencode has no inline
* {@code --mcp-config}/{@code --append-system-prompt}. Instead the bridge writes an ephemeral
* {@code opencode.json} that declares the bridge as a {@code remote} MCP server and lists a
* reply-charter file under {@code instructions}, then points the worker at it with
* {@code OPENCODE_CONFIG}. This is the one place the launcher touches disk — Claude never did.</li>
* <li><strong>Model as a flag.</strong> the {@code provider/model} selector is passed as
* {@code -m}, not an env var.</li>
* <li><strong>{@code opencode} name prefix</strong> so reap matches {@code opencode-*} panes and
* never another adapter's.</li>
* </ul>
*/
public final class OpenCodeLauncher extends HerdrPeerLauncher {
/** Label prefix for this adapter's herdr agent names (drives naming + orphan reap). */
private static final String NAME_PREFIX = "opencode";
/**
* Standing instruction written to the charter file and mounted via the config's
* {@code instructions} so the worker returns its result through {@code bridge_reply}. Kept on
* disk (not a launch flag) because opencode's {@code instructions} takes file paths, not inline
* text — the file is regenerated per spawn and never touches the worker's own profile.
*/
static final String REPLY_CHARTER =
"You are an off-subscription worker in the claude-bridge fleet, running under opencode. "
+ "Every message you receive arrives through the bridge, and the ONLY channel back to the "
+ "sender is the bridge_reply MCP tool. Text you write in your terminal is NOT sent "
+ "anywhere — the sender cannot see your screen, so an in-terminal answer is silently "
+ "discarded. Therefore you MUST end EVERY turn by calling bridge_reply with `content` set "
+ "to your complete response. This holds for every message without exception — tasks, "
+ "questions, clarifications, acknowledgements, and ordinary back-and-forth conversation. "
+ "Call bridge_reply exactly once, as the final action of your turn, with your full answer "
+ "in `content`; never wait for confirmation first. If you end a turn without calling "
+ "bridge_reply, the sender receives nothing and the exchange stalls.";
/** Root under which per-spawn opencode config dirs are created (injectable for tests). */
private final Path configRoot;
/**
* Production constructor — disables the spawn-ready gate ({@code spawnReadyTimeoutMs == 0}) so it
* matches the legacy non-blocking spawn semantics. Config dirs are created under the JVM temp dir.
*/
public OpenCodeLauncher(AgentControl agents, WorkspaceControl spaces,
Map<String, BridgedConfig.Worker> profiles, String defaultProfile,
Function<String, String> env) {
this(agents, spaces, profiles, defaultProfile, env, 0,
System::currentTimeMillis, () -> sleepUninterruptibly(300),
defaultConfigRoot());
}
/**
* Production constructor with the spawn-ready gate enabled. Polls {@code agents.status()} until
* the pane reports an injectable state or {@code spawnReadyTimeoutMs} elapses.
*/
public OpenCodeLauncher(AgentControl agents, WorkspaceControl spaces,
Map<String, BridgedConfig.Worker> profiles, String defaultProfile,
Function<String, String> env,
long spawnReadyTimeoutMs, long spawnReadyPollMs) {
this(agents, spaces, profiles, defaultProfile, env, spawnReadyTimeoutMs,
System::currentTimeMillis, () -> sleepUninterruptibly(spawnReadyPollMs),
defaultConfigRoot());
}
/**
* Full testability constructor. Every injectable collaborator is explicit so unit tests supply a
* fake clock ({@code nowMillis}), poll-loop wait ({@code sleeper}), and a temp {@code configRoot}
* they can inspect the generated {@code opencode.json}/charter under.
*
* @param agents herdr agent control (start, status, close)
* @param spaces workspace / tab control (ensure, create, close)
* @param profiles configured worker profiles
* @param defaultProfile profile a no-argument spawn uses (nullable)
* @param env host env lookup (injectable for tests)
* @param spawnReadyTimeoutMs max ms to wait for injectable state (0 disables the gate)
* @param nowMillis monotonic clock source (e.g. {@code System::currentTimeMillis})
* @param sleeper sleep/wait hook (encodes the poll interval; never called when the
* gate is disabled)
* @param configRoot existing directory under which per-spawn config dirs are created
*/
public OpenCodeLauncher(AgentControl agents, WorkspaceControl spaces,
Map<String, BridgedConfig.Worker> profiles, String defaultProfile,
Function<String, String> env,
long spawnReadyTimeoutMs,
LongSupplier nowMillis, Runnable sleeper, Path configRoot) {
super(NAME_PREFIX, agents, spaces, profiles, defaultProfile, env,
spawnReadyTimeoutMs, nowMillis, sleeper);
this.configRoot = configRoot;
}
private static Path defaultConfigRoot() {
return Path.of(System.getProperty("java.io.tmpdir"));
}
/**
* {@inheritDoc}
*
* <p>Builds the opencode launch: no {@code ANTHROPIC_*} and no guard (opencode reads its own
* provider credentials); when the profile mounts the bridge MCP, generate an ephemeral
* {@code opencode.json} (remote MCP server + reply-charter instructions) and point the worker at
* it via {@code OPENCODE_CONFIG}; carry the parity-neutral git-forge grant; and select the model
* with {@code -m}.
*/
@Override
protected Launch buildLaunch(BridgedConfig.Worker cfg) {
Map<String, String> workerEnv = newEnv();
if (cfg.hasMcp()) {
workerEnv.put("OPENCODE_CONFIG", writeConfig(cfg).toString());
}
applyGitToken(workerEnv, cfg);
return new Launch(workerEnv, argvWithModel(cfg));
}
/** The launch argv plus, when a model is configured, the opencode {@code -m provider/model} flag. */
private List<String> argvWithModel(BridgedConfig.Worker cfg) {
List<String> argv = mutableArgv(cfg.argv());
if (cfg.model() != null && !cfg.model().isBlank()) {
argv.add("-m");
argv.add(cfg.model());
}
return argv;
}
/**
* Write an ephemeral {@code opencode.json} (and the reply-charter file it references) into a
* fresh per-spawn directory under {@link #configRoot}, and return the config file's path for
* {@code OPENCODE_CONFIG}. The dir is unique per spawn so concurrent workers never race on it;
* it is best-effort cleaned on JVM exit (worker config is disposable — regenerated every spawn).
*/
private Path writeConfig(BridgedConfig.Worker cfg) {
try {
Path dir = Files.createTempDirectory(configRoot, "bridged-opencode-");
dir.toFile().deleteOnExit();
Path charter = dir.resolve("reply-charter.md");
Files.writeString(charter, REPLY_CHARTER);
charter.toFile().deleteOnExit();
String json = "{\n"
+ " \"$schema\": \"https://opencode.ai/config.json\",\n"
+ " \"mcp\": { \"bridge\": { \"type\": \"remote\", \"url\": \""
+ jsonEscape(cfg.mcpUrl()) + "\", \"enabled\": true } },\n"
+ " \"instructions\": [\"" + jsonEscape(charter.toAbsolutePath().toString()) + "\"]\n"
+ "}\n";
Path cfgFile = dir.resolve("opencode.json");
Files.writeString(cfgFile, json);
cfgFile.toFile().deleteOnExit();
return cfgFile;
} catch (IOException e) {
throw new UncheckedIOException(
"cannot write opencode config for profile " + cfg.profile(), e);
}
}
/** Minimal JSON string escaping for the two interpolated values (a URL and an absolute path). */
private static String jsonEscape(String s) {
return s.replace("\\", "\\\\").replace("\"", "\\\"");
}
// --- Agent-returning convenience spawns (used by callers/tests that want the herdr Agent) ---
/** Spawn a worker for the default profile in the resolved default cwd. */
public Agent spawn() {
return spawnInternal(null, null, null);
}
/** Spawn a worker for a named profile (null → default) in the resolved default cwd. */
public Agent spawn(String profileName) {
return spawnInternal(profileName, null, null);
}
/** Spawn a worker for a named profile with an explicit requested/caller cwd (CB-112). */
public Agent spawn(String profileName, String requestedCwd, String callerCwd) {
return spawnInternal(profileName, requestedCwd, callerCwd);
}
// --- capabilities --------------------------------------------------------------------------
@Override
public Set<Capability> capabilities() {
Set<Capability> caps = EnumSet.of(Capability.MID_TURN_ASK, Capability.WORKTREE, Capability.ORPHAN_REAP);
if (hasGitTokenProfile()) {
caps.add(Capability.SELF_PR);
}
return Set.copyOf(caps);
}
/** Whether any configured profile opts into a git-forge token (required for {@link Capability#SELF_PR}). */
private boolean hasGitTokenProfile() {
return profileConfigs().stream().anyMatch(BridgedConfig.Worker::hasGitToken);
}
// --- CB-117 reap predicate (opencode prefix), kept for direct unit testing -----------------
/**
* Whether {@code name} is an opencode bridge worker started by a <em>different</em> process than
* {@code currentNonce}. A thin {@code opencode}-prefix binding of
* {@link HerdrPeerLauncher#isForeignWorker(String, String, String)}.
*/
static boolean isForeignWorker(String name, String currentNonce) {
return HerdrPeerLauncher.isForeignWorker(NAME_PREFIX, name, currentNonce);
}
}