feat(codex): add codex app server adapter + e2e tests by joshsny · Pull Request #2975 · PostHog/code

joshsny · 2026-06-29T09:45:15Z

Adds app server implementation for codex adapter and e2e test coverage for the agent package

This is part 2 of 2 in a stack made with GitButler:

github-actions · 2026-06-29T09:45:44Z

React Doctor found 1 issue in 1 file · 1 warning.

1 warning

src/features/sessions/components/SteerQueueToggle.tsx

⚠️ src/features/sessions/components/SteerQueueToggle.tsx:19 Non-component export in component file only-export-components

_{Reviewed by React Doctor for commit 78af4dc.}

greptile-apps · 2026-06-29T09:55:35Z

_{Reviews (1): Last reviewed commit: "improve coverage of app server" | Re-trigger Greptile}

greptile-apps · 2026-06-29T09:55:38Z

+const ADAPTERS: Adapter[] = ["claude", "codex"];
+
+const EDIT_PROMPT =
+  "Do exactly these steps and nothing else: 1) Read the file target.txt. " +
+  "2) Edit it so the second line reads FOO instead of line2. " +
+  "3) Run the shell command `cat target.txt`. " +
+  "4) In one sentence confirm what you changed, then stop.";


for-loop over adapters instead of parametrised test

The for (const adapter of ADAPTERS) loop is a hand-rolled substitute for describe.each. The team's explicit rule is to prefer parametrised tests. The same pattern appears in structured-output.e2e.test.ts. Both files generate one describe block per adapter through a loop; describe.each expresses that intent directly and is idiomatic in Vitest.

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greptile-apps · 2026-06-29T09:55:39Z

+      { outcome: "selected", optionId: "option_1" },
+    ]);
+
+    const params = {
+      threadId: "t",
+      turnId: "turn",
+      itemId: "item-9",
+      autoResolutionMs: null,
+      questions: [
+        {
+          id: "q1",
+          header: "Pick one",
+          question: "Which environment?",
+          isOther: false,
+          isSecret: false,
+          options: [
+            { label: "staging", description: "" },
+            { label: "production", description: "danger" },
+          ],
+        },
+      ],
+    };
+
+    const result = await handleServerRequest(
+      APP_SERVER_REQUESTS.TOOL_USER_INPUT,
+      params,
+      client,
+      opts,
+    );
+
+    expect(result.handled).toBe(true);
+    expect(result.response).toEqual({
+      answers: { q1: { answers: ["production"] } },
+    });
+
+    // Prompt carried the question's options and the session id.
+    expect(calls).toHaveLength(1);
+    expect(calls[0].sessionId).toBe("sess-1");
+    expect(calls[0].options.map((o) => o.name)).toEqual([
+      "staging",
+      "production",
+    ]);
+  });
+
+  it("defaults a cancelled question to an empty answer", async () => {
+    const { client } = fakeClient([{ outcome: "cancelled" }]);
+
+    const params = {
+      threadId: "t",
+      turnId: "turn",
+      itemId: "item-1",
+      autoResolutionMs: null,
+      questions: [
+        {
+          id: "q1",
+          header: "h",
+          question: "q?",
+          isOther: false,
+          isSecret: false,
+          options: [{ label: "a", description: "" }],


Repetitive outcome tests could use it.each

The allow / reject / cancel outcome tests for each of the three request types (TOOL_USER_INPUT, PERMISSIONS_APPROVAL, MCP_ELICITATION) share the same structure: queue an outcome, call handleServerRequest, assert the response. Grouping them as it.each rows would express the same coverage more concisely, consistent with the team's preference for parametrised tests.

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Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

greptile-apps · 2026-06-29T09:55:40Z

+    if (block.type === "resource" && "text" in block.resource) {
+      const uri = block.resource.uri ?? "";
+      if (uri.startsWith("file://")) {
+        input.push(textInput(resourceLinkText(uri)));
+        continue;
+      }
+      input.push(textInput(uri));
+      context.push(
+        `<context ref="${uri}">\n${block.resource.text}\n</context>`,
+      );
+    }


Empty text block emitted when resource has no URI

When block.resource.uri is undefined or null, block.resource.uri ?? "" yields "" and textInput("") is pushed into the input array. Codex may reject a turn/start payload containing an empty-string text block, and the empty string carries no useful information — the resource content is already in the trailing <context ref=""> block. Skip the bare-URI push when uri is empty. This path has no unit test coverage.

Suggested change

if (block.type === "resource" && "text" in block.resource) {

const uri = block.resource.uri ?? "";

if (uri.startsWith("file://")) {

input.push(textInput(resourceLinkText(uri)));

continue;

}

input.push(textInput(uri));

context.push(

`<context ref="${uri}">\n${block.resource.text}\n</context>`,

);

}

if (block.type === "resource" && "text" in block.resource) {

const uri = block.resource.uri ?? "";

if (uri.startsWith("file://")) {

input.push(textInput(resourceLinkText(uri)));

continue;

}

if (uri) {

input.push(textInput(uri));

}

context.push(

`<context ref="${uri}">\n${block.resource.text}\n</context>`,

);

}

greptile-apps · 2026-07-01T18:04:44Z

_{Reviews (2): Last reviewed commit: "remove some comments" | Re-trigger Greptile}

greptile-apps · 2026-07-01T18:04:47Z

+        if (response.outcome.optionId === "reject_with_feedback") {
+          // codex's response has no feedback field, so decline and inject the guidance
+          // into the running turn (as its TUI does: Denied + a follow-up message).
+          const feedback = (response as { _meta?: { customInput?: unknown } })
+            ._meta?.customInput;
+          const activeTurnId = this.turns.activeTurnId;
+          if (typeof feedback === "string" && feedback.trim() && activeTurnId) {
+            void this.rpc
+              .request(APP_SERVER_METHODS.TURN_STEER, {
+                threadId: this.threadId,
+                input: toCodexInput([{ type: "text", text: feedback.trim() }]),
+                expectedTurnId: activeTurnId,
+              })
+              .catch((err) =>
+                this.logger.warn("turn/steer (reject feedback) failed", err),
+              );
+          }
+          return { decision: "decline" };


Stale activeTurnId after feedback steer

The reject_with_feedback path fires turn/steer as a fire-and-forget void call and never calls this.turns.onSteered(newTurnId) with the rotated turn ID that codex returns. After this steer completes, activeTurnId still points to the old (now invalid) turn ID. Any subsequent operation that reads activeTurnId — a second rejection with feedback, an interrupt, or a concurrent prompt() call that hits the turns.isRunning steer branch — will supply a stale expectedTurnId and codex will reject the request with a turn-ID mismatch error.

The main prompt() steer path shows the correct pattern: await the steer response, then call this.turns.onSteered(steerRes?.turnId) to keep the turn controller current.

joshsny mentioned this pull request Jun 29, 2026

feat(agent): Default Codex to the native app-server harness #2723

Draft

2 tasks

joshsny force-pushed the feat/codex-app-server-adapter branch from 00acd92 to 8899ff0 Compare June 29, 2026 09:47

joshsny force-pushed the codex/app-server-adapter-2 branch from c62e8b0 to 492b304 Compare June 29, 2026 09:47

joshsny marked this pull request as draft June 29, 2026 09:47

greptile-apps Bot reviewed Jun 29, 2026

View reviewed changes

joshsny requested a review from a team June 30, 2026 17:35

joshsny force-pushed the codex/app-server-adapter-2 branch 2 times, most recently from 14877aa to 7d28bad Compare July 1, 2026 18:00

joshsny marked this pull request as ready for review July 1, 2026 18:00

greptile-apps Bot reviewed Jul 1, 2026

View reviewed changes

joshsny added 13 commits July 2, 2026 12:20

improve coverage of app server

2b6cce7

add feature flag locally

1281368

add posthog meta for tool calling

054fbc5

add more e2e testing and fix some bugs

e06863a

cover execution mode bugs and testing

e166ee6

approvals

14b1281

add ci workflow, pull out app server agent

52b4484

compaction

dd7c551

more improvements

37b4513

include binary

0bbb9ba

don't relay background perm requests

98d1f70

remove some comments

d4256a5

resolve conflicts

78af4dc

joshsny force-pushed the feat/codex-app-server-adapter branch from 8899ff0 to 589557c Compare July 2, 2026 12:19

joshsny force-pushed the codex/app-server-adapter-2 branch from 7d28bad to 78af4dc Compare July 2, 2026 12:19

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feat(codex): add codex app server adapter + e2e tests#2975

feat(codex): add codex app server adapter + e2e tests#2975
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