chore: consolidate model utils and drive-by cleanups (#476)

Signed-off-by: Thibault Sottiaux <tibo@openai.com>

codex-cli/src/approvals.ts

@@ -136,8 +136,8 @@ export function canAutoApprove(
     // bashCmd could be a mix of strings and operators, e.g.:
     //   "ls || (true && pwd)" => [ 'ls', { op: '||' }, '(', 'true', { op: '&&' }, 'pwd', ')' ]
     // We try to ensure that *every* command segment is deemed safe and that
-    // all operators belong to an allow‑list. If so, the entire expression is
+    // all operators belong to an allow-list. If so, the entire expression is
-    // considered auto‑approvable.
+    // considered auto-approvable.
 
     const shellSafe = isEntireShellExpressionSafe(bashCmd);
     if (shellSafe != null) {
@@ -333,7 +333,7 @@ export function isSafeCommand(
       };
     case "true":
       return {
-        reason: "No‑op (true)",
+        reason: "No-op (true)",
         group: "Utility",
       };
     case "echo":
@@ -442,10 +442,10 @@ function isValidSedNArg(arg: string | undefined): boolean {
 
 // ---------------- Helper utilities for complex shell expressions -----------------
 
-// A conservative allow‑list of bash operators that do not, on their own, cause
+// A conservative allow-list of bash operators that do not, on their own, cause
 // side effects. Redirections (>, >>, <, etc.) and command substitution `$()`
 // are intentionally excluded. Parentheses used for grouping are treated as
-// strings by `shell‑quote`, so we do not add them here. Reference:
+// strings by `shell-quote`, so we do not add them here. Reference:
 // https://github.com/substack/node-shell-quote#parsecmd-opts
 const SAFE_SHELL_OPERATORS: ReadonlySet<string> = new Set([
   "&&", // logical AND
@@ -471,7 +471,7 @@ function isEntireShellExpressionSafe(
   }
 
   try {
-    // Collect command segments delimited by operators. `shell‑quote` represents
+    // Collect command segments delimited by operators. `shell-quote` represents
     // subshell grouping parentheses as literal strings "(" and ")"; treat them
     // as unsafe to keep the logic simple (since subshells could introduce
     // unexpected scope changes).
@@ -539,7 +539,7 @@ function isParseEntryWithOp(
   return (
     typeof entry === "object" &&
     entry != null &&
-    // Using the safe `in` operator keeps the check property‑safe even when
+    // Using the safe `in` operator keeps the check property-safe even when
     // `entry` is a `string`.
     "op" in entry &&
     typeof (entry as { op?: unknown }).op === "string"

codex-cli/src/cli.tsx

@@ -136,7 +136,7 @@ const cli = meow(
       },
       noProjectDoc: {
         type: "boolean",
-        description: "Disable automatic inclusion of project‑level codex.md",
+        description: "Disable automatic inclusion of project-level codex.md",
       },
       projectDoc: {
         type: "string",
@@ -202,19 +202,20 @@ complete -c codex -a '(_fish_complete_path)' -d 'file path'`,
   console.log(script);
   process.exit(0);
 }
-// Show help if requested
+
+// For --help, show help and exit.
 if (cli.flags.help) {
   cli.showHelp();
 }
 
-// Handle config flag: open instructions file in editor and exit
+// For --config, open custom instructions file in editor and exit.
 if (cli.flags.config) {
-  // Ensure configuration and instructions file exist
   try {
-    loadConfig();
+    loadConfig(); // Ensures the file is created if it doesn't already exit.
   } catch {
     // ignore errors
   }
+
   const filePath = INSTRUCTIONS_FILEPATH;
   const editor =
     process.env["EDITOR"] || (process.platform === "win32" ? "notepad" : "vi");
@@ -237,13 +238,13 @@ let config = loadConfig(undefined, undefined, {
 const prompt = cli.input[0];
 const model = cli.flags.model ?? config.model;
 const imagePaths = cli.flags.image;
-const provider = cli.flags.provider ?? config.provider;
+const provider = cli.flags.provider ?? config.provider ?? "openai";
 const apiKey = getApiKey(provider);
 
 if (!apiKey) {
   // eslint-disable-next-line no-console
   console.error(
-    `\n${chalk.red("Missing OpenAI API key.")}\n\n` +
+    `\n${chalk.red(`Missing ${provider} API key.`)}\n\n` +
       `Set the environment variable ${chalk.bold("OPENAI_API_KEY")} ` +
       `and re-run this command.\n` +
       `You can create a key here: ${chalk.bold(
@@ -262,13 +263,11 @@ config = {
   provider,
 };
 
-// Check for updates after loading config
+// Check for updates after loading config. This is important because we write state file in
-// This is important because we write state file in the config dir
+// the config dir.
 await checkForUpdates().catch();
-// ---------------------------------------------------------------------------
-// --flex-mode validation (only allowed for o3 and o4-mini)
-// ---------------------------------------------------------------------------
 
+// For --flex-mode, validate and exit if incorrect.
 if (cli.flags.flexMode) {
   const allowedFlexModels = new Set(["o3", "o4-mini"]);
   if (!allowedFlexModels.has(config.model)) {
@@ -282,13 +281,13 @@ if (cli.flags.flexMode) {
 }
 
 if (
-  !(await isModelSupportedForResponses(config.model)) &&
+  !(await isModelSupportedForResponses(provider, config.model)) &&
   (!provider || provider.toLowerCase() === "openai")
 ) {
   // eslint-disable-next-line no-console
   console.error(
     `The model "${config.model}" does not appear in the list of models ` +
-      `available to your account. Double‑check the spelling (use\n` +
+      `available to your account. Double-check the spelling (use\n` +
       `  openai models list\n` +
       `to see the full list) or choose another model with the --model flag.`,
   );
@@ -297,6 +296,7 @@ if (
 
 let rollout: AppRollout | undefined;
 
+// For --view, optionally load an existing rollout from disk, display it and exit.
 if (cli.flags.view) {
   const viewPath = cli.flags.view;
   const absolutePath = path.isAbsolute(viewPath)
@@ -312,7 +312,7 @@ if (cli.flags.view) {
   }
 }
 
-// If we are running in --fullcontext mode, do that and exit.
+// For --fullcontext, run the separate cli entrypoint and exit.
 if (fullContextMode) {
   await runSinglePass({
     originalPrompt: prompt,
@@ -328,11 +328,8 @@ const additionalWritableRoots: ReadonlyArray<string> = (
   cli.flags.writableRoot ?? []
 ).map((p) => path.resolve(p));
 
-// If we are running in --quiet mode, do that and exit.
+// For --quiet, run the cli without user interactions and exit.
-const quietMode = Boolean(cli.flags.quiet);
+if (cli.flags.quiet) {
-const fullStdout = Boolean(cli.flags.fullStdout);
-
-if (quietMode) {
   process.env["CODEX_QUIET_MODE"] = "1";
   if (!prompt || prompt.trim() === "") {
     // eslint-disable-next-line no-console
@@ -389,7 +386,7 @@ const instance = render(
     imagePaths={imagePaths}
     approvalPolicy={approvalPolicy}
     additionalWritableRoots={additionalWritableRoots}
-    fullStdout={fullStdout}
+    fullStdout={Boolean(cli.flags.fullStdout)}
   />,
   {
     patchConsole: process.env["DEBUG"] ? false : true,
@@ -501,13 +498,13 @@ process.on("SIGQUIT", exit);
 process.on("SIGTERM", exit);
 
 // ---------------------------------------------------------------------------
-// Fallback for Ctrl‑C when stdin is in raw‑mode
+// Fallback for Ctrl-C when stdin is in raw-mode
 // ---------------------------------------------------------------------------
 
 if (process.stdin.isTTY) {
   // Ensure we do not leave the terminal in raw mode if the user presses
-  // Ctrl‑C while some other component has focus and Ink is intercepting
+  // Ctrl-C while some other component has focus and Ink is intercepting
-  // input. Node does *not* emit a SIGINT in raw‑mode, so we listen for the
+  // input. Node does *not* emit a SIGINT in raw-mode, so we listen for the
   // corresponding byte (0x03) ourselves and trigger a graceful shutdown.
   const onRawData = (data: Buffer | string): void => {
     const str = Buffer.isBuffer(data) ? data.toString("utf8") : data;
@@ -518,6 +515,6 @@ if (process.stdin.isTTY) {
   process.stdin.on("data", onRawData);
 }
 
-// Ensure terminal clean‑up always runs, even when other code calls
+// Ensure terminal clean-up always runs, even when other code calls
 // `process.exit()` directly.
 process.once("exit", onExit);

codex-cli/src/components/chat/multiline-editor.tsx

@@ -14,7 +14,7 @@ import React, { useRef, useState } from "react";
  * The real `process.stdin` object exposed by Node.js inherits these methods
  * from `Socket`, but the lightweight stub used in tests only extends
  * `EventEmitter`.  Ink calls the two methods when enabling/disabling raw
- * mode, so make them harmless no‑ops when they're absent to avoid runtime
+ * mode, so make them harmless no-ops when they're absent to avoid runtime
  * failures during unit tests.
  * ----------------------------------------------------------------------- */
 

codex-cli/src/components/chat/terminal-chat-utils.ts

@@ -1,113 +0,0 @@
-import type { ResponseItem } from "openai/resources/responses/responses.mjs";
-
-import { approximateTokensUsed } from "../../utils/approximate-tokens-used.js";
-
-/**
- * Type‑guard that narrows a {@link ResponseItem} to one that represents a
- * user‑authored message. The OpenAI SDK represents both input *and* output
- * messages with a discriminated union where:
- *   • `type` is the string literal "message" and
- *   • `role` is one of "user" | "assistant" | "system" | "developer".
- *
- * For the purposes of de‑duplication we only care about *user* messages so we
- * detect those here in a single, reusable helper.
- */
-function isUserMessage(
-  item: ResponseItem,
-): item is ResponseItem & { type: "message"; role: "user"; content: unknown } {
-  return item.type === "message" && (item as { role?: string }).role === "user";
-}
-
-/**
- * Returns the maximum context length (in tokens) for a given model.
- * These numbers are best‑effort guesses and provide a basis for UI percentages.
- */
-export function maxTokensForModel(model: string): number {
-  const lower = model.toLowerCase();
-  if (lower.includes("32k")) {
-    return 32000;
-  }
-  if (lower.includes("16k")) {
-    return 16000;
-  }
-  if (lower.includes("8k")) {
-    return 8000;
-  }
-  if (lower.includes("4k")) {
-    return 4000;
-  }
-  // Default to 128k for newer long‑context models
-  return 128000;
-}
-
-/**
- * Calculates the percentage of tokens remaining in context for a model.
- */
-export function calculateContextPercentRemaining(
-  items: Array<ResponseItem>,
-  model: string,
-): number {
-  const used = approximateTokensUsed(items);
-  const max = maxTokensForModel(model);
-  const remaining = Math.max(0, max - used);
-  return (remaining / max) * 100;
-}
-
-/**
- * Deduplicate the stream of {@link ResponseItem}s before they are persisted in
- * component state.
- *
- * Historically we used the (optional) {@code id} field returned by the
- * OpenAI streaming API as the primary key: the first occurrence of any given
- * {@code id} “won” and subsequent duplicates were dropped.  In practice this
- * proved brittle because locally‑generated user messages don’t include an
- * {@code id}.  The result was that if a user quickly pressed <Enter> twice the
- * exact same message would appear twice in the transcript.
- *
- * The new rules are therefore:
- *   1.  If a {@link ResponseItem} has an {@code id} keep only the *first*
- *       occurrence of that {@code id} (this retains the previous behaviour for
- *       assistant / tool messages).
- *   2.  Additionally, collapse *consecutive* user messages with identical
- *       content.  Two messages are considered identical when their serialized
- *       {@code content} array matches exactly.  We purposefully restrict this
- *       to **adjacent** duplicates so that legitimately repeated questions at
- *       a later point in the conversation are still shown.
- */
-export function uniqueById(items: Array<ResponseItem>): Array<ResponseItem> {
-  const seenIds = new Set<string>();
-  const deduped: Array<ResponseItem> = [];
-
-  for (const item of items) {
-    // ──────────────────────────────────────────────────────────────────
-    // Rule #1 – de‑duplicate by id when present
-    // ──────────────────────────────────────────────────────────────────
-    if (typeof item.id === "string" && item.id.length > 0) {
-      if (seenIds.has(item.id)) {
-        continue; // skip duplicates
-      }
-      seenIds.add(item.id);
-    }
-
-    // ──────────────────────────────────────────────────────────────────
-    // Rule #2 – collapse consecutive identical user messages
-    // ──────────────────────────────────────────────────────────────────
-    if (isUserMessage(item) && deduped.length > 0) {
-      const prev = deduped[deduped.length - 1]!;
-
-      if (
-        isUserMessage(prev) &&
-        // Note: the `content` field is an array of message parts. Performing
-        // a deep compare is over‑kill here; serialising to JSON is sufficient
-        // (and fast for the tiny payloads involved).
-        JSON.stringify(prev.content) === JSON.stringify(item.content)
-      ) {
-        continue; // skip duplicate user message
-      }
-    }
-
-    deduped.push(item);
-  }
-
-  return deduped;
-}

codex-cli/src/components/chat/terminal-chat.tsx

@@ -6,10 +6,6 @@ import type { ResponseItem } from "openai/resources/responses/responses.mjs";
 
 import TerminalChatInput from "./terminal-chat-input.js";
 import { TerminalChatToolCallCommand } from "./terminal-chat-tool-call-command.js";
-import {
-  calculateContextPercentRemaining,
-  uniqueById,
-} from "./terminal-chat-utils.js";
 import TerminalMessageHistory from "./terminal-message-history.js";
 import { formatCommandForDisplay } from "../../format-command.js";
 import { useConfirmation } from "../../hooks/use-confirmation.js";
@@ -22,7 +18,11 @@ import { extractAppliedPatches as _extractAppliedPatches } from "../../utils/ext
 import { getGitDiff } from "../../utils/get-diff.js";
 import { createInputItem } from "../../utils/input-utils.js";
 import { log } from "../../utils/logger/log.js";
-import { getAvailableModels } from "../../utils/model-utils.js";
+import {
+  getAvailableModels,
+  calculateContextPercentRemaining,
+  uniqueById,
+} from "../../utils/model-utils.js";
 import { CLI_VERSION } from "../../utils/session.js";
 import { shortCwd } from "../../utils/short-path.js";
 import { saveRollout } from "../../utils/storage/save-rollout.js";
@@ -106,11 +106,8 @@ async function generateCommandExplanation(
   } catch (error) {
     log(`Error generating command explanation: ${error}`);
 
-    // Improved error handling with more specific error information
     let errorMessage = "Unable to generate explanation due to an error.";
-
     if (error instanceof Error) {
-      // Include specific error message for better debugging
       errorMessage = `Unable to generate explanation: ${error.message}`;
 
       // If it's an API error, check for more specific information
@@ -141,18 +138,17 @@ export default function TerminalChat({
   additionalWritableRoots,
   fullStdout,
 }: Props): React.ReactElement {
-  // Desktop notification setting
   const notify = config.notify;
   const [model, setModel] = useState<string>(config.model);
   const [provider, setProvider] = useState<string>(config.provider || "openai");
   const [lastResponseId, setLastResponseId] = useState<string | null>(null);
   const [items, setItems] = useState<Array<ResponseItem>>([]);
   const [loading, setLoading] = useState<boolean>(false);
-  // Allow switching approval modes at runtime via an overlay.
   const [approvalPolicy, setApprovalPolicy] = useState<ApprovalPolicy>(
     initialApprovalPolicy,
   );
   const [thinkingSeconds, setThinkingSeconds] = useState(0);
+
   const handleCompact = async () => {
     setLoading(true);
     try {
@@ -185,6 +181,7 @@ export default function TerminalChat({
       setLoading(false);
     }
   };
+
   const {
     requestConfirmation,
     confirmationPrompt,
@@ -215,13 +212,13 @@ export default function TerminalChat({
   // DEBUG: log every render w/ key bits of state
   // ────────────────────────────────────────────────────────────────
   log(
-    `render – agent? ${Boolean(agentRef.current)} loading=${loading} items=${
+    `render - agent? ${Boolean(agentRef.current)} loading=${loading} items=${
       items.length
     }`,
   );
 
   useEffect(() => {
-    // Skip recreating the agent if awaiting a decision on a pending confirmation
+    // Skip recreating the agent if awaiting a decision on a pending confirmation.
     if (confirmationPrompt != null) {
       log("skip AgentLoop recreation due to pending confirmationPrompt");
       return;
@@ -234,7 +231,7 @@ export default function TerminalChat({
       )} approvalPolicy=${approvalPolicy}`,
     );
 
-    // Tear down any existing loop before creating a new one
+    // Tear down any existing loop before creating a new one.
     agentRef.current?.terminate();
 
     const sessionId = crypto.randomUUID();
@@ -267,11 +264,9 @@ export default function TerminalChat({
           <TerminalChatToolCallCommand commandForDisplay={commandForDisplay} />,
         );
 
-        // If the user wants an explanation, generate one and ask again
+        // If the user wants an explanation, generate one and ask again.
         if (review === ReviewDecision.EXPLAIN) {
           log(`Generating explanation for command: ${commandForDisplay}`);
-
-          // Generate an explanation using the same model
           const explanation = await generateCommandExplanation(
             command,
             model,
@@ -279,7 +274,7 @@ export default function TerminalChat({
           );
           log(`Generated explanation: ${explanation}`);
 
-          // Ask for confirmation again, but with the explanation
+          // Ask for confirmation again, but with the explanation.
           const confirmResult = await requestConfirmation(
             <TerminalChatToolCallCommand
               commandForDisplay={commandForDisplay}
@@ -287,11 +282,11 @@ export default function TerminalChat({
             />,
           );
 
-          // Update the decision based on the second confirmation
+          // Update the decision based on the second confirmation.
           review = confirmResult.decision;
           customDenyMessage = confirmResult.customDenyMessage;
 
-          // Return the final decision with the explanation
+          // Return the final decision with the explanation.
           return { review, customDenyMessage, applyPatch, explanation };
         }
 
@@ -299,7 +294,7 @@ export default function TerminalChat({
       },
     });
 
-    // force a render so JSX below can "see" the freshly created agent
+    // Force a render so JSX below can "see" the freshly created agent.
     forceUpdate();
 
     log(`AgentLoop created: ${inspect(agentRef.current, { depth: 1 })}`);
@@ -320,7 +315,7 @@ export default function TerminalChat({
     additionalWritableRoots,
   ]);
 
-  // whenever loading starts/stops, reset or start a timer — but pause the
+  // Whenever loading starts/stops, reset or start a timer — but pause the
   // timer while a confirmation overlay is displayed so we don't trigger a
   // re‑render every second during apply_patch reviews.
   useEffect(() => {
@@ -345,14 +340,15 @@ export default function TerminalChat({
     };
   }, [loading, confirmationPrompt]);
 
-  // Notify desktop with a preview when an assistant response arrives
+  // Notify desktop with a preview when an assistant response arrives.
   const prevLoadingRef = useRef<boolean>(false);
   useEffect(() => {
-    // Only notify when notifications are enabled
+    // Only notify when notifications are enabled.
     if (!notify) {
       prevLoadingRef.current = loading;
       return;
     }
+
     if (
       prevLoadingRef.current &&
       !loading &&
@@ -389,7 +385,7 @@ export default function TerminalChat({
     prevLoadingRef.current = loading;
   }, [notify, loading, confirmationPrompt, items, PWD]);
 
-  // Let's also track whenever the ref becomes available
+  // Let's also track whenever the ref becomes available.
   const agent = agentRef.current;
   useEffect(() => {
     log(`agentRef.current is now ${Boolean(agent)}`);
@@ -412,7 +408,7 @@ export default function TerminalChat({
       const inputItems = [
         await createInputItem(initialPrompt || "", initialImagePaths || []),
       ];
-      // Clear them to prevent subsequent runs
+      // Clear them to prevent subsequent runs.
       setInitialPrompt("");
       setInitialImagePaths([]);
       agent?.run(inputItems);
@@ -447,7 +443,7 @@ export default function TerminalChat({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
-  // Just render every item in order, no grouping/collapse
+  // Just render every item in order, no grouping/collapse.
   const lastMessageBatch = items.map((item) => ({ item }));
   const groupCounts: Record<string, number> = {};
   const userMsgCount = items.filter(
@@ -626,10 +622,10 @@ export default function TerminalChat({
               agent?.cancel();
               setLoading(false);
 
-              // Select default model for the new provider
+              // Select default model for the new provider.
               const defaultModel = model;
 
-              // Save provider to config
+              // Save provider to config.
               const updatedConfig = {
                 ...config,
                 provider: newProvider,
@@ -669,13 +665,12 @@ export default function TerminalChat({
           <ApprovalModeOverlay
             currentMode={approvalPolicy}
             onSelect={(newMode) => {
-              // update approval policy without cancelling an in-progress session
+              // Update approval policy without cancelling an in-progress session.
               if (newMode === approvalPolicy) {
                 return;
               }
-              // update state
+
               setApprovalPolicy(newMode as ApprovalPolicy);
-              // update existing AgentLoop instance
               if (agentRef.current) {
                 (
                   agentRef.current as unknown as {

codex-cli/src/components/chat/terminal-header.tsx

@@ -34,9 +34,9 @@ const TerminalHeader: React.FC<TerminalHeaderProps> = ({
       {terminalRows < 10 ? (
         // Compact header for small terminal windows
         <Text>
-          ● Codex v{version} – {PWD} – {model} ({provider}) –{" "}
+          ● Codex v{version} - {PWD} - {model} ({provider}) -{" "}
           <Text color={colorsByPolicy[approvalPolicy]}>{approvalPolicy}</Text>
-          {flexModeEnabled ? " – flex-mode" : ""}
+          {flexModeEnabled ? " - flex-mode" : ""}
         </Text>
       ) : (
         <>

codex-cli/src/components/singlepass-cli-app.tsx

@@ -399,8 +399,8 @@ export function SinglePassApp({
       });
 
       const openai = new OpenAI({
-        apiKey: getApiKey(config.provider),
+        apiKey: getApiKey(config.provider ?? "openai"),
-        baseURL: getBaseUrl(config.provider),
+        baseURL: getBaseUrl(config.provider ?? "openai"),
         timeout: OPENAI_TIMEOUT_MS,
       });
       const chatResp = await openai.beta.chat.completions.parse({

codex-cli/src/hooks/use-confirmation.ts

@@ -1,4 +1,3 @@
-// use-confirmation.ts
 import type { ReviewDecision } from "../utils/agent/review";
 import type React from "react";
 

codex-cli/src/text-buffer.ts

@@ -423,7 +423,7 @@ export default class TextBuffer {
   /** Delete the word to the *left* of the caret, mirroring common
    *  Ctrl/Alt+Backspace behaviour in editors & terminals.  Both the adjacent
    *  whitespace *and* the word characters immediately preceding the caret are
-   *  removed.  If the caret is already at column‑0 this becomes a no‑op. */
+   *  removed.  If the caret is already at column‑0 this becomes a no-op. */
   deleteWordLeft(): void {
     dbg("deleteWordLeft", { beforeCursor: this.getCursor() });
 
@@ -710,7 +710,7 @@ export default class TextBuffer {
   }
 
   endSelection(): void {
-    // no‑op for now, kept for API symmetry
+    // no-op for now, kept for API symmetry
     // we rely on anchor + current cursor to compute selection
   }
 

codex-cli/src/utils/agent/agent-loop.ts

@@ -744,7 +744,7 @@ export class AgentLoop {
           for await (const event of stream as AsyncIterable<ResponseEvent>) {
             log(`AgentLoop.run(): response event ${event.type}`);
 
-            // process and surface each item (no‑op until we can depend on streaming events)
+            // process and surface each item (no-op until we can depend on streaming events)
             if (event.type === "response.output_item.done") {
               const item = event.item;
               // 1) if it's a reasoning item, annotate it
@@ -936,7 +936,7 @@ export class AgentLoop {
             ],
           });
         } catch {
-          /* no‑op – emitting the error message is best‑effort */
+          /* no-op – emitting the error message is best‑effort */
         }
         this.onLoading(false);
         return;

codex-cli/src/utils/agent/handle-exec-command.ts

@@ -144,7 +144,7 @@ export async function handleExecCommand(
     abortSignal,
   );
   // If the operation was aborted in the meantime, propagate the cancellation
-  // upward by returning an empty (no‑op) result so that the agent loop will
+  // upward by returning an empty (no-op) result so that the agent loop will
   // exit cleanly without emitting spurious output.
   if (abortSignal?.aborted) {
     return {

codex-cli/src/utils/config.ts

@@ -41,7 +41,7 @@ export function setApiKey(apiKey: string): void {
   OPENAI_API_KEY = apiKey;
 }
 
-export function getBaseUrl(provider: string = "openai"): string | undefined {
+export function getBaseUrl(provider: string): string | undefined {
   const providerInfo = providers[provider.toLowerCase()];
   if (providerInfo) {
     return providerInfo.baseURL;
@@ -49,7 +49,7 @@ export function getBaseUrl(provider: string = "openai"): string | undefined {
   return undefined;
 }
 
-export function getApiKey(provider: string = "openai"): string | undefined {
+export function getApiKey(provider: string): string | undefined {
   const providerInfo = providers[provider.toLowerCase()];
   if (providerInfo) {
     if (providerInfo.name === "Ollama") {

codex-cli/src/utils/model-utils.ts

@@ -1,3 +1,6 @@
+import type { ResponseItem } from "openai/resources/responses/responses.mjs";
+
+import { approximateTokensUsed } from "./approximate-tokens-used.js";
 import { getBaseUrl, getApiKey } from "./config";
 import OpenAI from "openai";
 
@@ -11,9 +14,8 @@ export const RECOMMENDED_MODELS: Array<string> = ["o4-mini", "o3"];
  * enters interactive mode.  The request is made exactly once during the
  * lifetime of the process and the results are cached for subsequent calls.
  */
-
 async function fetchModels(provider: string): Promise<Array<string>> {
-  // If the user has not configured an API key we cannot hit the network.
+  // If the user has not configured an API key we cannot retrieve the models.
   if (!getApiKey(provider)) {
     throw new Error("No API key configured for provider: " + provider);
   }
@@ -26,7 +28,7 @@ async function fetchModels(provider: string): Promise<Array<string>> {
     for await (const model of list as AsyncIterable<{ id?: string }>) {
       if (model && typeof model.id === "string") {
         let modelStr = model.id;
-        // fix for gemini
+        // Fix for gemini.
         if (modelStr.startsWith("models/")) {
           modelStr = modelStr.replace("models/", "");
         }
@@ -40,6 +42,7 @@ async function fetchModels(provider: string): Promise<Array<string>> {
   }
 }
 
+/** Returns the list of models available for the provided key / credentials. */
 export async function getAvailableModels(
   provider: string,
 ): Promise<Array<string>> {
@@ -47,11 +50,11 @@ export async function getAvailableModels(
 }
 
 /**
- * Verify that the provided model identifier is present in the set returned by
+ * Verifies that the provided model identifier is present in the set returned by
- * {@link getAvailableModels}. The list of models is fetched from the OpenAI
+ * {@link getAvailableModels}.
- * `/models` endpoint the first time it is required and then cached in‑process.
  */
 export async function isModelSupportedForResponses(
+  provider: string,
   model: string | undefined | null,
 ): Promise<boolean> {
   if (
@@ -64,7 +67,7 @@ export async function isModelSupportedForResponses(
 
   try {
     const models = await Promise.race<Array<string>>([
-      getAvailableModels("openai"),
+      getAvailableModels(provider),
       new Promise<Array<string>>((resolve) =>
         setTimeout(() => resolve([]), MODEL_LIST_TIMEOUT_MS),
       ),
@@ -82,3 +85,110 @@ export async function isModelSupportedForResponses(
     return true;
   }
 }
+
+/** Returns the maximum context length (in tokens) for a given model. */
+function maxTokensForModel(model: string): number {
+  // TODO: These numbers are best‑effort guesses and provide a basis for UI percentages. They
+  // should be provider & model specific instead of being wild guesses.
+
+  const lower = model.toLowerCase();
+  if (lower.includes("32k")) {
+    return 32000;
+  }
+  if (lower.includes("16k")) {
+    return 16000;
+  }
+  if (lower.includes("8k")) {
+    return 8000;
+  }
+  if (lower.includes("4k")) {
+    return 4000;
+  }
+  return 128000; // Default to 128k for any other model.
+}
+
+/** Calculates the percentage of tokens remaining in context for a model. */
+export function calculateContextPercentRemaining(
+  items: Array<ResponseItem>,
+  model: string,
+): number {
+  const used = approximateTokensUsed(items);
+  const max = maxTokensForModel(model);
+  const remaining = Math.max(0, max - used);
+  return (remaining / max) * 100;
+}
+
+/**
+ * Type‑guard that narrows a {@link ResponseItem} to one that represents a
+ * user‑authored message. The OpenAI SDK represents both input *and* output
+ * messages with a discriminated union where:
+ *   • `type` is the string literal "message" and
+ *   • `role` is one of "user" | "assistant" | "system" | "developer".
+ *
+ * For the purposes of de‑duplication we only care about *user* messages so we
+ * detect those here in a single, reusable helper.
+ */
+function isUserMessage(
+  item: ResponseItem,
+): item is ResponseItem & { type: "message"; role: "user"; content: unknown } {
+  return item.type === "message" && (item as { role?: string }).role === "user";
+}
+
+/**
+ * Deduplicate the stream of {@link ResponseItem}s before they are persisted in
+ * component state.
+ *
+ * Historically we used the (optional) {@code id} field returned by the
+ * OpenAI streaming API as the primary key: the first occurrence of any given
+ * {@code id} “won” and subsequent duplicates were dropped.  In practice this
+ * proved brittle because locally‑generated user messages don’t include an
+ * {@code id}.  The result was that if a user quickly pressed <Enter> twice the
+ * exact same message would appear twice in the transcript.
+ *
+ * The new rules are therefore:
+ *   1.  If a {@link ResponseItem} has an {@code id} keep only the *first*
+ *       occurrence of that {@code id} (this retains the previous behaviour for
+ *       assistant / tool messages).
+ *   2.  Additionally, collapse *consecutive* user messages with identical
+ *       content.  Two messages are considered identical when their serialized
+ *       {@code content} array matches exactly.  We purposefully restrict this
+ *       to **adjacent** duplicates so that legitimately repeated questions at
+ *       a later point in the conversation are still shown.
+ */
+export function uniqueById(items: Array<ResponseItem>): Array<ResponseItem> {
+  const seenIds = new Set<string>();
+  const deduped: Array<ResponseItem> = [];
+
+  for (const item of items) {
+    // ──────────────────────────────────────────────────────────────────
+    // Rule #1 – de‑duplicate by id when present
+    // ──────────────────────────────────────────────────────────────────
+    if (typeof item.id === "string" && item.id.length > 0) {
+      if (seenIds.has(item.id)) {
+        continue; // skip duplicates
+      }
+      seenIds.add(item.id);
+    }
+
+    // ──────────────────────────────────────────────────────────────────
+    // Rule #2 – collapse consecutive identical user messages
+    // ──────────────────────────────────────────────────────────────────
+    if (isUserMessage(item) && deduped.length > 0) {
+      const prev = deduped[deduped.length - 1]!;
+
+      if (
+        isUserMessage(prev) &&
+        // Note: the `content` field is an array of message parts. Performing
+        // a deep compare is over‑kill here; serialising to JSON is sufficient
+        // (and fast for the tiny payloads involved).
+        JSON.stringify(prev.content) === JSON.stringify(item.content)
+      ) {
+        continue; // skip duplicate user message
+      }
+    }
+
+    deduped.push(item);
+  }
+
+  return deduped;
+}

codex-cli/tests/agent-project-doc.test.ts

@@ -50,7 +50,7 @@ vi.mock("openai", () => {
 
 // The AgentLoop pulls these helpers in order to decide whether a command can
 // be auto‑approved. None of that matters for this test, so we stub the module
-// with minimal no‑op implementations.
+// with minimal no-op implementations.
 vi.mock("../src/approvals.js", () => {
   return {
     __esModule: true,

codex-cli/tests/approvals.test.ts

@@ -79,7 +79,7 @@ describe("canAutoApprove()", () => {
   test("true command is considered safe", () => {
     expect(check(["true"])).toEqual({
       type: "auto-approve",
-      reason: "No‑op (true)",
+      reason: "No-op (true)",
       group: "Utility",
       runInSandbox: false,
     });

codex-cli/tests/config.test.tsx

@@ -26,7 +26,7 @@ vi.mock("fs", async () => {
       memfs[path] = data;
     },
     mkdirSync: () => {
-      // no‑op in in‑memory store
+      // no-op in in‑memory store
     },
     rmSync: (path: string) => {
       // recursively delete any key under this prefix

codex-cli/tests/model-utils-network-error.test.ts

@@ -44,7 +44,7 @@ describe("model-utils – offline resilience", () => {
       "../src/utils/model-utils.js"
     );
 
-    const supported = await isModelSupportedForResponses("o4-mini");
+    const supported = await isModelSupportedForResponses("openai", "o4-mini");
     expect(supported).toBe(true);
   });
 
@@ -63,8 +63,11 @@ describe("model-utils – offline resilience", () => {
       "../src/utils/model-utils.js"
     );
 
-    // Should resolve true despite the network failure
+    // Should resolve true despite the network failure.
-    const supported = await isModelSupportedForResponses("some-model");
+    const supported = await isModelSupportedForResponses(
+      "openai",
+      "some-model",
+    );
     expect(supported).toBe(true);
   });
 });

codex-cli/tests/multiline-history-behavior.test.tsx

@@ -57,7 +57,7 @@ async function type(
   await flush();
 }
 
-/** Build a set of no‑op callbacks so <TerminalChatInput> renders with minimal
+/** Build a set of no-op callbacks so <TerminalChatInput> renders with minimal
  *  scaffolding.
  */
 function stubProps(): any {

codex-cli/tests/text-buffer.test.ts

@@ -127,7 +127,7 @@ describe("TextBuffer – basic editing parity with Rust suite", () => {
       expect(buf.getCursor()).toEqual([0, 2]); // after 'b'
     });
 
-    it("is a no‑op at the very beginning of the buffer", () => {
+    it("is a no-op at the very beginning of the buffer", () => {
       const buf = new TextBuffer("ab");
       buf.backspace(); // caret starts at (0,0)
 

codex-cli/tests/typeahead-scroll.test.tsx

@@ -26,7 +26,7 @@ vi.mock("../src/components/select-input/select-input.js", () => {
 
 // Ink's <TextInput> toggles raw‑mode which calls .ref() / .unref() on stdin.
 // The test environment's mock streams don't implement those methods, so we
-// polyfill them to no‑ops on the prototype *before* the component tree mounts.
+// polyfill them to no-ops on the prototype *before* the component tree mounts.
 import { EventEmitter } from "node:events";
 if (!(EventEmitter.prototype as any).ref) {
   (EventEmitter.prototype as any).ref = () => {};