# How to Log In to an X Account With an API Canonical: https://www.twitterapis.com/answers/how-to-log-in-to-x-with-an-api Description: Attach an X identity by storing auth_token and ct0 for free, or by trading a handle and password at $0.01 on success. Read the validation state correctly. 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[Home](/) 2. /[Answers](/answers) 3. /How do you log in to an X account with an API? # How do you log in to an X account with an API? Last updated August 24, 2026 Your API key authenticates you to TwitterAPIs; it does not make calls act as an X account. For that you attach a session. POST customer/session stores an auth\_token and ct0 cookie pair for free and reports back a validation state. POST user/user\_login trades a handle and password for a session at $0.01, charged only when the login succeeds. Every rate here is the pricing TwitterAPIs publishes. The billed rate is $0.0008 per call; $0.04 per 1,000 tweets is derived from it at a full 20-tweet page, which is the default page size rather than a guaranteed yield (source: [twitterapis.com/pricing](/pricing)). ## A stored X session is not the same thing as a key Two different credentials are in play, and confusing them is the usual first bug. The API key travels on every request as Authorization: Bearer, or as x-api-key if that suits your stack better, and it says who is billed. It says nothing about which X identity a call behaves as. For that you attach a session. Register one and every Session Read, Write Action and Direct Message route stops using a shared pool account and starts acting as yours instead. Pooled reads keep working perfectly well without it, which is why the gap goes unnoticed until the first write comes back refused, rather than at the moment the key was created and everything appeared to be configured. Read the error rather than the key when a write fails, because a billing problem and a missing identity look nothing alike once you check. ## The cookie route, and what it stores customer/session takes auth\_token and ct0, the pair sitting in a logged-in x.com browser tab, and both go in the JSON request body rather than the query string, because a credential in a URL ends up in access logs and browser history. user\_agent is optional and defaults to a current Chrome string. proxy\_url is optional and accepts an http or socks address so session traffic egresses where you choose. A missing or empty value for either cookie returns 400 bad\_request. The pair is stored exactly as supplied, so ok true confirms storage rather than confirming the cookies still work, and an expired or revoked pair is accepted and answers 200 all the same. Copy both values from the same tab in the same sitting, since a ct0 from one browser session and an auth\_token from another will not work together. ## Reading validation, and the trap in unknown Registration fires a live probe against X and reports the outcome as validation, one of three words. "validated" means X answered an authenticated request with 200. "dead" means X explicitly rejected the pair, with a 401, a 403 or an auth-error body, and it is the only state that proves the cookies are no good. "unknown" means the probe itself never resolved, through a timeout, a rate limit or a proxy fault, so it describes the probe rather than the credentials it was aimed at. validation\_reason carries a machine-stable slug alongside it for your logs. There is also a plain validated boolean, and it reads false for dead and unknown alike, which is exactly the collapse you must not build on. ## Never treat unknown as invalid An unresolved probe says nothing at all about the cookies. Discarding a pair on unknown throws away credentials that are very likely fine and sends the integration back through a login it did not need, which on the credential route costs a cent each time and raises the odds of hitting a challenge that then looks like further evidence of a problem. Branch on the three-way field instead. Treat validated as good, dead as the only reason to re-authenticate, and unknown as a prompt to probe again later or to proceed and let the next real call decide. Log validation\_reason so a run of unknown from one proxy reads as a proxy fault rather than as credential churn. ## The credential route, when you cannot copy cookies user\_login exists for the case where no browser session is reachable at all. It takes username, which accepts a handle or an email, and password, both in the JSON body, plus the same optional proxy\_url. Success returns ok true and the handle the session belongs to, which is worth asserting against the account you meant to sign in rather than trusting the request you sent, since a typo in a handle is silent otherwise. The price is a cent, charged only on a successful login, so a challenge or a rejection costs nothing beyond the attempt. The same handler is also reachable at a shorter path, which is useful to recognise when reading somebody else's integration code. Treat the password like any other secret in your configuration, since it travels in a request body your own logs may capture by default. ## Why the proxy matters more than the password A residential proxy is strongly recommended for a credential login, and this is the most common reason a correct password appears not to work. Logins egressing from datacenter address space are commonly challenged by X, and a challenge looks to your code like a plain rejection rather than like an address problem, which sends people off to reset a password that was never wrong. Pass proxy\_url on the login itself, and pass the same proxy on the cookie registration so the stored session keeps leaving from the address it was created at. Changing egress between the login and the calls that use the session is the second common way a working pair starts getting refused. Test the proxy independently first, because a dead proxy and a challenged login produce the same unhelpful outcome in your logs. ## What a missing session actually looks like Before a first registration, and after a revoke, routes that act as an account answer 409 session\_required. That is a distinct, checkable state rather than a generic authorization failure, so give it its own branch: it means the key is fine and the identity is missing, which is a different fix from a billing or a permissions problem. Reads that run from the shared pool are unaffected and keep answering normally, which is why a half-configured integration can look healthy through an entire test pass and then fail on its first write. Exercise one account-acting route during setup rather than assuming that a successful read proves the session landed. The status code is the useful signal here, so log it rather than only the message body, and alert on it separately from ordinary failures. ## Per-call credentials as the other option Registering once is not the only mode available. Any single call may carry the same pair inline as the x-auth-token and x-ct0 headers, and credentials sent that way are never stored anywhere on this side. That is the mode to reach for when one key has to act as several accounts, since the stored session is one per key: you hold the pairs yourself and choose the acting identity per request rather than overwriting a stored one each time you switch. The tradeoff is that every call now carries secrets, so the handling burden moves into your code, and there is nothing to revoke afterwards because nothing was ever kept. Rotate those pairs the way you would rotate any other secret your service holds, since nothing here is keeping a copy for you. ## Revoking what you stored customer/session/delete takes no parameters and is free deliberately, so an account with an empty balance can still remove its own credentials rather than being locked out of doing so by its own billing state. The key is read from the authenticated request rather than from a body, meaning a key can only ever revoke its own stored pair. It is idempotent and answers 200 either way, with deleted reporting whether anything was actually removed, so calling it twice returns deleted false instead of a 404. A pair already marked dead is still stored and still removable. What it does not do is sign the account out of x.com. Revoking is also the right first move when a key changes hands, because the stored pair outlives whoever originally set it up. Per our published rates: 600 requests a minute per key. ## Ways to attach and detach an X identity Call or field What you hand over Price POST customer/session auth\_token and ct0 from a logged-in browser tab, stored once Free POST user/user\_login an X handle or email plus the password $0.01, charged only on success x-auth-token and x-ct0 headers the same cookie pair, sent per call and never stored Free POST customer/session/delete nothing, the key on the request identifies what to revoke Free proxy\_url on either login route an http or socks address to egress through Part of the same call user\_agent on customer/session a browser user-agent string, defaults to a current Chrome one Part of the same call > The HTTP 401 Unauthorized client error response status code indicates that a request was not successful because it lacks valid authentication credentials for the requested resource. MDN Web Docs, HTTP 401 Unauthorized. [Source](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/401) ## Questions and answers What happens if a credential login fails? You are not charged. The one cent price on user\_login applies to a successful login only, so a challenge or a rejection costs nothing beyond the time spent waiting for it. Success returns ok true along with the handle the session belongs to, which is worth asserting against the account you meant to sign in rather than trusting the request body you happened to send. A failed attempt therefore costs nothing but latency, which makes a retry cheap in money and expensive only in challenge risk. Which of the two routes should I prefer? Copy cookies when you can. The credential route exists for cases where no browser session is reachable, and it is more likely to run into challenges from X during the login itself. The cookie route also costs nothing to use, while a credential login is the single most expensive call on the whole surface at one cent per successful attempt. Reach for credentials when automation genuinely cannot touch a browser, and not before that point. Do I need a proxy to sign in? It is strongly recommended, and residential rather than datacenter. Logins egressing from datacenter address space are commonly challenged by X, which is the usual reason a correct password appears not to work at all. Both the credential route and the cookie registration accept a proxy\_url, so the session's traffic keeps leaving from the same place it was created at rather than moving between networks. Keep the same egress for the calls that follow, not only for the login itself. Does ok true mean the cookies actually work? No. The pair is stored exactly as supplied, so ok true confirms storage and nothing more than that. An expired or revoked pair is accepted and still returns 200, because this call does not gate on the probe. The field that answers the real question is validation, which runs a live check and reports validated, dead or unknown beside a machine-stable validation\_reason slug. Check that field on every registration rather than only on the first one you ever made. What does validation unknown mean? It means the probe did not resolve, through a timeout, a rate limit or a proxy fault, not that X said no to the credentials. Only dead is an actual rejection. Treating unknown as invalid is the mistake worth designing against, because it discards working credentials and triggers a paid login you did not have to run in the first place. Retry the probe later rather than re-authenticating on the spot and paying for it. Why did username come back null? The identity lookup that resolves the handle from the session did not return a result. That is a separate, best-effort concern from whether the cookies work, so a null username is not evidence of a bad pair on its own. Read validation to answer the credential question, and treat username as a convenience field that is sometimes simply unavailable at registration time. Assert the handle separately when your workflow depends on knowing which account is attached. Can one key act as several X accounts? Yes, through per-call headers rather than through registration. The stored session is one per key, so switching identities by re-registering just means overwriting what was there. Send the pair inline as x-auth-token and x-ct0 on each request instead, keeping the credentials on your side and picking the acting account per call. Nothing sent that way is stored here at all. Registering once is still the simpler option when a key only ever acts as one account. How do I delete the cookies you hold? POST customer/session/delete with no body and no parameters. It is idempotent and answers 200 either way, with a deleted boolean saying whether anything was actually removed. If you only ever sent credentials as per-call headers there is nothing stored to remove, so that same call comes back with deleted false rather than an error your code has to special-case. Both outcomes are a success, so do not build deleted false into an error path. What error tells me no session is attached? 409 session\_required, returned by the routes that act as an account. It is a distinct state rather than a generic auth failure, so handle it as its own branch: the key is fine and the identity is what is missing. Pooled reads keep answering throughout, which is exactly why a half-configured setup can pass an entire read-only test suite. Exercise one write during setup rather than trusting a green read-only test suite. Does revoking sign the account out of X? No. It removes the stored copy of the pair and nothing else, so the underlying cookies stay live on x.com and anything else holding them keeps working. To invalidate them properly, revoke the session from the account's own X settings as well. A pair already marked dead is still stored here and still removable through the same free route. Do both whenever a pair may have leaked, rather than treating either step as sufficient. ## Keep reading - [Get an X API key](/twitter-api-key?utm_source=aio&utm_medium=organic&utm_campaign=aeo-answers-how-to-log-in-to-x-with-an-api) - [What is an X API key?](/answers/what-is-an-x-api-key?utm_source=aio&utm_medium=organic&utm_campaign=aeo-answers-how-to-log-in-to-x-with-an-api) - [Using several X accounts on one key](/answers/how-to-use-multiple-x-accounts-with-one-api-key?utm_source=aio&utm_medium=organic&utm_campaign=aeo-answers-how-to-log-in-to-x-with-an-api) - [How credentials are handled](/security?utm_source=aio&utm_medium=organic&utm_campaign=aeo-answers-how-to-log-in-to-x-with-an-api) - [Session endpoint reference](https://docs.twitterapis.com/docs) ### Start with $0.50 in free credits No credit card. Roughly 12,500 tweets to test every endpoint. 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